COMMUNICATOR AND COMMUNICATION DEVICE

A communicator (relay) receives a differential signal that is a voltage difference between two electrical signals that propagate through two respective conducting wires. The communicator removes noise from the two electrical signals using a first conductor as a reference potential. The communicator converts the differential signal that is the voltage difference between the two electrical signals with the noise removed into a voltage signal that is a voltage with the reference potential corresponding to a potential of a second conductor. The first conductor and the second conductor are respectively disposed on a first substrate and a second substrate. The first substrate and the second substrate are connected via a substrate connector with flexibility.

TECHNICAL FIELD

The present disclosure relates to a communicator and a communication device.

BACKGROUND

The communicator for a vehicle described in JP 2020-167536A receives a differential signal expressed by a voltage difference of two electrical signals that propagate via two conducting wires. With the communicator, using the potential of a first conductor as a reference potential, noise is removed from the two electrical signals. Also, the differential signal expressed by the voltage difference of the two electrical signals with the noise removed is converted to a voltage signal expressed by a voltage with the reference potential corresponding to the potential of a second conductor. The first conductor and the second conductor are disposed inside a single substrate. On one substrate of the substrate, a plurality of circuit elements required for noise removal and conversion are disposed.

In the communicator according to JP 2020-167536A, a plurality of circuit elements are disposed on one substrate. Thus, the area of the installation surface of the communicator is large. The communicator is installed in vehicles of various types with different shapes. In some cases, a communicator with a small area for the installation surface may be preferable.

An object is to provide a communicator and a communication device that can implement a reduction in the area of an installation surface.

SUMMARY

A communicator according to an aspect of the present disclosure is a communicator for receiving a differential signal that is a voltage difference between two electrical signals that propagate through two respective conducting wires, including: a noise removal circuit configured to remove noise from the two electrical signals using a potential of a first conductor as a reference potential; a conversion unit configured to convert a differential signal that is a voltage difference between two electrical signals with noise removed by the noise removal circuit into a voltage signal that is a voltage with a reference potential corresponding to a potential of a second conductor; a first substrate on which the first conductor is disposed; a second substrate on which the second conductor is disposed; and a substrate connector with flexibility that connects the first substrate and the second substrate.

A communication device according to an aspect of the present disclosure includes: a communicator that receives a differential signal expressed by a voltage difference of two electrical signals that propagate along two conducting wires; and a power supply apparatus that supplies power to the communicator, wherein the communicator includes a noise removal circuit that removes noise from the two electrical signals using a potential of a first conductor as a reference potential, a conversion unit that converts a differential signal expressed by a voltage difference of two electrical signals with noise removed by the noise removal circuit into a voltage signal expressed by a voltage with a reference potential corresponding to a potential of a second conductor, a first substrate where the first conductor is disposed, a second substrate where the second conductor is disposed, a substrate connector with flexibility that connects the first substrate and the second substrate, and an apparatus connector that connects the second substrate and a power supply apparatus, and the power supply apparatus supplies power to the conversion unit via the apparatus connector.

Advantageous Effects

According to the present disclosure, a reduction in the area of an installation surface can be implemented.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Firstly, embodiments of the present disclosure will be listed and described. One or more parts of the embodiments described below may be combined in a discretionary manner.

A communicator according to an aspect of the present disclosure is a communicator for receiving a differential signal that is a voltage difference between two electrical signals that propagate through two respective conducting wires, including: a noise removal circuit configured to remove noise from the two electrical signals using a potential of a first conductor as a reference potential; a conversion unit configured to convert a differential signal that is a voltage difference between two electrical signals with noise removed by the noise removal circuit into a voltage signal that is a voltage with a reference potential corresponding to a potential of a second conductor; a first substrate on which the first conductor is disposed; a second substrate on which the second conductor is disposed; and a substrate connector with flexibility that connects the first substrate and the second substrate.

According to the aspect described above, the first substrate and the second substrate are connected via the substrate connector which is flexible. Thus, the flexibility relating to how to arrange the first substrate and the second substrate is high. Accordingly, the first substrate and the second substrate can be arranged so that the area of the installation surface is reduced.

In the communicator according to an aspect of the present disclosure, the differential signal is a signal for communication compliant with an Ethernet (registered trademark) communication protocol, a signal for communication using low voltage differential signalling (LVDS), or a signal for communication compliant with universal serial bus (USB).

According to the aspect described above, a signal for communication compliant with the Ethernet communication protocol, a signal for communication using LVDS, or a signal for communication compliant with USB is received.

The communicator according to an aspect of the present disclosure further includes a conductor connecting element connected between the first conductor and the second conductor, wherein the conductor connecting element is an inductor, a resistor, or a conducting wire.

According to the aspect described above, when noise enters the first conductor, even when the potential of the first conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second conductor. In a similar manner, when noise enters the second conductor, even when the potential of the second conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the first conductor.

In the communicator according to an aspect of the present disclosure, a first circuit element is disposed on a surface of the first substrate, a second circuit element is disposed on a surface of the second substrate, and the surface of the first substrate on which the first circuit element is disposed faces the surface of the second substrate on which the second circuit element is disposed.

According to the aspect described above, by making one surface of the first substrate and one surface of the second substrate face one another, the area of the installation surface is reduced.

In the communicator according to an aspect of the present disclosure, a first circuit element is disposed on a surface of the first substrate, a second circuit element is disposed on a surface of the second substrate, and the surface of the first substrate on which the first circuit element is disposed and the surface of the second substrate on which the second circuit element is disposed are perpendicular to one another.

According to the aspect described above, the first substrate and the second substrate are disposed so that one surface of the first substrate and one surface of the second substrate are perpendicular to one another, thus reducing the area of the installation surface.

The communicator according to an aspect of the present disclosure further includes a box with electrical conductivity that houses the first substrate and the second substrate; and a projection portion projecting outward from the box, the projection portion being used for fixing the box, wherein the projection portion has electrical conductivity and is conductively connected to the first conductor via the box.

According to the aspect described above, the projection portion is connected to the substrate via soldering, for example. Accordingly, the projection portion can be conductively connected to the conductor disposed on the substrate. In this case, the first conductor is conductively connected to the conductor of the substrate via the box and the projection portion.

In the communicator according to an aspect of the present disclosure, the projection portion is provided with a through hole through which a screw with electrical conductivity is inserted, the box is fixed by the screw being tightened, and when the box is fixed, the screw is conductively connected to the projection portion.

According to the aspect described above, the screw is passed through the through hole of the projection portion. Thereafter, the screw is tightened on the substrate, for example. Accordingly, the screw is brought into contact with the projection portion with electrical conductivity, and the box is fixed to the substrate. For example, the screw is conductively connected to the conductor inside the substrate. In this case, the first conductor is conductively connected to the conductor of the substrate via the box, the projection portion, and the screw.

The communicator according to an aspect of the present disclosure further includes a second projection portion with electrical conductivity that projects outward from the box, the second projection portion being used for fixing the box, wherein the box includes a first conductive portion with electrical conductivity conductively connected to the first conductor, a second conductive portion with electrical conductivity conductively connected to the second conductor, and a connection portion with electrical conductivity that connects the first conductive portion and the second conductive portion, the projection portion projects from the first conductive portion, and the second projection portion projects from the second conductive portion.

According to the aspect described above, regarding the box, the first conductive portion is connected to the second conductive portion via the connection portion with insulating properties. The projection portion and the second projection portion can be conductively connected to the two conductors.

The communicator according to an aspect of the present disclosure further includes a conductive rod with electrical conductivity, wherein the first substrate is provided with an insertion hole through which the conductive rod is inserted, and the conductive rod is inserted into the insertion hole and conductively connected to the first conductor.

According to the aspect described above, the conductive rod is inserted into the insertion hole of the first substrate. The conductive rod is inserted into the insertion hole of the substrate of another apparatus, for example. In the two insertion holes, the conductive rods are connected to the first substrate and the substrate of another apparatus via soldering, for example. Accordingly, the first conductor of the first substrate is conductively connected to the conductor of the substrate via the conductive rod.

The communicator according to an aspect of the present disclosure further includes an apparatus connector that connects the second substrate and an external apparatus, wherein the conversion unit is supplied with power via the apparatus connector.

According to the aspect described above, power is supplied to the conversion unit from an external apparatus via the apparatus connector.

In the communicator according to an aspect of the present disclosure, the apparatus connector includes a second conductive rod with electrical conductivity, and the second substrate is provided with a second insertion hole through which the second conductive rod is inserted.

According to the aspect described above, the second conductive rod is connected to an external apparatus and the conversion unit. Power is supplied to the conversion unit from an external apparatus via the second conductive rod.

In the communicator according to an aspect of the present disclosure, the apparatus connector is an edge connector that projects from the second substrate.

According to the aspect described above, the apparatus connector is inserted into a recess portion provided in an external apparatus. In this manner, the apparatus connector is connected to an external apparatus.

In the communicator according to an aspect of the present disclosure, the apparatus connector has a plate-like shape and flexibility, and an end portion of the apparatus connector is installed on the second substrate.

According to the aspect described above, the end portion of the apparatus connector is connected to an external apparatus. Since the apparatus connector has flexibility, the connection can be easily implemented.

The communicator according to an aspect of the present disclosure further includes a communication line connector connected to a communication line including two conducting wires, wherein the differential signal is input into the noise removal circuit via the communication line and the communication line connector.

According to the aspect described above, noise is removed from the two electrical signals forming the differential signal input via the communication line and the communication line connector.

In the communicator according to an aspect of the present disclosure, the communication line connector is an edge connector that projects from the first substrate.

According to the aspect described above, the communication line connector is inserted into a hole provided in a cable including the communication line, for example. In this manner, the communication line connector is connected to the communication line.

A communication device according to an aspect of the present disclosure includes: a communicator that receives a differential signal that is a voltage difference between two electrical signals that propagate through two respective conducting wires; and a power supply apparatus configured to supply power to the communicator, wherein the communicator includes a noise removal circuit configured to remove noise from the two electrical signals using a potential of a first conductor as a reference potential, a conversion unit configured to convert a differential signal that is a voltage difference between two electrical signals with noise removed by the noise removal circuit into a voltage signal that is a voltage with a reference potential corresponding to a potential of a second conductor, a first substrate on which the first conductor is disposed, a second substrate on which the second conductor is disposed, a substrate connector with flexibility that connects the first substrate and the second substrate, and an apparatus connector that connects the second substrate and a power supply apparatus, and the power supply apparatus supplies power to the conversion unit via the apparatus connector.

According to the aspect described above, the first substrate and the second substrate are connected via the substrate connector which is flexible. Thus, the flexibility relating to how to arrange the first sub substrate and the second sub substrate is high. Accordingly, the first substrate and the second substrate can be arranged so that the area of the installation surface of the communicator is reduced. When the area of the installation surface of the communicator is reduced, the area of the installation surface of the apparatus is also reduced.

In the communication device according to an aspect of the present disclosure, the power supply apparatus includes a first power supply conductor and a second power supply conductor, the first power supply conductor and the second power supply conductor are conductively connected to the first conductor and the second conductor, respectively, and the first power supply conductor and the second power supply conductor are connected via an inductor or a resistor.

According to the aspect described above, the first power supply conductor is conductively connected to the first conductor. Thus, the first power supply conductor and the first conductor are treated as one conductor. The second power supply conductor is conductively connected to the second conductor. Thus, the second power supply conductor and the second conductor are also treated as one conductor. The first power supply conductor and the second power supply conductor are connected via an inductor or a resistor. Accordingly, when noise enters the first power supply conductor, even when the potential of the first power supply conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second power supply conductor. In a similar manner, when noise enters the second power supply conductor, even when the potential of the second power supply conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the first power supply conductor.

In the communication device according to an aspect of the present disclosure, the power supply apparatus includes a first power supply conductor and a second power supply conductor, the first power supply conductor and the second power supply conductor are conductively connected to the first conductor and the second conductor, respectively, and the first power supply conductor and the second power supply conductor are connected via a second conducting wire.

According to the aspect described above, the first power supply conductor is conductively connected to the first conductor. Thus, the first power supply conductor and the first conductor are treated as one conductor. The second power supply conductor is conductively connected to the second conductor. Thus, the second power supply conductor and the second conductor are also treated as one conductor. The first power supply conductor and the second power supply conductor are connected via the second conducting wire. The second conducting wire has a resistance component. Accordingly, when noise enters the first conductor, even when the potential of the first conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second conductor. In a similar manner, when noise enters the second conductor, even when the potential of the second conductor fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the first conductor.

The communication device according to an aspect of the present disclosure further includes an electrically connecting element that implements an electrical connection, wherein the two conducting wires pass through the substrate connector, the substrate connector includes a connection conductor that conductively connects the first conductor and the second conductor, and the electrically connecting element is connected between the connection conductor and the second conductor or between the first conductor and the connection conductor.

According to the aspect described above, the connection conductor is conductively connected to one of the first power supply conductor or the second power supply conductor. The connection conductor is connected to the other one of the first conductor or the second conductor. This prevents the connection conductor from functioning as an antenna that converts the electromagnetic waves propagating through the air into a current. For example, when the connection conductor is insulated from the other one of the first conductor or the second conductor, there is a possibility that the connection conductor functions as an antenna that converts electromagnetic waves propagating through the air into a current. There is a possibility that the converted current acts as noise.

In the communication device according to an aspect of the present disclosure, the communicator transmits data included in a voltage signal converted by the conversion unit to the power supply apparatus via the apparatus connector.

According to the aspect described above, the power supply apparatus receives data from the communicator.

A specific example of a communication system according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to these examples and is defined by the scope of the claims, and all modifications that are equivalent to or within the scope of the claims are included.

First Embodiment

Communication System Configuration

FIG.1is a block diagram illustrating the configuration of a main portion of a communication system1according to the first embodiment. The communication system1is installed in a vehicle M. The communication system1includes a relay apparatus10, a relay11, a DC power supply12, and a plurality of ECUs (Electronic Control Units)13and14. The DC power supply12is a battery, for example. The relay apparatus10includes a power supply connector20and two bus connectors21. InFIG.1, the signal lines along which signals propagate are indicated by thick lines. Wiring lines other than these signal lines are indicated by thin lines.

A positive electrode and a negative electrode of the DC power supply12are separately connected to the power supply connector20of the relay apparatus10. The negative electrode of the DC power supply12is also connected to a ground. Grounding is implemented by connecting to the body of the vehicle M, for example. A communication bus Lb is connected to each one of the two bus connectors21of the relay apparatus10. The plurality of ECUs13are connected to the communication buses Lb. The relay11is connected to the relay apparatus10. The relay11is connected to each one of the plurality of ECUs14by communication lines Lc.

The DC power supply12supplies power to the relay apparatus10. The relay apparatus10is an ECU, for example. The relay apparatus10supplies power to the relay11. The relay apparatus10functions as a power supply apparatus. The relay apparatus10and the relay11executes various types of processing using the supplied power. The relay apparatus10and the ECUs13transmit differential signals including data via the communication buses Lb. Differential signal transmission corresponds to data transmission. The communication bus Lb includes two conducting wires. The differential signal is expressed by a voltage difference of two electrical signals that propagate via the two conducting wires. The differential signal transmitted via the communication bus Lb is received by all of the apparatuses connected to the communication bus Lb.

Each ECU13and14is connected to a non-illustrated actuator and sensor. Each ECU13and14obtain a detection result from the sensor. Each ECU13and14outputs an actuation signal to the actuator. The actuation signal indicates the operation of the actuator. When the actuator is input with an actuation signal, the operation indicated by the input actuation signal is executed. Each ECU13and14controls the operation of the actuator by outputting an actuation signal to the actuator. The actuator may be a door motor for locking or unlocking a door, a wiper motor for swinging the wipers, a lamp, or the like.

When the ECU13receives a differential signal via the communication bus Lb, the ECU13determines whether or not it is the transmission destination of the data included in the received differential signal. When the ECU13determines that it is the transmission destination of the data, the ECU13controls the operation of the actuator on the basis of the data of the received differential signal. For example, the ECU13transmits a differential signal including data indicating the detection result from a sensor via the communication bus Lb. The transmission destination of the data included in the differential signal is one of the ECUs13different from the transmission source or one of the ECUs14.

When the relay apparatus10receives a differential signal via the communication bus Lb, the relay apparatus10determines whether or not to relay the data transmission on the basis of the transmission destination of the data included in the differential signal received. When the relay apparatus10determines to relay the data transmission, the relay apparatus10executes at least one of two types of processing. The first processing is transmitting the differential signal via one of the communication buses Lb different from the communication bus Lb used to receive the differential signal. The second processing is transmitting a voltage signal including the data to the relay11. A voltage signal is a signal expressed by a voltage with the reference potential corresponding to the potential of a conductor. Voltage signal transmission also corresponds to data transmission.

When the relay11receives a voltage signal from the relay apparatus10, the relay11generates a differential signal including the data of the received voltage signal. The relay11transmits the generated differential signal to the ECUs14via the communication lines Lc. As with the communication bus Lb, the communication line Lc includes two conducting wires Wa and Wb (seeFIG.3). The differential signal is expressed by a voltage difference of two electrical signals that propagate via each of the two conducting wires Wa and Wb.

For example, the ECU14transmits a differential signal including data indicating the detection result from a sensor to the relay11via the communication line Lc. The transmission destination of the data included in the differential signal is one of the ECUs13or one of the ECUs14different from the transmission source. The relay11receives the differential signal. The relay11functions as a communicator. The apparatus including the relay apparatus10and the relay11functions as a communication device.

When the relay11receives a differential signal from the ECU14and the transmission destination of the data included in the received differential signal is one of the ECUs14different from the transmission source, the relay11transmits the differential signal including the data to the ECU14which is the transmission destination.

When the ECU14receives the differential signal via the communication line Lc, the ECU14controls the actuator on the basis of the data included in the received differential signal.

When the relay11receives a differential signal from the ECU14and the transmission destination of the data included in the received differential signal is one of the ECUs13, the relay11transmits a voltage signal including the data of the received differential signal to the relay apparatus10. When the relay apparatus10receives the voltage signal from the relay11, the relay apparatus10transmits the differential signal including the data of the received voltage signal to the ECUs13via the communication buses Lb.

In this manner, the relay apparatus10relays data communication between two of the ECUs13connected to two different communication buses Lb. The relay11relays data communication between two ECUs14. The relay apparatus10and the relay11relay communication between the ECUs13and14.

Communication via the communication buses Lb are performed according to the CAN (Controller Area Network) communication protocol, for example. Communication via the communication buses Lc is performed according to the Ethernet (registered trademark) communication protocol, for example.

In addition to the power supply connector20and the two bus connectors21, the relay apparatus10also includes a common mode choke coil22, a power supply circuit23, a communication circuit24, a first main conductor Gm1, and a second main conductor Gm2. The common mode choke coil22includes a first inductor22a, a second inductor22b, and a non-illustrated annular magnetic body. The first inductor22aand the second inductor22bare wound around the magnetic body. The potential of the first main conductor Gm1and the potential of the second main conductor Gm2function as grounds. The first main conductor Gm1functions as a first power supply conductor. The second main conductor Gm2functions as a second power supply conductor.

One end of the first inductor22aand one end of the second inductor22bare separately connected to the power supply connector20. The connection node between the second inductor22band the power supply connector20is connected to the first main conductor Gm1. The other end of the first inductor22ais connected to the power supply circuit23. The other end of the second inductor22band the power supply circuit23are separately connected to the second main conductor Gm2.

As described above, the second inductor22bis connected to the first main conductor Gm1and the second main conductor Gm2. The circuit element connecting the first main conductor Gm1and the second main conductor Gm2is not limited to the second inductor22band may be a resistor, for example. In this case, the power supply connector20is connected to the power supply circuit23bypassing the first inductor22a.

The power supply circuit23is further connected to the relay11and the communication circuit24. The communication circuit24is further separately connected to the relay11, the two bus connectors21, the first main conductor Gm1, and the second main conductor Gm2. The first main conductor Gm1and the second main conductor Gm2are separately connected to the relay11.

The voltage with the reference potential corresponding to the potential of the first main conductor Gm1is applied from the DC power supply12to one end of the first inductor22aand one end of the second inductor22bof the common mode choke coil22. The common mode choke coil22removes common mode noise from the applied voltage. Common mode noise is noise that is superpositioned in-phase in the two conducting wires connected to the ends of the first inductor22aand the second inductor22b.

The common mode choke coil22applies the voltage with common mode noise removed from the other end of the first inductor22ato the power supply circuit23. As described above, the other end of the second inductor22band the power supply circuit23are connected to the second main conductor Gm2. Thus, the voltage applied by the common mode choke coil22to the power supply circuit23is the voltage with the reference potential corresponding to the potential of the second main conductor Gm2.

The power supply circuit23decreases the voltage applied from the common mode choke coil22to a constant voltage such as 5V, 3.3 V, or the like. The power supply circuit23applies the constant voltage generated by decreasing the voltage to the relay11and the communication circuit24. Thus, the relay11and the communication circuit24are supplied with power. The reference potential of the constant voltage is the potential of the second main conductor Gm2.

When the communication circuit24receives a differential signal via the communication buses Lb, the communication circuit24removes the noise from the two electrical signals forming the received differential signal using the potential of the first main conductor Gm1as the reference potential. The communication circuit24converts the differential signal expressed by the voltage difference of the two electrical signals with the noise removed to a voltage signal with the reference potential corresponding to the potential of the second main conductor Gm2. The communication circuit24obtains the data included in the converted voltage signal.

The communication circuit24determines whether or not to relay the data transmission on the basis of the transmission destination of the obtained data. When the communication circuit24determines to relay the data transmission, the communication circuit24executes at least one of the two types of processing described above. As described above, the first processing is transmitting the differential signal via one of the communication buses Lb different from the communication bus Lb used to receive the differential signal. The second processing is transmitting a voltage signal including the data to the relay11.

In the first processing, the communication circuit24generates a differential signal including the obtained data and transmits the generated differential signal via the communication bus Lb different from the communication bus Lb used to receive the differential signal. In the second processing, the communication circuit24transmits the voltage signal indicating the obtained data to the relay11. As described above, when the relay11receives a voltage signal from the communication circuit24, the relay11generates a differential signal including the data of the received voltage signal. The relay11transmits the generated differential signal to the ECUs14.

As described above, the communication circuit24executes processing of the electrical signal with the potential of the first main conductor Gm1corresponding to the reference potential and processing of the electrical signal with the potential of the second main conductor Gm2corresponding to the reference potential.

As described above, the relay apparatus10includes the first main conductor Gm1and the second main conductor Gm2. When noise enters the first main conductor Gm1, even when the potential of the first main conductor Gm1fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second main conductor Gm2. In a similar manner, when noise enters the second main conductor Gm2, even when the potential of the second main conductor Gm2fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the first main conductor Gm1.

Note that the number of ECUs13connected to one communication bus Lb may be one. Also, the number of communication buses Lb connected to the relay apparatus10is not limited to two and may be one or three or more. The number of bus connectors21included in the relay apparatus10is adjusted to the same number as the number of communication buses Lb. When the number of communication buses Lb is 1, the relay apparatus10does not relay communication between two ECUs13.

FIG.2is a block diagram illustrating the configuration of a main portion of the relay11. In the example illustrated inFIG.2, the number of ECUs14is three. It is sufficient that the number of ECUs14connected to the relay11is one or more. Thus, the number of ECUs14is not limited to three. As withFIG.1, inFIG.2, the signal lines are indicated by thick lines. Wiring lines other than these signal lines are indicated by thin lines.

As illustrated inFIG.2, the relay11includes a communication line connector30, three signal processing circuits31, three conversion units32, a relay unit33, an apparatus connector34, a first sub conductor Gs1, and a second sub conductor Gs2. One end of each of the three communication lines Lc is separately connected to the communication line connector30. As described above, the communication line Lc includes the two conducting wires Wa and Wb. The other end of each of the communication lines Lc is connected to one of the ECUs14. The potential of the first sub conductor Gs1and the potential of the second sub conductor Gs2function as grounds.

The communication line connector30is separately connected to the three signal processing circuits31. The three signal processing circuits31are connected to the three conversion units32, respectively. The three conversion units32are further separately connected to the relay unit33. The three conversion units32and the relay unit33are further connected to the apparatus connector34. The apparatus connector34is further connected to the second sub conductor Gs2. The three signal processing circuits31are each separately connected to the first sub conductor Gs1and the second sub conductor Gs2. The three conversion units32and the relay unit33are further connected to the second sub conductor Gs2.

As described above, the relay apparatus10includes the power supply circuit23, the communication circuit24, the first main conductor Gm1, and the second main conductor Gm2. The communication circuit24is connected to the relay unit33via the apparatus connector34. The power supply circuit23is connected to the three conversion units32and the relay unit33via the apparatus connector34. The second main conductor Gm2is connected to the second sub conductor Gs2via the apparatus connector34. The first main conductor Gm1is connected to the first sub conductor Gs1bypassing the apparatus connector34.

Note that the number of the signal processing circuits31and the number of the conversion units32are the same as the number of the ECUs14. Thus, when the number of ECUs14changes, the number of the signal processing circuits31and the number of the conversion units32is adjusted to the same number as the number of ECUs14.

As described above, the power supply circuit23applies a constant voltage with the reference potential corresponding to the potential of the second main conductor Gm2to the relay11. The second main conductor Gm2is connected to the second sub conductor Gs2. The potential of the second main conductor Gm2is the same as the potential of the second sub conductor Gs2. The power supply circuit23applies a constant voltage with the reference potential corresponding to the potential of the second sub conductor Gs2to the conversion units32and the relay unit33. Thus, the conversion units32and the relay unit33are supplied with power.

As described above, the ECU14transmits a differential signal via the communication line Lc. In the relay11, the differential signal is input to the signal processing circuit31via the communication line Lc and the communication line connector30. The signal processing circuit31removes noise from the two electrical signals forming the differential signal input via the communication line Lc and the communication line connector30using the potential of the first sub conductor Gs1as the reference potential. In this example, the removed noise is electrostatic noise superpositioned on the signal when static electricity occurs, for example. When electrostatic noise is superpositioned on an electrical signal, the voltage of the electrical signal greatly increases temporarily. The first sub conductor Gs1functions as a first conductor. The signal processing circuit31functions as a noise removal circuits.

The signal processing circuit31removes the common mode noise from the differential signal formed from two electrical signals with noise removed. Common mode noise is noise that is superposition in-phase in the two conducting wires forming the communication line Lc. The signal processing circuit31removes noise from the two electrical signals forming the differential signal with the common mode noise removed using the potential of the second sub conductor Gs2as the reference potential. In this example, the removed noise is electrostatic noise, for example.

The signal processing circuit31outputs the differential signal expressed by the voltage difference of the two electrical signals with noise removed to the conversion unit32. In this manner, the conversion unit32receives the differential signal. The conversion unit32converts the received differential signal into a voltage signal expressed by a voltage with the reference potential corresponding to the potential of the second sub conductor Gs2. The second sub conductor Gs2functions as a second conductor. The conversion unit32outputs the converted voltage signal to the relay unit33. The relay unit33obtains the data included in the input voltage signal.

When the transmission destination of the obtained data is one of the ECUs13, the relay unit33generates a voltage signal included the obtained data. In this example, the reference potential of the voltage signal is the potential of the second sub conductor Gs2(second main conductor Gm2). The relay unit33transmits the generated voltage signal to the communication circuit24via the apparatus connector34. In this manner, the communication circuit24receives the data from the relay unit33.

When the transmission destination of the obtained data is one of the ECUs14, the relay unit33generates a voltage signal included the obtained data. In this example also, the reference potential of the voltage signal is the potential of the second sub conductor Gs2. The relay unit33outputs the generated voltage signal to the conversion unit32.

The communication circuit24transmits the voltage signal with the reference potential corresponding to the potential of the second main conductor Gm2(second sub conductor Gs2) to the relay unit33. When the relay unit33receives the voltage signal, the relay unit33obtains the data of the received voltage signal. The relay unit33generates a voltage signal including the obtained data and outputs the generated voltage signal to the conversion unit32. The relay unit33including an integrated circuit element, for example.

When the conversion unit32is input with the voltage signal from the relay unit33, the conversion unit32converts the input voltage signal into a differential signal. The conversion unit32transmits the converted differential signal to the ECU14via the signal processing circuit31and the communication line connector30.

As described above, at the relay11, processing of the electrical signal with the potential of the first sub conductor Gs1corresponding to the reference potential and processing of the electrical signal with the potential of the second sub conductor Gs2corresponding to the reference potential are executed.

The differential signal transmitted via the communication line Lc is, for example, a signal for communication compliant with the Ethernet communication protocol, a signal for communication using LVDS (Low Voltage Differential Signalling), or a signal for communication compliant with USB (Universal Serial Bus).

In communication compliant with the Ethernet communication protocol, communication using LVDS, or communication compliant with USB, signals are transmitted and received using a P2P (peer-to-peer) format. Thus, a large amount of data can be transmitted per unit time. When the P2P (peer-to-peer) format is used, the number of ECUs14is difficult to increase when the ECUs14are directly connected to the relay apparatus. However, the relay11is connected to the relay apparatus10. Thus, by substituting the current relay11with another relay11, the number of ECUs14can be easily increased or decreased.

Communication compliant with the CAN (Controller Area Network) communication protocol is an example of the communication for transmitting the differential signal. With this communication, the ECUs are connected to the communication bus. Thus, the number of ECUs can be easily increased or decreased. However, since the P2P format is not being used, only a small amount of data can be transmitted per unit time.

When the ECUs14are directly connected to the relay apparatus, the number of ECUs14is difficult to increase or decrease after the relay apparatus is manufactured. Consider a case in which a sensor is newly installed in a vehicle after the relay apparatus is manufactured. In this case, there is a possibility of it being necessary to transmit the detection result from the sensor from one of the ECUs14to the ECUs13or another ECU14. In this case, the number of ECUs14connected to the relay apparatus needs to be increased. However, since the ECUs14are directly connected to the relay apparatus, the relay apparatus needs to be newly manufactured.

However, in the communication system1, the ECU14for transmitting the sensor detection value can be easily added by substituting the current relay11with another relay11. Also, the relay11can be replaced. Accordingly, depending on the state of the vehicle M, the relay11can be attached to each one of the plurality of relay apparatuses10with different functions.

Signal Processing Circuit31Configuration

FIG.3is a circuit diagram of the signal processing circuit31. The signal processing circuit31includes two first suppressors40aand40b, the resistors41a,41b, and42, three capacitors43,44a, and44b, a common mode choke coil45, and two second suppressors46aand46b. The common mode choke coil45includes a first inductor45a, a second inductor45b, and an annular magnetic body. The first inductor45aand the second inductor45bare wound around the magnetic body.

As described above, the communication line Lc includes the two conducting wires Wa and Wb. The capacitor44aand the first inductor45aof the common mode choke coil45are disposed partway along the conducting wire Wa. The capacitor44ais disposed on the communication line connector30side of the first inductor45a. In a similar manner, the capacitor44band the second inductor45bof the common mode choke coil45are disposed partway along the conducting wire Wb. The capacitor44bis disposed on the communication line connector30side of the second inductor45b.

On the communication line connector30side of the capacitor44a, the first suppressor40aand one end of the resistor41aare connected to the conducting wire Wa. The connection point of the first suppressor40ais located closer to the communication line connector30than the connection point of the resistor41a. In a similar manner, on the communication line connector30side of the capacitor44b, the first suppressor40band one end of the resistor41bare connected to the conducting wire Wb. The connection point of the first suppressor40bis located closer to the communication line connector30than the connection point of the resistor41b.

The other end of the resistor41ais connected to the other end of the resistor41b. The connection node between the resistors41aand41bis connected to the resistor42and one end of the capacitor43. The first suppressors40aand40b, the resistor42, and the other end of the capacitor43are connected to the first sub conductor Gs1.

On the conversion unit32side of the first inductor45a, one end of the second suppressor46ais connected to the conducting wire Wa. In a similar manner, on the conversion unit32side of the second inductor45b, one end of the second suppressor46bis connected to the conducting wire Wb. The other ends of the second suppressors46aand46bare connected to the second sub conductor Gs2.

The first suppressors40aand40beach include a suppressor, a varistor, a capacitor, and the like. The first suppressors40aand40beach suppress the peak value of two electrical signals with the reference potential corresponding to the potential of the first sub conductor Gs1. As described above, there is a possibility that the peak value of the electrical signals greatly increases temporarily due to noise superposition. Electrostatic noise is removed from the electrical signals by suppressing the peak value. The two electrical signals propagate via each of the two conducting wires Wa and Wb. The first suppressors40aand40beach suppress the peak value of the two electrical signals forming the differential signal input from the communication line connector30.

The resistors41a,41b, and42and the capacitor43function as a termination circuit and suppress reflection of the differential signal input from the communication line connector30side. The capacitors44aand44beach remove the direct current component of the two electrical signals forming the differential signal input from the communication line connector30side. The capacitors44aand44boutput the differential signal expressed by the voltage difference of the two electrical signals with the direct current component removed to the common mode choke coil45.

The common mode choke coil45removes the common mode noise from the differential signal output by the capacitors44aand44band outputs a differential signal with the common mode noise removed to the conversion unit32side.

The second suppressors46aand46beach include a suppressor, a varistor, a capacitor, a Zener diode or diode clamp circuit, and the like. The second suppressors46aand46beach suppress the peak value of two electrical signals with the reference potential corresponding to the potential of the second sub conductor Gs2. In this manner, the noise is removed from the two electrical signals. The removed noise is electrostatic noise, for example. The two electrical signals propagate via each of the two conducting wires Wa and Wb. The second suppressors46aand46beach suppress the peak value of the two electrical signals forming the differential signal input from the common mode choke coil45. The differential signal formed by the two electrical signals with the peak value suppressed is input into the conversion unit32.

As described above, the conversion unit32transmits a differential signal via the communication line Lc. In this case, the second suppressors46aand46beach suppress the peak value of the two electrical signals forming the differential signal input from the conversion unit32. In this manner, the noise is removed from the two electrical signals. The differential signal formed by the two electrical signals with the peak value suppressed is input into the common mode choke coil45. The common mode choke coil45removes the common mode noise from the differential signal input from the conversion unit32side and outputs a differential signal with the common mode noise removed to the communication line connector30side.

The capacitors44aand44beach remove the direct current component of the two electrical signals forming the differential signal input from the conversion unit32side. The capacitors44aand44boutput the differential signal expressed by the voltage difference of the two electrical signals with the direct current component removed to the communication line connector30side. The first suppressors40aand40beach suppress the peak value of the two electrical signals forming the differential signal output by the capacitors44aand44b. In this manner, the noise is removed from the two electrical signals. The differential signal formed by the two electrical signals with the peak value suppressed is output to the ECU14via the communication line connector30.

As described above, the signal processing circuit31, using the potential of the first sub conductor Gs1as a reference potential, removes noise from the two electrical signals. The signal processing circuit31, using the potential of the second sub conductor Gs2as a reference potential, removes noise from the two electrical signals.

As described above, the relay11includes the first sub conductor Gs1and the second sub conductor Gs2. When noise enters the first sub conductor Gs1, even when the potential of the first sub conductor Gs1fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the second sub conductor Gs2. In a similar manner, when noise enters the second sub conductor Gs2, even when the potential of the second sub conductor Gs2fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the first sub conductor Gs1. The noise input to the first sub conductor Gs1is output to outside the relay apparatus10via the first main conductor Gm1and the power supply connector20. Note that the signal processing circuit31may have a configuration in which the two second suppressors46aand46bare not provided.

FIG.4is a plan view of the relay apparatus10and the relay11. In the example illustrated inFIG.4, the number of bus connectors21is two. As described above, the number of bus connectors21may be one or 3 or more. As illustrated inFIG.4, the relay apparatus10further includes a main substrate Bm. The first main conductor Gm1and the second main conductor Gm2are disposed inside the main substrate Bm. The first main conductor Gm1and the second main conductor Gm2each have a plate-like shape. The first main conductor Gm1and the second main conductor Gm2are arranged in the front-and-back direction of relay apparatus10. The main surface of the first main conductor Gm1and the main surface of the second main conductor Gm2face the main surface of the main substrate Bm. The main surface of the plate is a surface that has a wide width and is not an end surface.

The relay11, the power supply connector20, the two bus connectors21, the common mode choke coil22, the power supply circuit23, and the communication circuit24are disposed on the main surface of the main substrate Bm. As described above, the power supply connector20is connected to the first main conductor Gm1. The power supply circuit23is connected to the second main conductor Gm2. The relay11, the common mode choke coil22, and the communication circuit24are each connected to both the first main conductor Gm1and the second main conductor Gm2. The connection to the first main conductor Gm1or the second main conductor Gm2is implemented by providing a through hole in the main substrate Bm, for example.

FIG.5is an explanatory diagram of the external appearance of the relay11.

InFIG.5, the front surface, the back surface, and the side surface of the relay11are illustrated. The relay11includes a box35with one face open. The box35is a hollow rectangular parallelepiped. An opening35his provided in the front surface of the box35.

Two first projection portions36aand two second projection portions36bproject downward (outside the box35) from the lower surface of the box35. The two first projection portions36aare arranged side by side in the left-and-right direction. The two second projection portions36bare also arranged side by side in the left-and-right direction. The first projection portions36aand the second projection portions36bare disposed on the front side and the back side. The upper side inFIG.4corresponds to the front side of the relay11. The communication line connector30is inserted into the box35from the opening35h.

FIG.6is a cross-sectional view of the relay11. As illustrated inFIGS.5and6, the communication line connector30is a hollow rectangular parallelepiped with one face open. As illustrated inFIG.5, an opening30his provided in the front surface of the communication line connector30. For example, a cable including the plurality of communication lines Lc is inserted into the opening30hof the communication line connector30. In this manner, the plurality of communication lines Lc are connected to the communication line connector30. As illustrated inFIG.6, the back surface of the communication line connector30blocks the opening35hof the box35. A plurality of through holes25extending through in the up-and-down direction are provided in the main substrate Bm. The first projection portions36aand the second projection portions36bof the relay11are inserted into the through holes25of the main substrate Bm.

Thereafter, the first projection portions36aand the second projection portions36bare connected to the main substrate Bm via soldering. In this manner, the box35is fixed to the main substrate Bm. The box35and the first projection portions36ahave electrical conductivity. The first projection portions36a, for example, are conductively connected to the first main conductor Gm1disposed inside the main substrate Bm via soldering.

Inside the Relay11

FIG.7is an explanatory diagram of a plurality of members housed in the box35of the relay11. In the state illustrated inFIG.7, the plurality of members are removed from the box35and placed on a flat surface. As illustrated inFIGS.6and7, a first sub substrate Bs1and a second sub substrate Bs2, which have a rectangular shape, are housed in the box35of the relay11. As illustrated inFIG.6, the first sub substrate Bs1and the second sub substrate Bs2are disposed with a gap inbetween. The main surface of the first sub substrate Bs1faces the main surface of the second sub substrate Bs2.

As illustrated inFIGS.6and7, the end surface of the front side of the first sub substrate Bs1is connected to the back surface of the communication line connector30. In the relay11, the end surface of the back side of the first sub substrate Bs1and the end surface of the front side of the second sub substrate Bs2are connected by a substrate connector47which is rectangular and has flexibility. The substrate connector47is bent a plurality of times. The substrate connector47is a FPC (Flexible Printed Circuit), for example. On the first sub substrate Bs1and the second sub substrate Bs2, a plurality of conductive patterns are disposed on the main surface of the insulating plate. The substrate connector47conductively connects the conductive pattern of the first sub substrate Bs1to the conductive pattern of the second sub substrate Bs2.

A plurality of circuit elements forming the two first suppressors40aand40b, the three resistors41a,41b, and42, the three capacitors43,44a, and44b, and the common mode choke coil45are disposed on the main surface of the first sub substrate Bs1. The circuit elements function as a first circuit element. InFIGS.6and7, only the common mode choke coil45is illustrated. On the main surface of the second sub substrate Bs2, the plurality of circuit elements forming the two second suppressors46aand46b, the conversion unit32, and the relay unit33are disposed. The circuit elements function as a second circuit element. InFIGS.6and7, the second circuit element is omitted.

The first sub conductor Gs1is disposed inside the first sub substrate Bs1. The second sub conductor Gs2is disposed inside the second sub substrate Bs2. The first sub conductor Gs1and the second sub conductor Gs2function as the first conductor and the second conductor. The first sub substrate Bs1and the second sub substrate Bs2function as a first substrate and a second substrate.

The box35is conductively connected to the first sub conductor Gs1via a non-illustrated conductor. As described above, the first projection portions36aproject from the box35. Accordingly, the first projection portions36aare conductively connected to the box35. As a result, the first projection portions36aare conductively connected to the first sub conductor Gs1via the box35. As described above, when the box35of the relay11is fixed to the main substrate Bm via soldering, the first projection portions36aare conductively connected to the first main conductor Gm1. Accordingly, the first sub conductor Gs1is conductively connected to the first main conductor Gm1via the box35and the first projection portions36a. The first main conductor Gm1and the first sub conductor Gs1are treated as one conductor. Note that the box35is separated from the second sub conductor Gs2. The box35is not directly conductively connected to the second main conductor Gm2via a conductor.

FIG.8is another cross-sectional view of the relay11. The apparatus connector34of the relay11includes a conductive rod34pwith electrical conductivity. The conductive rod34pfunctions as a second conductive rod. The conductive rod34pis a so-called lead pin. As illustrated inFIGS.7and8, on the back side of the second sub substrate Bs2, an insertion hole48where the conductive rod34pis inserted is provided. The insertion hole48functions as a second insertion hole. The insertion hole48extends through in the up-and-down direction. As illustrated inFIG.7, a plurality of the insertion holes48are arranged side by side in the left-and-right direction. In the example inFIG.7, six insertion holes48are provided. InFIG.7, to prevent complexity in the diagram, only one insertion hole48is given a reference sign.

A through hole35iextending through in the up-and-down direction is provided in the lower surface of the box35. An insertion hole26where the conductive rod34pis inserted is provided in the main surface of the main substrate Bm of the relay apparatus10. The conductive rod34ppasses through the through hole35i. In this state, the conductive rod34pis inserted in the two insertion holes26and48. Inside the insertion hole26, the conductive rod34pis connected to the main substrate Bm via soldering. Inside the insertion hole48, the conductive rod34pis connected to the second sub substrate Bs2via soldering. Thus, the conductive rod34pof the apparatus connector34connects the second sub substrate Bs2and the main substrate Bm of the relay apparatus10. The conductive rod34pis conductively connected to the main substrate Bm and the conductive pattern provided on second sub substrate Bs2via soldering.

Inside the through hole35i, an insulator is embedded between the conductive rod34pand the box35. The box35is separated from the conductive rod34pand not conductively connected to the conductive rod34p.

The apparatus connector34includes at least three of the conductive rods34p. As illustrated inFIG.2, the first conductive rod34pconnects the communication circuit24of the relay apparatus10and the relay unit33of the relay11. The second conductive rod34pconnects the power supply circuit23of the relay apparatus10and the conversion unit32and relay unit33of the relay11. Accordingly, power is supplied from the power supply circuit23to the conversion unit32and the relay unit33via the conductive rod34pof the apparatus connector34. The third conductive rod34pconnects the second main conductor Gm2of the relay apparatus10and the second sub conductor Gs2of the relay11. Accordingly, the second main conductor Gm2is conductively connected to the second sub conductor Gs2. Thus, the second main conductor Gm2and the second sub conductor Gs2are treated as one conductor.

In the relay11, the first sub substrate Bs1and the second sub substrate Bs2are connected via the substrate connector47which is flexible. Thus, the flexibility relating to how to arrange the first sub substrate Bs1and the second sub substrate Bs2is high. Accordingly, the first sub substrate Bs1and the second sub substrate Bs2can be arranged so that the area of the installation surface of the relay11is reduced. Specifically, by making one surface of the first sub substrate Bs1and one surface of the second sub substrate Bs2face one another, the area of the installation surface of the relay11is reduced. Since the area of the installation surface of the relay11is reduced, the installation surface of the communication device including the relay apparatus10and the relay11is reduced.

Second Embodiment

In the first embodiment, the configuration of the apparatus connector34of the relay11is not limited to a configuration including the conductive rod34p. Hereinafter, the differences between the second embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

Inside the Relay11

FIG.9is a cross-sectional view of the relay11according to the second embodiment. In the second embodiment, the apparatus connector34of the relay11is a rectangular parallelepiped. The upper surface of the apparatus connector34is installed on the lower surface of the second sub substrate Bs2. A through hole35jextending through in the up-and-down direction is provided in the lower surface of the box35. The apparatus connector34is inserted into the through hole35jand exposed outside the box35. A recess portion recessed upward is provided in the lower surface of the apparatus connector34.

In the relay apparatus10, a rectangular parallelepiped connector27connected to the apparatus connector34is installed on the upper main surface of the main substrate Bm. A projection portion projecting upward is provided on the upper surface of the connector27. The projection portion of the connector27is inserted into the recess portion of the apparatus connector34. In this manner, the apparatus connector34is connected to the connector27.

The apparatus connector34is conductively connected to the conductive pattern provided on the second sub substrate Bs2. The connector27is conductively connected to the conductive pattern provided on the main substrate Bm. Thus, the apparatus connector34connects the second sub substrate Bs2and the main substrate Bm of the relay apparatus10by connecting to the connector27. The power supply circuit23of the relay apparatus10supplies power to the conversion unit32and the relay unit33via the apparatus connector34. The relay11and the communication device according to the second embodiment achieve an effect similar to that of the first embodiment.

Third Embodiment

In the second embodiment, the shape of the apparatus connector34is not limited to a rectangular parallelepiped. Hereinafter, the differences between the third embodiment and the second embodiment will be described. Configurations that are not described below are the same as in the second embodiment. Thus, configurations shared with the second embodiment are given the same reference sign as in the second embodiment and description thereof will be omitted.

Inside the Relay11

FIG.10is an explanatory diagram of a plurality of members housed in the box35of the relay11according to the third embodiment.FIG.11is a cross-sectional view of the relay11. As illustrated inFIGS.10and11, in the relay11, the plate-like apparatus connector34projects backward from the end surface on the back side of the second sub substrate Bs2. The apparatus connector34is an edge connector. As illustrated inFIG.10, a plurality of conductive patterns are disposed on the main surface of the apparatus connector34.

In the third embodiment, the through hole35jis provided in the back surface of the box35. The through hole35jextends through in the left-and-right direction. The apparatus connector34is inserted into the through hole35jand exposed on the back side of the box35.

In the connector27, the insertion portion where the apparatus connector34is inserted and the installation portion installed on the main surface of the main substrate Bm of the relay apparatus10are connected via a connection line. A recess portion recessed inward is provided in one surface of the insertion portion. The apparatus connector34is inserted into the recess portion of the insertion portion of the connector27. In this manner, the apparatus connector34is connected to the connector27.

The apparatus connector34is conductively connected to the conductive pattern provided on the second sub substrate Bs2. The connector27is conductively connected to the conductive pattern provided on the main substrate Bm. Thus, the apparatus connector34connects the second sub substrate Bs2and the main substrate Bm of the relay apparatus10by connecting to the connector27. The power supply circuit23of the relay apparatus10supplies power to the conversion unit32and the relay unit33via the apparatus connector34. The relay11and the communication device according to the third embodiment achieve an effect similar to that of the second embodiment.

Fourth Embodiment

In the fourth embodiment, the apparatus connector34is not limited to an edge connector. Hereinafter, the differences between the fourth embodiment and the third embodiment will be described. Configurations that are not described below are the same as in the third embodiment. Thus, configurations shared with the third embodiment are given the same reference sign as in the third embodiment and description thereof will be omitted.

Inside the Relay11

FIG.12is a cross-sectional view of the relay11according to the fourth embodiment. As illustrated inFIG.12, in the relay11, the plate-like apparatus connector34projects backward from the end surface on the back side of the second sub substrate Bs2. The apparatus connector34has flexibility. The apparatus connector34is an FPC, for example. One end portion of the apparatus connector34is installed on the second sub substrate Bs2. In the fifth embodiment, the apparatus connector34is inserted into the through hole35jand exposed on the back side of the box35. The other end portion of the apparatus connector34is connected to a plate-like terminal.

In the relay apparatus10, the rectangular parallelepiped connector27connected to the apparatus connector34is installed on the upper main surface of the main substrate Bm. A recess portion recessed downward is provided in the upper surface of the connector27. The terminal of the apparatus connector34is inserted into the recess portion of the connector27. In this manner, the apparatus connector34is connected to the connector27. Since the apparatus connector34has flexibility, the connection between the connector27and the apparatus connector34can be easily implemented.

The apparatus connector34is conductively connected to the conductive pattern provided on the second sub substrate Bs2. The connector27is conductively connected to the conductive pattern provided on the main substrate Bm. Thus, the apparatus connector34connects the second sub substrate Bs2and the main substrate Bm of the relay apparatus10by connecting to the connector27. The power supply circuit23of the relay apparatus10supplies power to the conversion unit32and the relay unit33via the apparatus connector34. The relay11and the communication device according to the fourth embodiment achieve an effect similar to that of the third embodiment.

Fifth Embodiment

In the second embodiment, the arrangement of the first sub substrate Bs1and the second sub substrate Bs2is not limited to the arrangement in which the main surface of the first sub substrate Bs1and the main surface of the second sub substrate Bs2face one another. Hereinafter, the differences between the fifth embodiment and the second embodiment will be described. Configurations that are not described below are the same as in the second embodiment. Thus, configurations shared with the second embodiment are given the same reference sign as in the second embodiment and description thereof will be omitted.

Inside the Relay11

FIG.13is a cross-sectional view of the relay11according to the fifth embodiment. In the fifth embodiment, the opening35hof the box35is blocked by the front surface of the communication line connector30. As in the second embodiment, the opening30his provided in the front surface of the communication line connector30. One main surface of the first sub substrate Bs1is installed on the back surface of the communication line connector30. A plurality of circuit elements (the first circuit element) are disposed on the other main surface of the first sub substrate Bs1.

As in the second embodiment, the second sub substrate Bs2is disposed with the two main surfaces orientated upward and downward. Aplurality of circuit elements (the second circuit element) are disposed on the upper main surface of the second sub substrate Bs2. Thus, the main surface of the first sub substrate Bs1and the main surface of the second sub substrate Bs2are perpendicular to one another.

Perpendicular herein means substantially perpendicular. Thus, the angle formed by the main surface of the first sub substrate Bs1and the main surface of the second sub substrate Bs2is not limited to 90 degrees. When an offset from 90 degrees is within design tolerance, the main surfaces of the first sub substrate Bs1and the second sub substrate Bs2are perpendicular.

In the fifth embodiment, the substrate connector47connects the upper end surface of the first sub substrate Bs1and the end surface of the front side of the second sub substrate Bs2.

The relay11according to the fifth embodiment achieves similar effects to those achieved by the relay11according to the second embodiment except for those effects obtained by arranging one surface of the first sub substrate Bs1facing one surface of the second sub substrate Bs2. In the relay11according to the fifth embodiment, by arranging the first sub substrate Bs1and the second sub substrate Bs2so that the main surface of the first sub substrate Bs1and the main surface of the second sub substrate Bs2are perpendicular to one another, the installation surface of the relay11is reduced.

Sixth Embodiment

In the fifth embodiment, the configuration of the apparatus connector34may be similar to the configuration of the fourth embodiment. Hereinafter, the differences between the sixth embodiment and the fifth embodiment will be described. Configurations that are not described below are the same as in the fifth embodiment. Thus, configurations shared with the fifth embodiment are given the same reference sign as in the fifth embodiment and description thereof will be omitted.

FIG.14is a cross-sectional view of the relay11according to the sixth embodiment. As in the fourth embodiment, the apparatus connector34has a plate-like shape and flexibility. The apparatus connector34projects backward from the end surface on the back side of the second sub substrate Bs2. The apparatus connector34is an FPC, for example. One end portion of the apparatus connector34is installed on the second sub substrate Bs2. In the fifth embodiment, the apparatus connector34is inserted into the through hole35jand exposed on the back side of the box35. The other end portion of the apparatus connector34is connected to a plate-like terminal.

The connector27of the relay apparatus10is configured as in the fourth embodiment. The plate portion of the apparatus connector34is inserted into the recess portion of the connector27. In this manner, the apparatus connector34is connected to the connector27. Since the apparatus connector34has flexibility, the connection between the connector27and the apparatus connector34can be easily implemented.

The apparatus connector34is conductively connected to the conductive pattern provided on the second sub substrate Bs2. The connector27is conductively connected to the conductive pattern provided on the main substrate Bm. Thus, the apparatus connector34connects the second sub substrate Bs2and the main substrate Bm of the relay apparatus10by connecting to the connector27. The power supply circuit23of the relay apparatus10supplies power to the conversion unit32and the relay unit33via the apparatus connector34. The relay11and the communication device according to the sixth embodiment achieve an effect similar to that of the fifth embodiment.

Note that in the sixth embodiment, the configuration of the apparatus connector34may be a configuration including the conductive rod34pas in the first embodiment. Also, the apparatus connector34may be an edge connector as in the third embodiment. In this case, the connector27is configured as in the third embodiment.

Seventh Embodiment

In the first embodiment, the first main conductor Gm1of the relay apparatus10and the first sub conductor Gs1of the relay11are conductively connected by the box35and the first projection portions36a. However, the conductive connection between the first main conductor Gm1and the first sub conductor Gs1may be implemented by another method. Hereinafter, the differences between the seventh embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.15is an explanatory diagram of a plurality of members housed in the box35of the relay11according to the seventh embodiment.FIG.16is a cross-sectional view of the relay11. InFIG.15, as inFIG.7, only one insertion hole48is given a reference sign. As illustrated inFIGS.15and16, on the front side of the first sub substrate Bs1, an insertion hole49extending through in the up-and-down direction is provided. As illustrated inFIG.16, in the seventh embodiment, the relay11includes a conductive rod37with electrical conductivity. The conductive rod37is a so-called lead pin. The conductive rod37is inserted into the insertion hole49.

A through hole35kextending through in the up-and-down direction is provided in the lower surface of the box35. An insertion hole28where the conductive rod37is inserted is provided in the main surface of the main substrate Bm of the relay apparatus10. The conductive rod37passes through the through hole35k. In this state, the conductive rod37is inserted in the two insertion holes28and49. Inside the insertion hole28, the conductive rod37is connected to the main substrate Bm via soldering. The conductive rod37, for example, is conductively connected to the first main conductor Gm1provided on the main substrate Bm via soldering.

Inside the insertion hole49, the conductive rod37is connected to the first sub substrate Bs1via soldering. The conductive rod37, for example, is conductively connected to the first sub conductor Gs1provided on the first sub substrate Bs1via soldering. As described above, in the seventh embodiment, the first main conductor Gm1and the first sub conductor Gs1are conductively connected via the conductive rod37. The relay11and the communication device according to the seventh embodiment achieve an effect similar to that of the first embodiment.

In the seventh embodiment, the first main conductor Gm1and the first sub conductor Gs1may not be conductively connected by the box35and the first projection portions36a. The box35may be an insulator. Also, the box35may be made of resin, for example. As in the seventh embodiment, in the relay11according to the second to sixth embodiments, the conductive rod37may be used to implement the conductive connection between the first main conductor Gm1and the first sub conductor Gs1. In the configuration of the fifth and sixth embodiments, the conductive rod37has an L shape.

Eighth Embodiment

In the fourth embodiment, the communication line connector30is not limited to a hollow rectangular parallelepiped with one face open. Hereinafter, the differences between the eighth embodiment and the fourth embodiment will be described. Configurations that are not described below are the same as in the fourth embodiment. Thus, configurations shared with the fourth embodiment are given the same reference sign as in the fourth embodiment and description thereof will be omitted.

Inside the Relay11

FIG.17is an explanatory diagram of a plurality of members housed in the box35of the relay11according to the eighth embodiment.FIG.18is a cross-sectional view of the relay11. As illustrated inFIGS.17and18, in the relay11, the plate-like communication line connector30projects forward from the end surface on the front side of the first sub substrate Bs1. The communication line connector30is an edge connector. As illustrated inFIG.17, a plurality of conductive patterns are disposed on the main surface of the communication line connector30.

As illustrated inFIG.18, the communication line connector30is inserted into the opening35hof the box35and exposed on the front side of the box35. For example, the plurality of communication lines Lc are housed inside a cable. The cable is provided with a recess portion. The communication line connector30is inserted into the recess portion of the cable. In this manner, the communication line connector30is connected to the plurality of communication lines Lc. The relay11and the communication device according to the eighth embodiment achieve an effect similar to that of the fourth embodiment.

In the relay11according to the first to third and the fifth to seventh embodiment, the communication line connector30may be an edge connector as in the fourth embodiment. When the main surface of the first sub substrate Bs1and the main surface of the second sub substrate Bs2are perpendicular to one another, the communication line connector30projects to the front side from the main surface on the front side of the first sub substrate Bs1.

Ninth Embodiment

In the first embodiment, the box35of the relay11is fixed to the main surface of the main substrate Bm of the relay apparatus10via soldering. However, the method of fixing the box35is not limited to a method using soldering. Hereinafter, the differences between the ninth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.19is a front view of the relay11according to the ninth embodiment. The relay11according to the ninth embodiment includes two first projection portions38instead of the two first projection portions36a. As illustrated inFIG.19, one of the first projection portions38projects to the left from the left surface of the box35. The other first projection portion38projects to the right from the right surface of the box35. A through hole38hextending through in the up-and-down direction is provided in each of the first projection portions38.

Two screw holes29are provided in the upper main surface of the main substrate Bm of the relay apparatus10. Two screws50are passed through the two through holes38h. In this state, the two screws50are inserted into the two screw holes29. Then, the two screws50are tightened. By tightening the two screws50, the box35is fixed to the main surface of the main substrate Bm. When the box35is fixed, the top portions of the screws50come into contact with the first projection portions38.

The screws50and the first projection portions38have electrical conductivity. As described in the first embodiment, the box35has electrical conductivity and is conductively connected to the first sub conductor Gs1. Since the first projection portions38are provided on the box35, the box35is conductively connected to the first projection portions38. Thus, the first projection portions38are conductively connected to the first sub conductor Gs1via the box35. When the box35is fixed, the first projection portions38are in contact with the screws50, and thus the screws50are conductively connected to the first projection portions38. The screws50are conductively connected to the first main conductor Gm1inside the main substrate Bm. As a result, the first sub conductor Gs1is conductively connected to the first main conductor Gm1via the box35, the first projection portions38, and the screws50.

The relay11and the communication device according to the ninth embodiment achieve an effect similar to that of the first embodiment. Note that in the ninth embodiment, instead of the second projection portions36b, second projection portions configured in a similar manner to the first projection portions38may be used. In this case also, screws are passed through the through holes of the second projection portions, and the screws are inserted into the screw holes in the main substrate Bm. Then, the screws are tightened.

Also, as in the ninth embodiment, the relay11according to the second to eighth embodiment may include the first projection portions38instead of the first projection portions36a. In this case also, as in the ninth embodiment, the box35is fixed to the upper surface of the main substrate Bm using the screws50.

Tenth Embodiment

In the first embodiment, the method of conductively connecting the second main conductor Gm2and the second sub conductor Gs2is not limited to a method using the conductive rod34p. Hereinafter, the differences between the tenth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.20is a side view of the relay11according to the tenth embodiment. As illustrated inFIG.20, the box35includes a first conductive portion35a, a second conductive portion35b, and a connection portion35c. The first conductive portion35aand the second conductive portion35bare disposed on the front side and the back side. The connection portion35cconnects the first conductive portion35aand the second conductive portion35b. In the tenth embodiment, the shape of the box35is as in the first embodiment.

The first conductive portion35aand the second conductive portion35bhave electrical conductivity. The connection portion35chas insulating properties. The first conductive portion35ais separated from the second conductive portion35bby the connection portion35c. The two first projection portions36aproject downward from the lower surface of the first conductive portion35a. The two second projection portions36bproject downward from the lower surface of the second conductive portion35b. The second projection portions36bhave electrical conductivity in a similar manner to the first projection portions36a.

The first conductive portion35aof the box35is conductively connected to the first sub conductor Gs1via a non-illustrated conductor. The first projection portions36aare conductively connected to the first conductive portion35a. When the box35is fixed to the main substrate Bm of the relay apparatus10via soldering, the first projection portions36aare conductively connected to the first main conductor Gm1. Accordingly, the first sub conductor Gs1is conductively connected to the first main conductor Gm1via the first conductive portion35aand the first projection portions36a.

In a similar manner, the second conductive portion35bof the box35is conductively connected to the second sub conductor Gs2via a non-illustrated conductor. The second projection portions36bare conductively connected to the second conductive portion35b. When the box35is fixed to the main substrate Bm of the relay apparatus10via soldering, the second projection portions36bare conductively connected to the second main conductor Gm2. Accordingly, the second sub conductor Gs2is conductively connected to the second main conductor Gm2via the second conductive portion35band the second projection portions36b.

As described above, the first projection portions36aand the second projection portions36bcan be conductively connected to the first main conductor Gm1and the second main conductor Gm2. Note that in the relay11according to the tenth embodiment, the conductive rod34pconnecting the second main conductor Gm2and the second sub conductor Gs2is not required.

The relay11and the communication device according to the tenth embodiment achieve an effect similar to that of the first embodiment. Note that in the second to ninth embodiment, the box35may be configured as in the tenth embodiment. In the second to eighth embodiment, the first projection portions36aand the second projection portions36bare provided as in the first embodiment. In the ninth embodiment, the first projection portions38project from the first conductive portion35a. The second projection portions of the ninth embodiment have electrical conductivity and project from the second conductive portion35b. In this case, screws with electrical conductivity are passed through the through holes of the second projection portions. The second sub conductor Gs2is conductively connected to the second main conductor Gm2via the second conductive portion35b, the second projection portions and the screws.

Eleventh Embodiment

In the first embodiment, the second inductor22bor a resistor connects the first main conductor Gm1and the second main conductor Gm2. However, a member other than the second inductor22bor a resistor may connect the first main conductor Gm1and the second main conductor Gm2. Hereinafter, the differences between the eleventh embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.21is a block diagram illustrating the configuration of a main portion of the relay apparatus10. The relay apparatus10according to the eleventh embodiment has the same components of the relay apparatus10according to the first embodiment except the common mode choke coil22is not provided. The relay apparatus10according to the eleventh embodiment further includes a second conducting wire60.

The power supply circuit23is directly connected to the power supply connector20. One end of the second conducting wire60is connected to the power supply connector20and the first main conductor Gm1. The other end of the second conducting wire60is connected to the second main conductor Gm2. In this manner, the first main conductor Gm1and the second main conductor Gm2are connected via the second conducting wire60.

The current flows from the positive electrode of the DC power supply12in order from the power supply circuit23, the second main conductor Gm2, and the second conducting wire60and returns to the negative electrode of the DC power supply12. The DC power supply12applies a voltage with the reference potential corresponding to the potential of the second main conductor Gm2to the power supply circuit23. The power supply circuit23decreases the voltage applied from the DC power supply12to a constant voltage such as 5V, 3.3 V, or the like. As in the first embodiment, the power supply circuit23applies the constant voltage generated by decreasing the voltage to the relay11and the communication circuit24. Thus, the relay11and the communication circuit24are supplied with power. The reference potential of the constant voltage is the potential of the second main conductor Gm2. As in the first embodiment, the noise that enters the first sub conductor Gs1of the relay11is output to outside the relay apparatus10via the first main conductor Gm1and the power supply connector20.

FIG.22is an explanatory diagram of the arrangement of the second conducting wire60. As illustrated inFIG.22, the second conducting wire60is disposed on the main surface of the main substrate Bm. One end of the second conducting wire60is located on the upper side of the first main conductor Gm1and is connected to one point of the first main conductor Gm1. The other end of the second conducting wire60is located on the upper side of the second main conductor Gm2and is connected to one point of the second main conductor Gm2.

The second conducting wire60includes a resistance component. Since the second conducting wire60has a linear shape, the cross-sectional area of the second conducting wire60is small. Thus, the resistance value of the resistance component of the second conducting wire60is large. This makes noise difficult to pass through the second conducting wire60. When noise enters the first main conductor Gm1, even when the potential of the first main conductor Gm1fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second main conductor Gm2. In a similar manner, when noise enters the second main conductor Gm2, even when the potential of the second main conductor Gm2fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the first main conductor Gm1.

The communication device according to the eleventh embodiment achieves an effect similar to that of the first embodiment. As described in the first embodiment, the communication device includes the relay apparatus10and the relay11. Note that the configuration of the relay11is not limited to the configuration in the first embodiment. The relay11of the eleventh embodiment may be configured in a similar manner to one of the relays11in the second to tenth embodiment.

Twelfth Embodiment

In the first embodiment, the negative electrode of the DC power supply12is connected to the first main conductor Gm1via the power supply connector20.

However, the negative electrode of the DC power supply12may not be connected to the first main conductor Gm1. Hereinafter, the differences between the twelfth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.23is a block diagram illustrating the configuration of a main portion of the relay apparatus10according to the twelfth embodiment. The relay apparatus10according to the twelfth embodiment has the same components of the relay apparatus10according to the first embodiment except the common mode choke coil22is not provided. The relay apparatus10according to the twelfth embodiment further includes a connecting component61.

The power supply circuit23is directly connected to the power supply connector20. The power supply connector20is further connected to the second main conductor Gm2. The power supply connector20is not connected to the first main conductor Gm1. The connecting component61is an inductor, a resistor, a conducting wire, or the like. The conducting wire includes a resistance component. One end of the connecting component61is connected to the first main conductor Gm1. The other end of the connecting component61is connected to the second main conductor Gm2. Thus, the first main conductor Gm1and the second main conductor Gm2are connected via the connecting component61.

As described above, the connecting component61is an inductor, a resistor, a conducting wire, or the like. Thus, as in the first or eleventh embodiment, when noise enters the first main conductor Gm1, even when the potential of the first main conductor Gm1fluctuates, there is little effect on the voltage or electrical signal with the reference potential corresponding to the potential of the second main conductor Gm2. In a similar manner, when noise enters the second main conductor Gm2, even when the potential of the second main conductor Gm2fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the first main conductor Gm1.

FIG.24is an explanatory diagram of the arrangement of the connecting component61. As illustrated inFIG.24, the connecting component61is disposed on the main surface of the main substrate Bm. One end of the connecting component61is located on the upper side of the first main conductor Gm1and is connected to one point of the first main conductor Gm1. The other end of the connecting component61is located on the upper side of the second main conductor Gm2and is connected to one point of the second main conductor Gm2.

As illustrated inFIG.23, in the relay apparatus10, the first main conductor Gm1is not connected to the power supply connector20. Thus, the first main conductor Gm1does not need to be disposed near the power supply connector20. Accordingly, as illustrated inFIG.24, as the first main conductor Gm1, a plate-like conductor with a small area for the main surface can be used. When a plate-like conductor with a small area for the main surface is used as the first main conductor Gm1, as the second main conductor Gm2, a plate-like conductor with a large area for the main surface can be used. In this case, since the resistance value of the second main conductor Gm2is low, the potential of the second main conductor Gm2is stable.

The communication device according to the twelfth embodiment achieves an effect similar to that of the first embodiment. Note that the configuration of the relay11is not limited to the configuration in the first embodiment. The relay11of the twelfth embodiment may be configured in a similar manner to one of the relays11in the second to tenth embodiment.

Thirteenth Embodiment

In the first embodiment, the first sub conductor Gs1of the relay11is connected to the first main conductor Gm1of the relay apparatus10. However, the first sub conductor Gs1may not be connected to the first main conductor Gm1. Hereinafter, the differences between the thirteenth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.25is a partial cross-sectional view of the substrate connector47according to the thirteenth embodiment. InFIG.25, the substrate connector47, the first sub substrate Bs1, and the second sub substrate Bs2are illustrated in a state of being disposed on a flat surface. In the box35, the substrate connector47is bent a plurality of times. As described in the description of the first embodiment, the relay11includes the substrate connector47which has a rectangular shape and flexibility. The substrate connector47connects one end surface of the first sub conductor Gs1and one end surface of the second sub conductor Gs2. One end portion of the substrate connector47is embedded in the first sub substrate Bs1. The other end portion of the substrate connector47is embedded in the second sub substrate Bs2.

FIG.26is a cross-sectional view of the substrate connector47taken along line A-A inFIG.25. In the example illustrated inFIG.26, the number of ECUs14is three. When the number of ECUs14is three, inside the relay11, three communication lines Lc are disposed. Each communication line Lc includes the two conducting wires Wa and Wb along which differential signals propagate. The two conducting wires Wa and Wb included in each communication line Lc pass through the inside of the substrate connector47.

In the substrate connector47, the two conducting wires Wa and Wb included in each communication line Lc are embedded inside an insulator47i. In the left-and-right direction, the conducting wires Wa and Wb are alternately arranged. The conducting wires Wa and Wb are disposed with a gap inbetween. Inside the insulator47i, a connection conductor47gwith a rectangular plate-like shape is embedded. The connection conductor47gis disposed on the lower side of the two conducting wires Wa and Wb included in each communication line Lc. The two conducting wires Wa and Wb included in each communication line Lc each face the common upper main surface of the connection conductor47gwith a gap therebetween. As described in the description of the first embodiment, regarding the plate, the main surface is a surface that has a wide width and is not an end surface.

FIG.27is a block diagram illustrating the configuration of a main portion of the relay11.FIG.28is a circuit diagram of the signal processing circuit31. As illustrated inFIGS.27and28, one end portion of the connection conductor47gincluded in the substrate connector47is connected to the first sub conductor Gs1and conductively connected to the first sub conductor Gs1. In the substrate connector47, by disposing the connection conductor47g, the characteristic impedance of the two conducting wires Wa and Wb included in each communication line Lc is adjusted to a constant value of 100Ω, 120Ω, or the like. As described in the description of the first embodiment, electrical signals propagate via the conducting wires Wa and Wb.

The relay11includes a conductor connecting element70. The conductor connecting element70is an inductor, a resistor, a conducting wire, or the like. The conducting wire includes a resistance component. The conductor connecting element70connects the other end portion of the connection conductor47gand the second sub conductor Gs2. As described above, one end portion of the connection conductor47gis connected to the first sub conductor Gs1. Thus, the conductor connecting element70is connected between the first sub conductor Gs1and the second sub conductor Gs2.

FIG.29is an explanatory diagram of the arrangement of the conductor connecting element70. As illustrated inFIG.29, one end portion of the connection conductor47gis located inside the first sub substrate Bs1. The other end portion of the connection conductor47gis located inside the second sub substrate Bs2. The conductor connecting element70is disposed on the main surface of the first sub substrate Bs1. One end of the conductor connecting element70is located on the upper side of the first sub conductor Gs1. One end of the conductor connecting element70is connected to the first sub conductor Gs1using a through hole, for example. The other end of the conductor connecting element70is located on the upper side of the connection conductor47g. The other end of the conductor connecting element70is connected to the connection conductor47gusing a through hole, for example.

In the thirteenth embodiment, the first sub conductor Gs1is not conductively connected to the first main conductor Gm1. In the first embodiment, the first sub conductor Gs1is conductively connected to the first main conductor Gm1via the box35and the first projection portion37a. In the thirteenth embodiment, in a first example, one or both of the box35and the first projection portion36ahave insulating properties. In a second example, connection between the first projection portion37aand the first main conductor Gm1is not implemented.

The conductor connecting element70is connected between the first sub conductor Gs1and the second sub conductor Gs2. Thus, when noise enters the first sub conductor Gs1, even when the potential of the first sub conductor Gs1fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the second sub conductor Gs2. In a similar manner, when noise enters the second sub conductor Gs2, even when the potential of the second sub conductor Gs2fluctuates, there is little effect on the voltage or signal with the reference potential corresponding to the potential of the first sub conductor Gs1.

The relay11and the communication device according to the thirteenth embodiment achieve an effect similar to that of the first embodiment. Note that in the thirteenth embodiment, the other end portion of the connection conductor47gincluded in the substrate connector47may be connected to the second sub conductor Gs2and may be conductively connected to the second sub conductor Gs2. In this case, one end portion of the connection conductor47gis not conductively connected to the first sub conductor Gs1. When the other end portion of the connection conductor47gis conductively connected to the second sub conductor Gs2, the conductor connecting element70connects one end portion of the connection conductor47gand the first sub conductor Gs1. The conductor connecting element70is connected between the first sub conductor Gs1and the second sub conductor Gs2.

Also, in the thirteenth embodiment, as in the first embodiment, the first sub conductor Gs1may be conductively connected to the first main conductor Gm1. The apparatus connector34of the relay11may be configured as in one of the second or sixth embodiment. The shape of the apparatus connector34may be similar to the shape in one of the third or fourth embodiment. The first sub substrate Bs1and the second sub substrate Bs2may be disposed as in the fifth embodiment. When the first sub conductor Gs1is conductively connected to the first main conductor Gm1, the conductive connection between the first main conductor Gm1and the first sub conductor Gs1may be implemented as in the seventh embodiment.

The shape of the communication line connector30may be similar to the shape in the eighth embodiment. As in the ninth embodiment, the box35of the relay11may be fixed to the main surface of the main substrate Bm of the relay apparatus10. The conductive connection between the second main conductor Gm2and the second sub conductor Gs2may be implemented as in the tenth embodiment. As in the eleventh embodiment, the first main conductor Gm1and the second main conductor Gm2may be connected via a conducting wire. In this case, in the relay apparatus10, the common mode choke coil22is not used. As in the twelfth embodiment, the first main conductor Gm1and the second main conductor Gm2may be connected via the connecting component61.

Fourteenth Embodiment

In the thirteenth embodiment, the relay apparatus10may not include the first main conductor Gm1. Hereinafter, the differences between the fourteenth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the thirteenth embodiment. Thus, configurations shared with the thirteenth embodiment are given the same reference sign as in the thirteenth embodiment and description thereof will be omitted.

FIG.30is a block diagram illustrating the configuration of a main portion of the relay apparatus10according to the fourteenth embodiment. The relay apparatus10according to the fourteenth embodiment has the same components of the relay apparatus10according to the thirteenth embodiment except the common mode choke coil22and the first main conductor Gm1is not provided.

The power supply circuit23is directly connected to the power supply connector20. The power supply connector20is further connected to the second main conductor Gm2. Since the first main conductor Gm1is not provided in the relay apparatus10, the power supply connector20and the communication circuit24are not connected to the first main conductor Gm1.

In the fourteenth embodiment, the communication circuit24does not execute processing of the electrical signal using the potential of the first main conductor Gm1as the reference potential. Thus, when the communication circuit24receives the differential signal via the communication bus Lb, the received differential signal is converted into a voltage signal with the reference potential corresponding to the potential of the second main conductor Gm2. The communication circuit24obtains the data included in the converted voltage signal.

FIG.31is an explanatory diagram of the arrangement of the second main conductor Gm2. Since the first main conductor Gm1is not provided in the relay apparatus10, as illustrated inFIG.31, as the second main conductor Gm2, a plate-like conductor with a large area for the main surface can be used. In this case, since the resistance value of the second main conductor Gm2is low, the potential of the second main conductor Gm2is stable.

The relay11according to the fourteenth embodiment achieves similar effects to those achieved by the relay11according to the thirteenth embodiment except for the connection effects obtained by connecting the first main conductor Gm1to the first sub conductor Gs1. The communication device according to the fourteenth embodiment achieves similar effects to those achieved by the communication device according to the thirteenth embodiment except for the connection effects and the effects achieved by the common mode choke coil22.

Fifteenth Embodiment

In the first embodiment, the first main conductor Gm1and the second main conductor Gm2may be electrically connected. Hereinafter, the differences between the fifteenth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.32is a block diagram illustrating the configuration of a main portion of the relay11according to the fifteenth embodiment.FIG.33is a circuit diagram of the signal processing circuit31. The substrate connector47included in the relay11according to the fifteenth embodiment is configured as in the thirteenth embodiment (seeFIGS.25and26). Thus, the conducting wires Wa and Wb included in the communication line Lc pass through the substrate connector47. One end portion of the connection conductor47gincluded in the substrate connector47is connected to the first sub conductor Gs1and conductively connected to the first sub conductor Gs1.

The relay11further includes an electrically connecting element80for implementing an electrical connection. The electrically connecting element80is an inductor, a resistor, a capacitor, a conducting wire, or the like. The conducting wire includes a resistance component. It is sufficient that the electrically connecting element80is a circuit element along which AC voltage propagates. One end of the electrically connecting element80is connected to the other end of the connection conductor47g. The other end of the electrically connecting element80is connected to the second sub conductor Gs2. In this manner, the electrically connecting element80is connected between the connection conductor47gand the second sub conductor Gs2.

FIG.34is an explanatory diagram of the arrangement of the electrically connecting element80. As illustrated inFIG.34, one end portion of the connection conductor47gis located inside the first sub substrate Bs1. The other end portion of the connection conductor47gis located inside the second sub substrate Bs2. The electrically connecting element80is disposed on the main surface of the first sub substrate Bs1. One end of the electrically connecting element80is located on the upper side of the first sub conductor Gs1. One end of the electrically connecting element80is connected to the first sub conductor Gs1using a through hole, for example. The other end of the electrically connecting element80is located on the upper side of the connection conductor47g. The other end of the electrically connecting element80is connected to the connection conductor47gusing a through hole, for example.

When the connection conductor47gis insulated from the second sub conductor Gs2and has a long length in the front-and-back direction, there is a possibility that the connection conductor47gfunctions as an antenna that converts electromagnetic waves propagating through the air into a current. The converted current may cause the potential of the first sub conductor Gs1to fluctuate. As a result, the converted current acts as noise. In the relay11according to the fifteenth embodiment, the electrically connecting element80is connected between the connection conductor47gand the second sub conductor Gs2. This prevents the connection conductor47gfrom functioning as an antenna.

The relay11and the communication device according to the fifteenth embodiment achieve an effect similar to that of the first embodiment. Note that the connection conductor47gof the substrate connector47may be connected to the second sub conductor Gs2and may be conductively connected to the second sub conductor Gs2. In this case, the electrically connecting element80is connected between the first sub conductor Gs1and the connection conductor47g.

When the connection conductor47gis insulated from the first sub conductor Gs1and has a long length in the front-and-back direction, there is a possibility that the connection conductor47gfunctions as an antenna that converts electromagnetic waves propagating through the air into a current. The converted current may cause the potential of the second sub conductor Gs2to fluctuate. As a result, the converted current acts as noise. Since the electrically connecting element80is connected between the first sub conductor Gs1and the connection conductor47g, the connection conductor47gis prevented from functioning as an antenna.

Also, in the fifteenth embodiment, the apparatus connector34of the relay11may be configured as in one of the second or sixth embodiment. The shape of the apparatus connector34may be similar to the shape in one of the third or fourth embodiment. The first sub substrate Bs1and the second sub substrate Bs2may be disposed as in the fifth embodiment. When the first sub conductor Gs1is conductively connected to the first main conductor Gm1, the conductive connection between the first main conductor Gm1and the first sub conductor Gs1may be implemented as in the seventh embodiment.

The shape of the communication line connector30may be similar to the shape in the eighth embodiment. As in the ninth embodiment, the box35of the relay11may be fixed to the main surface of the main substrate Bm of the relay apparatus10. The conductive connection between the second main conductor Gm2and the second sub conductor Gs2may be implemented as in the tenth embodiment. As in the eleventh embodiment, the first main conductor Gm1and the second main conductor Gm2may be connected via a conducting wire. In this case, in the relay apparatus10, the common mode choke coil22is not used. As in the twelfth embodiment, the first main conductor Gm1and the second main conductor Gm2may be connected via the connecting component61.

Sixteenth Embodiment

In the first embodiment, the apparatus connected to the relay11is not limited to the relay apparatus10. Hereinafter, the differences between the sixteenth embodiment and the first embodiment will be described. Configurations that are not described below are the same as in the first embodiment. Thus, configurations shared with the first embodiment are given the same reference sign as in the first embodiment and description thereof will be omitted.

FIG.35is a block diagram illustrating the configuration of a main portion of the communication system1according to the eleventh embodiment. When the first and the sixteenth embodiment are compared, the apparatus connected to the relay11is different. The communication system1according to the sixteenth embodiment includes a power supply apparatus15instead of the relay apparatus10. The DC power supply12supplies power to the power supply apparatus15. The power supply apparatus15supplies power to the relay11. In the eleventh embodiment, the plurality of ECUs14are connected to the relay11. As in the first embodiment, the relay11relays communication between two ECUs14.

Power Supply Apparatus15Configuration

The configuration of the power supply apparatus15is the configuration of the relay apparatus10according to the first embodiment except that the one or more bus connectors21and the communication circuit24is not provided. In the example illustrated inFIG.35, the second inductor22bconnects the first main conductor Gm1and the second main conductor Gm2. As described in the description of the first embodiment, a resistor may connect the first main conductor Gm1and the second main conductor Gm2.

The relay11and the communication device according to the eleventh embodiment achieve an effect similar to that of the first embodiment. Note that the relay11may be configured as in any one of the second to fifteenth embodiment.

When the relay11is configured as in the eleventh to fourteenth embodiment, the configuration of the power supply apparatus15is the configuration of the relay apparatus10according to the eleventh to fourteenth embodiment except that the one or more bus connectors21and the communication circuit24is not provided.

Modified Examples

In the first to sixteenth embodiments, instead of the ECUs14, another apparatus with a communication function such as a camera may be used. The ECU14and an apparatus other than the ECU14may be connected to the relay11. The communication system1according to the first to tenth embodiment may further include the relay11, the plurality of apparatuses (ECUs14), and the power supply apparatus15according to the eleventh embodiment. In this case, for example, two relays11are connected via the communication line Lc. The shared DC power supply12supplies power to the relay apparatus10and the power supply apparatus15. In the first to eleventh embodiment, the first main conductor Gm1may be connected to the first sub conductor Gs1via the apparatus connector34. In a configuration in which the apparatus connector34includes the plurality of conductive rods34p, the first main conductor Gm1is connected to the first sub conductor Gs1via one of the conductive rods34p.

In the relay11according to the first to fourth and the seventh to sixteenth embodiment, a circuit element may be disposed on both main surfaces of the first sub substrate Bs1. In the relay11according to the first to sixteenth embodiment, a circuit element may be disposed on both main surfaces of the second sub substrate Bs2. In the first to sixteenth embodiment, the number of the first projection portions36aor the number of the first projection portions38is not limited to two and may be one or three or more. Also, in the first to sixteenth embodiment, the number of the second projection portions36bor the number of the second projection portions configured in a similar manner to the first projection portions38is not limited to two and may be one or three or more.

In the relay11according to the first to sixteenth embodiment, the position where the first sub conductor Gs1is disposed is not limited to inside the first sub substrate Bs1and may be the main surface or the end surface of the first sub substrate Bs1. In a similar manner, the position where the second sub conductor Gs2is disposed is not limited to inside the second sub substrate Bs2and may be the main surface or the end surface of the second sub substrate Bs2. The position where the first main conductor Gm1is disposed is not limited to inside the first main substrate Bm1and may be the main surface or the end surface of the first main substrate Bm1. In a similar manner, the position where the second main conductor Gm2is disposed is not limited to inside the second main surface Bm2and may be the main surface of the end surface of the second main surface Bm2.

In the first to sixteenth embodiment, the communication lines Lc connected to the relay11may be communication buses. In this case, the plurality of ECUs14are connected to the communication lines Lc. Communication via the communication lines Lc is performed in a similar manner to communication via the communication buses Lb, for example. Communication via the communication lines Lc is communication according to the CAN communication protocol, for example.

The technical advantages (configuration requirements) described in the first to sixteenth embodiment can be combined with one another, and novel technical advantages can be formed by such combinations. The first to sixteenth embodiment disclosed herein are examples in all respects and should not be interpreted as limiting in any manner. The scope of the present disclosure is defined not by the foregoing description, but by the scope of the claims, and all modifications that are equivalent to or within the scope of the claims are included.