Patent Description:
<CIT> discloses an interlocking adapter configured to be attached to an electric outlet provided in a dust collector.

The interlocking adapter is configured to supply electric current to a resistor in the interlocking adapter from the electric outlet, in response to reception of an interlocking operation command transmitted from an electric power tool by a receiver of the interlocking adapter.

The interlocking adapter allows interlocking operation of the dust collector with the electric power tool without supply of an alternating current (AC) voltage from the dust collector to the electric power tool, and also eliminates wiring between the dust collector and the electric power tool.

The interlocking adapter further allows interlocking operation of an electric apparatus, such as a dust collector, with not only an AC-driven working machine, such as an electric power tool operated by an AC voltage, but also a battery-driven working machine.

In this interlocking adapter, in order to cause the electric apparatus to operate in an interlocking manner with the working machine, it is necessary to supply a load current, with which the electric apparatus can detect operation of the working machine, from the electric outlet of the electric apparatus to an electric load such as a resistor, during a working period of the working machine, as mentioned above.

Therefore, the interlocking adapter has to use an electric load which can be continuously supplied with a load current equivalent to the electric current that flows during the operation of the working machine, resulting in upsizing of the interlocking adapter.

The electric load requires heat dissipation measures by means of a heat sink and the like, since heat is generated due to flow of the electric current through the electric load. Such heat dissipation measures lead to upsizing of the interlocking adapter. The load current supplied to the electric load is wasted.

In one aspect of the present invention, it is desirable to be able to reduce power consumption of an interlocking adapter, and downsize the interlocking adapter.

An interlocking adapter in one aspect of the present invention includes a current path, an electric load, a switch, and a controller. The current path supplies a load current based on an alternating-current voltage received from an electric outlet provided in an electric apparatus. The electric load is provided in the current path. The switch is provided in the current path, and turned on and off. The current path is completed in response to the switch being turned on. The current path is interrupted in response to the switch being turned off. The controller, in response to reception of an interlocking command signal from a working machine, turns on and off the switch in synchronization with a change of the alternating-current voltage so as to supply the load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every <NUM>/<NUM> cycle of the alternating-current voltage.

In the interlocking adapter as such, upon causing the electric apparatus to operate in an interlocking manner with the working machine in response to reception of the interlocking command signal, the switch is not merely turned on to supply the load current to the electric load, but is turned on and off at a specified ratio of a time every <NUM>/<NUM> cycle of the alternating-current voltage.

Therefore, as compared to the aforementioned interlocking adapter disclosed in <CIT>, the interlocking adapter in the one aspect of the present invention can reduce an amount of the load current (in other words, effective current) supplied to the electric load in order to cause the electric apparatus operate in an interlocking manner with the working machine, and reduce power consumption. Also, since the effective current supplied to the electric load can be reduced, the interlocking adapter in the one aspect of the present disclosure can reduce an amount of heat generation of the electric load, and can be downsized.

The working machine and/or the electric apparatus may be a job-site device for performing a physical task.

An on-period during which the switch is turned on in order to cause the electric apparatus in an interlocking manner with the working machine may be associated with a detection characteristic of the load current used to determine whether the electric apparatus operates in an interlocking manner with the working machine.

In case that the electric apparatus is configured to determine whether to start interlocking operation with the working machine based on the load current supplied after a zero-cross point of the alternating-current voltage, the controller may turn on the switch only for a certain period after the zero-cross point every <NUM>/<NUM> cycle of the alternating-current voltage.

In case that the electric apparatus is configured to determine whether to start interlocking operation with the working machine based on the load current supplied before the zero-cross point of the alternating-current voltage, the controller may turn on the switch only for a certain period before the zero-cross point every <NUM>/<NUM> cycle of the alternating-current voltage.

The controller may turn on and off the switch so that the switch is turned on once for a specified period within the <NUM>/<NUM> cycle of the alternating-current voltage.

The controller may turn on and off the switch so that the switch is turned on at least twice for a specified period within the <NUM>/<NUM> cycle of the alternating-current voltage.

In this case, usability of the interlocking adapter can be improved. In other words, a user of the interlocking adapter can use the interlocking adapter to cause a different type of electric apparatus to operate in an interlocking manner with the working machine.

The electric apparatus can be configured to continue operating of the electric apparatus for a certain period even if supply of the load current is no longer detected once the electric apparatus detects that the load current is supplied from the electric outlet and starts interlocking operation with the working machine.

For example, a dust collector, which is one example of the electric apparatus, can be configured to continue operating the dust collector for a certain period and suck dust around the dust collector, even after operation of the working machine stops.

In case that the electric apparatus is configured as above, the controller may supply the load current to the electric load in accordance with an operation characteristic of the electric apparatus.

In other words, in this case, the controller, in response to reception of the interlocking command signal, may alternately execute a conduction implementation control and a conduction stop control so as to temporarily stop supply of the load current within a certain period during which the electric apparatus and the working machine continue interlocking operation with each other after the electric apparatus can no longer detect the supply of the load current.

The interlocking adapter as such can further reduce the amount of the load current (effective current) supplied to the electric load, can reduce the amount of heat generation accompanying the supply of the load current, and can be further downsized.

The controller executing the conduction implementation control may turn on and off the switch for <NUM> cycle of the alternating-current voltage or a specified control period which is longer than the <NUM> cycle so as to supply the load current from the electric outlet to the electric load. The controller executing the conduction stop control may turn off the switch for <NUM> cycle of the alternating-current voltage or a specified stop period which is longer than the <NUM> cycle so as to stop the supply of the load current.

The controller, may select one of control patterns in accordance with a selection command received by the controller. The control patterns may be different from each other in a ratio between an on-period of the switch and an off-period of the switch.

In other words, the different type of electric apparatus can have a different detection characteristic of the load current used for determining whether to operate in an interlocking manner with the working machine. The aforementioned controller can select one of the control patterns in accordance with the type of the electric apparatus.

Use of the interlocking adapter as such allows the user to cause at least two different types of electric apparatuses to operate in an interlocking manner with the working machine. Also, in this case, since the controller can change the ratio of the time to turn on and off the switch in accordance with the type of the electric apparatus, it is possible to minimize the amount of the load current supplied to the electric load in order to cause the electric apparatus to operate in an interlocking manner with the working machine and downsize the interlocking adapter.

The controller intermittently supplies the load current to the electric load by turning on and off the switch. The electric apparatus, based on the load current, determines whether to operate in an interlocking manner with the working machine.

The controller may accurately control the on-period and an off-period of the switch. In this case, the switch may include a semiconductor device such as, for example, a field effect transistor (FET) and an insulated gate bipolar transistor (IGBT) that can be turned on and off at a desired timing.

The interlocking adapter may further include a full-wave rectifier configured to rectify full wave of the alternating-current voltage and generate a rectified voltage.

In this case, the switch is turned on and off at a desired timing, so that the load current can be supplied from the electric outlet to the electric load. As a result, the electric apparatus can determine whether to operate in an interlocking manner with the working machine based on the load current.

The full-wave rectifier may include an input stage, and receive the alternating-current voltage at the input stage. The current path may be coupled to the input stage. The full-wave rectifier may include an output stage, and be configured to output the rectified voltage from the output stage. The current path may be coupled to the output stage.

A load characteristic (such as a resistance value) of the electric load may be set such that a value of the load current supplied during the on-period during which the controller turns on the switch is equal to or greater than a current value for determining implementation of interlocking operation with the working machine by the electric apparatus.

The load current supplied to the electric load during the on-period of the switch can be determined from a value of the alternating-current voltage supplied from the electric outlet when the switch is on and the load characteristic of the electric load. In other words, when the value of the alternating-current voltage is low, the load current can be reduced.

The interlocking adapter may include a voltage detector configured to detect the value of the alternating-current voltage. The controller may adjust the ratio of the time, based on the value of the alternating-current voltage detected by the voltage detector. The controller may adjust the ratio of the time so that the lower the value detected by the voltage detector is, the longer the switch is on.

In this case, without being influenced by fluctuation of the alternating-current voltage supplied from the electric outlet, it is possible to control a magnitude of the load current supplied to the electric load during the on-period of the switch to a desired magnitude of the load current which allows determination on whether to implement interlocking operation with the working machine by the electric apparatus. Thus, it is possible to cause the electric apparatus to operate in an interlocking manner, in conjunction with operation of the working machine more reliably.

The electric load may include a resistive load. The interlocking adapter may include a fan configured to cool the resistive load.

The controller may drive the fan in synchronization with the interlocking command signal.

The controller may stop the supply of the load current to the electric load in response to stop of reception of the interlocking command signal.

The controller may stop driving of the fan in response to elapse of a specified cooling time after stopping the supply of the load current. In this case, even after the supply of the load current to the electric load is stopped, it is possible to continue cooling of the electric load and inhibit an increase in temperature of the interlocking adapter.

The interlocking adapter may include a temperature detector configured to detect a temperature of the electric load.

The controller may continue driving of the fan in response to the temperature, which is detected by the temperature detector, being equal to or higher than a specified temperature after the supply of the load current is stopped. In this case, it is possible to inhibit an increase in temperature of the interlocking adapter due to heat generation of the electric load after the supply of the load current to the electric load is stopped.

The controller may determine whether the fan is normally (or properly) rotating during the supply of the load current to the electric load. The controller may stop the supply of the load current to the electric load in response to determination by the controller that the fan is not normally rotating.

In this case, it is possible to inhibit excessive heat generation of the electric load due to failure of the fan to cool the electric load during the supply of the load current to the electric load.

When the supply of the load current to the electric load is forcibly stopped due to failure of the fan, it is not possible to cause the electric apparatus to operate in an interlocking manner with the working machine.

The interlocking adapter may be configured to perform error display when the supply of the load current to the electric load is forcibly stopped. In this case, it is possible to notify the user that a reason why the electric apparatus cannot operate in an interlocking manner with the working machine is due to failure of the interlocking adapter.

The interlocking adapter may include a housing including a first outer wall surface. The interlocking adapter may include a power cord coupled to the electric outlet. The fan may be housed in the housing together with the electric apparatus. The first outer wall surface may include a first opening provided to suck an air into the housing or discharge the air from the housing. The first outer wall surface may include an insertion hole provided to insert the power cord into the housing. The power cord may be drawn out from the insertion hole to outside of the housing.

In this case, it is possible to inhibit or restrict the power cord from closing the first opening. Therefore, it is possible to secure a suction path of the air from the first opening or a discharge path of the air to the first opening, and cool the electric load by rotation of the fan.

In case that the fan is arranged near the first opening, a forced air flow can be generated through the first opening which is not to be closed. Therefore, the electric load can be more effectively cooled.

The housing may include a second outer wall surface. The second outer wall surface may include a second opening provided to suck an air into the housing or discharge the air from the housing.

The housing may include a third outer wall surface. The third outer wall surface may include a third opening provided to suck an air into the housing or discharge the air from the housing.

In this case, a passage of the air can be formed by the second opening and the third opening, in addition to the first opening. Further, even if any one of the first opening, the second opening and the third opening is closed, the passage of the air can be secured. Thus, cooling effect of the electric load by rotation of the fan can be sufficiently exerted.

The first opening, the second opening and the third opening may be arranged so as to face the electric load. The fan may be arranged between one of the first opening, the second opening and the third opening, and the electric load.

In this case, it is possible to concentrate an air flow generated by rotation of the fan on the electric load and inhibit heat from the electric load from flowing into other portion in the housing, thereby inhibiting an increase in temperature of the interlocking adapter.

The interlocking adapter may be configured to notify the user of the control pattern selected by the controller.

This notification may be performed, for example, by lighting of a LED, image display or the like. The housing may include an operating device that receives the selection command from the user. An indicator that makes the aforementioned notification may be arranged so as to avoid being covered by a hand of the user operating the operating device. Even when the error display is performed due to failure of the fan or the like, the indicator may avoid being covered by the hand of the user.

When the indicator for displaying an operation state such as the selected control pattern, an error, etc. is provided in the interlocking adapter, the indicator and the operating device may be provided on the same outer wall surface of the housing. The indicator may be arranged at an outer side of the housing than the operating device (in other words, a corner portion).

In the arrangement as above, when the user is operating the operating device while holding the housing with the hand, it is possible for the indicator arranged at the outer side of the housing to avoid being covered by the hand of the user. Therefore, the user can check the indicator while operating the operating device.

Another aspect of the present invention is a method for operating an electric apparatus in an interlocking manner with a working machine. The method includes: receiving an alternating-current voltage supplied from an electric outlet provided in an electric apparatus by an interlocking adapter; wirelessly receiving an interlocking command wirelessly transmitted from a working machine by the interlocking adapter; and turning on and off a switch in the interlocking adapter in synchronization with a change of the alternating-current voltage in response to wireless reception of the interlocking command by the interlocking adapter so as to supply a load current from the electric outlet to an electric load in the interlocking adapter, the switch and the electric load being provided in a path of the load current in the interlocking adapter, the switch being turned on and off at a specified ratio of a time every <NUM>/<NUM> cycle of the alternating-current voltage.

The method as above can exert the same effect as the aforementioned interlocking adapter.

An interlocking adapter in further another aspect of the present invention comprises: a current path provided to supply a load current based on an alternating-current voltage received from an electric outlet provided in an electric apparatus; a capacitive load provided in the current path; a switch provided in the current path and is configured to be turned on and off, the current path being completed in response to the switch being turned on, the current path being interrupted in response to the switch being turned off; and a controller configured to turn on and off the switch in synchronization with a change of the alternating-current voltage in response to reception of an interlocking command signal from a working machine to supply the load current from the electric outlet to the capacitive load, the controller being configured to turn on and off the switch at a specified ratio of a time every <NUM>/<NUM> cycle of the alternating-current voltage.

In the interlocking adapter as above, consumption of electric power is reduced in the capacitive load. Since heat generation of the capacitive load is inhibited, the interlocking adapter can be downsized.

The capacitive load may include a capacitor. The capacitor may have an equivalent series resistance (ESR), desirably a low ESR.

Example embodiments of the present invention will be described hereinafter with reference to the accompanying drawings, in which:.

As shown in <FIG>, an interlocking system of the present embodiment includes a circular saw <NUM> as one example of a working machine of the present invention.

The interlocking system further includes a dust collector <NUM>, which operates in conjunction with the circular saw <NUM>, as one example of an electric apparatus of the present invention.

The dust collector <NUM> includes a tank <NUM>. The dust collector <NUM> includes a dust collector main body <NUM> on top of the tank <NUM>. The dust collector main body <NUM> includes an alternating current (AC) motor (not shown) and a suction fan (not shown) in the dust collector main body <NUM>. The dust collector <NUM> includes a power cord <NUM> for receiving electric power from an AC power source (not shown) such as a commercial power source. The power cord <NUM> is drawn out from the tank <NUM>.

The AC motor is driven by the electric power supplied from the AC power source coupled via the power cord <NUM> and rotates the suction fan. When the suction fan is rotated by the AC motor, a hose <NUM> coupled to a suction port <NUM> of the tank <NUM> sucks dust and the like around a leading end portion of the hose <NUM> together with the air. The sucked dust and air pass through the tank <NUM> into the dust collector main body <NUM>. The air that has entered the dust collector main body <NUM> is discharged from the dust collector main body <NUM>.

A filter (not shown) is provided between the tank <NUM> and the dust collector main body <NUM>. The filter captures the dust and the like sucked via the hose <NUM>. The captured dust and the like are collected in the tank <NUM>.

The circular saw <NUM> includes a circular saw main body <NUM> including a motor (not shown). The circular saw <NUM> further includes a disc-shaped saw blade <NUM> attached to a rotation shaft protruding from the circular saw main body <NUM>. The circular saw <NUM> further includes a blade case <NUM> attached to the circular saw main body <NUM> to cover the saw blade <NUM>. The blade case <NUM> is coupled to the leading end portion of the hose <NUM> drawn out from the suction port <NUM> of the dust collector <NUM>.

The dust collector <NUM>, that operates in an interlocking manner with the circular saw <NUM> cutting a workpiece, can suck dust produced from the workpiece.

The dust collector main body <NUM> includes an electric outlet <NUM>. The electric outlet <NUM> is provided to supply AC power to a working machine such as the circular saw <NUM>. The dust collector main body <NUM> further includes a controller <NUM>. The controller <NUM> detects electric current flowing from the electric outlet <NUM> to the working machine and drives the AC motor.

The dust collector <NUM> as such can operate in an interlocking manner, for example, with an AC-driven working machine having an AC plug plugged into the electric outlet <NUM>.

The circular saw <NUM> of the present embodiment includes an attachment portion <NUM>. The attachment portion <NUM> is configured to attach a battery pack <NUM> to the circular saw main body <NUM>. The circular saw <NUM> is configured to drive a motor of the circular saw <NUM> by direct-current (DC) power supplied from the battery pack <NUM> attached to the attachment portion <NUM>.

The circular saw <NUM> includes a transmitter <NUM>. The transmitter <NUM> transmits an interlocking command signal in a wireless manner when the motor of the circular saw <NUM> is driven by operation of a user (in other words, when the workpiece is being cut). The interlocking command signal instructs an electric apparatus such as the dust collector <NUM> to operate in an interlocking manner with the circular saw <NUM>. The transmitter <NUM> in another embodiment may also transmit an additional signal, in addition to the interlocking command signal, in a wireless manner.

The electric outlet <NUM> of the dust collector <NUM> is coupled to an interlocking adapter <NUM>. The interlocking adapter <NUM> is configured to flow a specified load current into the interlocking adapter <NUM>, in response to reception of the interlocking command signal transmitted from the transmitter <NUM>.

The interlocking adapter <NUM> includes an AC plug <NUM>. The AC plug <NUM> is plugged into the electric outlet <NUM> to be electrically coupled to the dust collector <NUM>. The interlocking adapter <NUM> includes an adapter main body <NUM>. The adapter main body <NUM> receives the interlocking command signal transmitted from the transmitter <NUM>. The adapter main body <NUM> draw the load current from the dust collector <NUM> via the AC plug <NUM>, in response to reception of the interlocking command signal. The AC plug <NUM> is provided at a leading end of a power cord <NUM> drawn out from the adapter main body <NUM>.

As shown in <FIG>, the adapter main body <NUM> includes a full-wave rectifier <NUM>. The full-wave rectifier <NUM> rectifies full wave of an AC voltage supplied from the electric outlet <NUM> via the AC plug <NUM> and the power cord <NUM> so as to generate a rectified voltage. The full-wave rectifier <NUM> in the present embodiment may be provided with a bridge circuit (so-called diode bridge) configured to rectify the AC voltage with four diodes.

The rectified voltage generated by the full-wave rectifier <NUM> is applied to a series circuit formed with a resistive load <NUM>, a switching part <NUM>, and a current detector <NUM>.

The resistive load <NUM> functions as an electric load through which a load current flows. The load current is used for the dust collector <NUM> to detect operation of the working machine. More specifically, the resistive load <NUM> of the present embodiment includes a resistor through which the load current flows.

The switching part <NUM> couples/interrupts the resistive load <NUM> and the current detector <NUM>. The switching part <NUM> in the present embodiment includes an insulated gate bipolar transistor (IGBT). The switching part <NUM> in another embodiment may include another type of switching element such as a field effect transistor (FET), instead of or in addition to the IGBT.

The current detector <NUM> detects a value of the load current that flows through the current detector <NUM>. The current detector <NUM> further outputs a detection signal indicating the value of the detected load current. The current detector <NUM> may include a resistor coupled in series to the resistive load <NUM> via the switching part <NUM>, and output a voltage across the resistor as the detection signal.

The detection signal outputted from the current detector <NUM> is inputted to a controller <NUM> and an overcurrent protector <NUM>.

The overcurrent protector <NUM> forcibly turns off the switching part <NUM> when the value of the load current detected by the current detector <NUM> exceeds a threshold value preset for determination of overcurrent, so as to inhibit or restrain flowing of overcurrent to the resistive load <NUM>.

The resistive load <NUM> is provided with a temperature detector <NUM> including a thermistor. A detection signal (signal indicating temperature of the resistive load <NUM>) outputted from the temperature detector <NUM> is inputted to the controller <NUM>.

An output stage of the full-wave rectifier <NUM> (output stage of the rectified voltage) is coupled to a zero-cross detector <NUM>, in addition to the aforementioned series circuit. The zero-cross detector <NUM> detects a zero-cross point of the AC voltage supplied from the electric outlet <NUM> of the dust collector <NUM> to the AC plug <NUM>, and outputs a detection signal indicating detection of the zero-cross point. The detection signal outputted from the zero-cross detector <NUM> is inputted to the controller <NUM>.

More specifically, the zero-cross detector <NUM> detects a timing at which the rectified voltage applied from the full-wave rectifier <NUM> to the zero-cross detector <NUM> becomes zero, as the zero-cross point.

The output stage of the full-wave rectifier <NUM> is coupled to a control power supply <NUM> via a diode <NUM>. The diode <NUM> is provided to inhibit or restrain reverse flow of electric current from the control power supply <NUM> to the output stage of the full-wave rectifier <NUM>. The control power supply <NUM> generates a power supply voltage (DC constant voltage) for operating an internal circuit of the adapter main body <NUM>, such as the controller <NUM>, based on the rectified voltage supplied from the full-wave rectifier <NUM>.

A power supply voltage detector <NUM> is coupled to an input path of the rectified voltage to the control power supply <NUM>. The power supply voltage detector <NUM> detects a voltage value of the rectified voltage (in other words, voltage value of the AC voltage), and outputs a detection voltage indicating the detected voltage value to the controller <NUM>. The power supply voltage detector <NUM> may include at least two resistors, and output a rectified voltage divided by these two resistors to the controller <NUM> as the detection voltage.

The controller <NUM> includes a micro control unit (MCU) including at least a CPU, a ROM, and a RAM. Instead of or in addition to the MCU, the controller <NUM> may include, for example, a combination of electronic components such as a discrete device, an Application Specified Integrated Circuit (ASIC), an Application Specific Standard Product (ASSP), a programmable logic device such as, for example, Field Programmable Gate Array (FPGA), or a combination of the foregoing. The controller <NUM> executes a control process for supplying the load current to the resistive load <NUM> when the interlocking command signal is transmitted from the transmitter <NUM> of the circular saw <NUM>.

The controller <NUM> utilizes the zero-cross point of the AC voltage detected by the zero-cross detector <NUM> and the voltage value of the AC voltage detected by the power supply voltage detector <NUM>, in order to execute the control process.

The controller <NUM> further executes a protection process. In the protection process, the controller <NUM> determines an overheated state of the resistive load <NUM>, based on the temperature of the resistive load <NUM> detected by the temperature detector <NUM> and the value of the load current detected by the current detector <NUM>, and forcibly turns off the switching part <NUM>.

The adapter main body <NUM> is provided with a receiver <NUM>. The receiver <NUM> receives the interlocking command signal wirelessly transmitted from the transmitter <NUM> of the circular saw <NUM> in a wireless manner. The adapter main body <NUM> further includes an operating device <NUM>. The operating device <NUM> is utilized by a user of the interlocking adapter <NUM> to manually perform mode setting of the interlocking adapter <NUM>.

The operating device <NUM> includes a mode setting switch (not shown). The mode setting switch is operated so as to sequentially switch the mode setting of the interlocking adapter <NUM> to any one of a first mode, a second mode, and a third mode to be described later.

The controller <NUM> is coupled to a reception input device <NUM>. The reception input device <NUM> receives a reception signal from the receiver <NUM>. The controller <NUM> is coupled to an operation input device <NUM>. The operation input device <NUM> receives an operation signal from the operating device <NUM>.

The receiver <NUM> is a device separate from the adapter main body <NUM>, or is included in a separate device. The receiver <NUM> is detachably attached to the adapter main body <NUM>. Assuming that the adapter main body <NUM> is configured to supply electric power from the control power supply <NUM> to the receiver <NUM> when the receiver <NUM> is not attached to the adapter main body <NUM>, the user may touch a terminal provided in the adapter main body <NUM> in order to supply the electric power to the receiver <NUM> and get an electric shock, or the control power supply <NUM> may fail.

In order to avoid such a risk, the interlocking adapter <NUM> includes an insulation power supply <NUM>. The insulation power supply <NUM> receives the AC voltage through the input path of the AC voltage from the AC plug <NUM>. The insulation power supply <NUM> converts (steps down) the received AC voltage with an isolation transformer, and then generates a power supply voltage for driving the receiver <NUM>.

The receiver <NUM> receives the power supply voltage from the insulation power supply <NUM>. Therefore, even if the user touches the terminal for supplying electric power to the receiver <NUM>, direct application of the AC voltage from the AC plug <NUM> to the user can be avoided, and safety of the user can be ensured. The operating device <NUM> is a portion directly touched by the user for operation. Therefore, the operating device <NUM> receives the power supply voltage from the insulation power supply <NUM>.

Assuming that the receiver <NUM> is directly coupled to the reception input device <NUM> via a signal line, or the operating device <NUM> is directly coupled to the operation input device <NUM> via a signal line, it may not be possible to ensure safety of the user.

Thus, in the present embodiment, the receiver <NUM> is coupled to the reception input device <NUM> via a first photo coupler (not shown) including a first light emitting device (not shown) and a first light receiving device (not shown). The operating device <NUM> is coupled to the operation input device <NUM> via a second photo coupler (not shown) including a second light emitting device (not shown) and a second light receiving device (not shown). Thus, the receiver <NUM> is electrically isolated from the reception input device <NUM>, and the operating device <NUM> is electrically isolated from the operation input device <NUM>, resulting in that safety of the user can be ensured.

A varistor <NUM> that functions as a surge absorber is provided in the aforementioned input path of the AC voltage. The varistor <NUM> protects the internal circuit from incoming noise.

The controller <NUM> is coupled to an indicator <NUM>. The indicator <NUM> displays the mode setting (first mode, second mode or third mode) set via the operating device <NUM>. The indicator <NUM> may include a LED, and display the mode setting by lighting the LED.

As the mode setting that can be set via the operating device <NUM>, the first mode, the second mode, and the third mode shown in <FIG> are provided in accordance with the type of the dust collector <NUM> that can implement interlocking operation using the interlocking adapter <NUM> of the present embodiment (more specifically, detection characteristic of the load current for determination of interlocking operation in the dust collector <NUM>).

In the first mode, the controller <NUM> turns off the switching part <NUM> for a certain off-period W1 after detection of the zero-cross point for each detection cycle (that is, <NUM>/<NUM> cycle of the AC voltage) of the zero-cross point (time point t0 shown in <FIG>) by the zero-cross detector <NUM>. The controller <NUM> thereafter turns on the switching part <NUM> for a certain on-period W2 till the next zero-cross point.

The second mode is different from the first mode in ratio between a period during which the switching part <NUM> is turned on and a period during which the switching part <NUM> is turned off. The controller <NUM> in the second mode, as in the first mode, turns off the switching part <NUM> for a certain off-period W1 for each <NUM>/<NUM> cycle of the AC voltage, and thereafter turns on the switching part <NUM> for a certain on-period W2.

In the third mode, the controller <NUM>, after detection of the zero-cross point for each <NUM>/<NUM> cycle of the AC voltage, waits for a short off-period (W1) and then turns on the switching part <NUM>. The controller <NUM> then turns off the switching part <NUM> after a certain on-period W2 elapses.

The reason why the controller <NUM> in the third mode waits for a short time after detection of the zero-cross point and turns on the switching part <NUM> is because electric current flowing through the motor of the AC-driven electric power tool which is originally coupled to the electric outlet <NUM> is delayed by about <NUM> with respect to a voltage phase. In other words, the controller <NUM> in the third mode waits for a short time after detection of the zero-cross point and then turns on the switching part <NUM>, in order not to supply electric current for the delay time.

The memory (for example, ROM) of the controller <NUM> stores the off-period W1 and the on-period W2 as setting data for each of the first mode, the second mode, and the third mode. The off-period W1 corresponds to the period during which the switching part <NUM> is turned off after the zero-cross point of the AC voltage is detected, as described above. The on-period W2 corresponds to the period during which the switching part <NUM> is turned on after the off-period W1 elapses, as described above.

The off-period W1 and the on-period W2 shown in <FIG> respectively represent the off-period immediately after detection of the zero-cross point and the subsequent on-period, when the AC voltage has a frequency of <NUM> and the <NUM>/<NUM> cycle is <NUM>.

In the second mode, the controller <NUM> not only switches the on-state and the off-state of the switching part <NUM> every <NUM>/<NUM> cycle of the AC voltage, but also executes a conduction implementation control for supplying the load current in a certain conduction implementation period W3. In the conduction implementation control, the controller <NUM> switches the on-state and the off-state of the switching part <NUM> to supply the load current to the resistive load <NUM>.

After the conduction implementation period W3 elapses, the controller <NUM> executes a conduction stop control in a certain conduction stop period W4 thereafter. In the conduction stop control, the controller <NUM> holds the switching part <NUM> in the off-state and stops supply of the load current. After execution of the conduction stop control, the controller <NUM> alternately executes the conduction implementation control and the conduction stop control each time the conduction implementation period W3 or the conduction stop period W4 elapses.

Therefore, in the setting data of the second mode, as shown in <FIG>, in order to alternately execute the conduction implementation control and the conduction stop control, time indicating the conduction implementation period W3 and time indicating the conduction stop period W4 are set. In the setting data of the first mode and the setting data of the third mode, the conduction implementation period W3 and the conduction stop period W4 are set to <NUM>.

Each of the conduction implementation period W3 and the conduction stop period W4 is set longer than <NUM> cycle of the AC voltage. The conduction implementation period W3 may be set to any time during which the dust collector <NUM> can determine implementation of interlocking operation. For example, the conduction implementation period W3 may be set to <NUM> cycle of the AC voltage.

Also, the conduction stop period W4 may be set shorter than operation continuation time from when the dust collector <NUM> stops detection of the specified load current until driving of the AC motor is stopped.

The longer the conduction stop period W4 is, the smaller an amount of current (effective current) supplied to the resistive load <NUM> for interlocking operation is, resulting in reduction in power consumption of the interlocking adapter <NUM>. The conduction stop period W4 corresponding to <NUM> cycle of the AC voltage can reduce power consumption, as compared to continuous execution of the conduction implementation control. Therefore, the conduction stop period W4, similar to the conduction implementation period W3, may be set to <NUM> cycle of the AC voltage.

The control process executed by the controller <NUM> to operate the dust collector <NUM> in an interlocking manner with the circular saw <NUM> will be described.

As shown in <FIG> and <FIG>, when the control process is started, the controller <NUM> checks the current mode setting (that is, whether it is the first mode, the second mode, or the third mode) in S110. The controller <NUM> reads a current voltage value Vnow of the AC voltage from the power supply voltage detector <NUM> in S120.

In S130, the controller <NUM> reads the off-period W1 and the on-period W2 from the setting data corresponding to the current mode setting, corrects each of the off-period W1 and the on-period W2 using the voltage value Vnow, and sets the corrected off-period W1 and the corrected on-period W2 as a timer value for measurement by a timer.

As shown in <FIG>, when the AC voltage supplied from the electric outlet <NUM> of the dust collector <NUM> decreases, the amount of the load current supplied to the resistive load <NUM> during the on-period W2 of the switching part <NUM> decreases. There is a possibility that the dust collector <NUM> can no longer determine implementation of interlocking operation.

Therefore, each of the off-period W1 and the on-period W2 is corrected so that the amount of electric current flowing through the resistive load <NUM> during the on-period W2 of the switching part <NUM> is an amount required for the dust collector <NUM> to determine implementation of interlocking operation, and set as the timer value.

In S130, the controller <NUM> corrects the off-period W1 and the on-period W2 based on a ratio between a reference voltage value Vref corresponding to the setting data and the voltage value Vnow. More specifically, the controller <NUM> corrects the off-period W1 and the on-period W2 so that the on-period W2 is longer when the voltage value Vnow is lower than the reference voltage value Vref. When the voltage value Vnow is higher than the reference voltage value Vref, the controller <NUM> corrects the off-period W1 and the on-period W2 so that the on-period W2 is shorter.

Next in S140, the controller <NUM> reads the conduction implementation period W3 and the conduction stop period W4 from the setting data corresponding to the mode setting, and sets each of the periods W3, W4 as the timer value.

In this way, when the timer value of each of the periods W1 to S4 is set, the controller <NUM> proceeds to S150, and determines whether the interlocking command signal transmitted from the transmitter <NUM> of the circular saw <NUM> is received by the receiver <NUM>. If the interlocking command signal is not received (S150: NO), then the controller <NUM> proceeds to S110. If the interlocking command signal is received (S150: YES), then the controller <NUM> proceeds to S160.

In S160, the controller <NUM> determines whether the zero-cross point of the AC voltage is detected by the zero-cross detector <NUM>, and waits for the detection of the zero-cross point (S160: NO). When the zero-cross point is detected (S160: YES), the controller <NUM> proceeds to S170, and determines whether the off-period W1 set as the timer value has elapsed, and waits for the elapse of the off-period W1 (S170: NO).

When it is determined in S170 that the off-period W1 has elapsed (S170: YES), the controller <NUM> proceeds to S180, switches the switching part <NUM> from the off-state to the on-state, starts supply of the load current to the resistive load <NUM>, and proceeds to S190.

In S190, the controller <NUM>, after switching the switching part <NUM> to the on-state in S180, determines whether the on-period W2 set as the timer value has elapsed. In S190, if it is determined that the on-period W2 has not elapsed (S190: NO), then the controller <NUM> proceeds to S200, and determines whether the temperature of the resistive load <NUM> detected by the temperature detector <NUM> is normal (or proper), more specifically, whether it is lower than a maximum temperature set in advance.

In S200, if it is determined that the temperature of the resistive load <NUM> is lower than the maximum temperature and is normal (S200: YES), then the controller <NUM> proceeds to S210, and determines whether a value of the load current detected by the current detector <NUM> is lower than a maximum value and is normal (or proper). In S210, if it is determined that the value of the load current is lower than the maximum value and is normal (S210: YES), then the controller <NUM> proceeds to S190 again, and determines whether the on-period W2 has elapsed.

In S200, if it is determined that the temperature of the resistive load <NUM> is abnormal (or improper) (S200: NO) or in S210 that the value of the load current is abnormal (or improper) (S210: NO), then the controller <NUM> proceeds to S220, executes an error process, and terminates the control process. In the error process, the controller <NUM> switches the switching part <NUM> to the off-state, and displays the abnormal state on the indicator <NUM>.

If it is determined in S190 that the on-period W2 has elapsed (S190: YES), then the controller <NUM> proceeds to S230, switches the switching part <NUM> to the off-state, and stops supply of the load current. In subsequent S240, the controller <NUM> determines whether the conduction implementation period W3 set as the timer value in S140 has elapsed. If it is determined in S240 that the conduction implementation period W3 has not elapsed (S240: NO), then the controller <NUM> proceeds to S110. If it is determined in S240 that the conduction implementation period W3 has elapsed (S240: YES), then the controller <NUM> proceeds to S260.

In S260, the controller <NUM> checks the current mode setting as in S110, and proceeds to S270. In S270, the controller <NUM> determines whether the mode setting is changed. If it is determined that the mode setting is changed (S270: YES), then the controller <NUM> proceeds to S120.

In S270, if it is determined that the mode setting is not changed (S270: NO), then the controller <NUM> proceeds to S280, and determines whether the interlocking command signal is received by the receiver <NUM> as in S150.

If it is determined in S280 that the interlocking command signal is not received (S280: NO), then the controller <NUM> proceeds to S110. If it is determined in S280 that the interlocking command signal is received (S280: YES), then the controller <NUM> proceeds to S290, where it is determined whether the conduction stop period W4 set as the timer value in S140 has elapsed after it is determined in S240 that the conduction implementation period W3 has elapsed.

When it is determined in S290 that the conduction stop period W4 has elapsed (S290: YES), the controller <NUM> proceeds to S110. When it is determined in S290 that the conduction stop period W4 has not elapsed (S290: NO), the controller <NUM> proceeds to S260.

As above, the controller <NUM> executes the control process by way of procedures shown in <FIG> and <FIG>, and thereby the on-state and the off-state of the switching part <NUM> is switched in synchronization with the change of the AC voltage, in accordance with the mode setting set by operation of the user of the operating device <NUM>.

The control pattern of the switching part <NUM> in each of the first mode, the second mode, and the third mode is set in advance as shown in <FIG>. The switching part <NUM> is turned on and off at a specified ratio of a time every <NUM>/<NUM> cycle of the AC voltage.

Therefore, according to the interlocking adapter <NUM> of the present embodiment, as compared to the aforementioned interlocking adapter disclosed in <CIT>, it is possible to reduce the amount of the load current (in other words, effective current value) supplied to the resistive load <NUM> in order to operate the dust collector <NUM> in an interlocking manner with the circular saw <NUM>, and reduce power consumption. Since the load current supplied to the resistive load <NUM> can be reduced, it is possible to reduce an amount of heat generation of the resistive load <NUM>, and downsize the interlocking adapter <NUM>.

In the mode setting of the interlocking adapter <NUM>, the first mode, the second mode, and the third mode are set in accordance with the detection characteristic of the load current of the dust collector <NUM> operated in an interlocking manner with the circular saw <NUM> using the interlocking adapter <NUM>.

The user can select the mode setting by operating the operating device <NUM>.

Therefore, by selecting the mode setting of the interlocking adapter <NUM> in accordance with the type of the dust collector <NUM>, the user can set a supply period of the load current, that is supplied to the resistive load <NUM> to operate the dust collector <NUM> in an interlocking manner, to a minimum, and reduce power consumption of the interlocking adapter <NUM>.

In the second mode, the control pattern of the switching part <NUM> is set so that the conduction implementation control and the conduction stop control are alternately executed in accordance with an operation characteristic of the dust collector <NUM> during the interlocking operation. Therefore, in the second mode, as compared to the first mode and the third mode, electric current supplied to the resistive load <NUM> for interlocking operation can be further reduced.

The interlocking adapter <NUM> of the present first embodiment, by operation of the operating device <NUM> to switch the mode setting, can operate several types of dust collectors <NUM> in an interlocking manner. Therefore, usability of the circular saw <NUM> and/or the dust collector <NUM> can be improved.

One embodiment of the present invention has been described in the above, but the interlocking adapter <NUM> of the present invention is not limited to the aforementioned first embodiment, and can be practiced in various modes.

In the aforementioned first embodiment, three modes in accordance with the type of the dust collector <NUM>, that is, three modes corresponding to the detection characteristic of the load current in the dust collector <NUM> are set, and the user selects one of the modes.

The control pattern of the switching part <NUM> shown in <FIG> is one example of a single control pattern from which any of a plurality of types of dust collectors specified in advance can detect the load current and determine implementation of interlocking operation.

The interlocking adapter <NUM> may switch the switching part <NUM> to the on-state or the off-state according to the single control pattern shown in <FIG> when receiving the interlocking command signal from the circular saw <NUM>. As a result, the user no longer requires change of the mode setting. Usability of the interlocking adapter <NUM> can be enhanced.

The control pattern shown in <FIG> is set so as to have a first on-period and a second on-period every <NUM>/<NUM> cycle of the AC voltage. The switching part <NUM> is turned on in each of the first on-period and the second on-period.

A length of the second on-period (second half conduction on-period) is set such that the magnitude of the load current is alternately switched to be large or small for each specified period W5, W6 which is longer than <NUM> cycle of the AC voltage.

In the period W5, for every <NUM>/<NUM> cycle of the AC voltage, the switching part <NUM> is turned on for the same on-period W2 as the on-period W2 of the third mode of the aforementioned first embodiment in a first half of the <NUM>/<NUM> cycle. In the second half of the <NUM>/<NUM> cycle, the switching part <NUM> is turned on for the same on-period W4 as the on-period W2 of the second mode of the aforementioned first embodiment.

In the W6, for every <NUM>/<NUM> cycle of the AC voltage, the switching part <NUM> is turned on for the same on-period W2 as the on-period W2 of the third mode of the aforementioned first embodiment in the first half of the <NUM>/<NUM> cycle. In the second half of the <NUM>/<NUM> cycle, the switching part <NUM> is turned on for the same on-period W8 as the on-period W2 of the first mode of the aforementioned first embodiment.

Therefore, by turning on and off the switching part <NUM> in the control pattern of the present variation, the load current supplied by switching the mode setting in the aforementioned first embodiment can be supplied in one control pattern.

Setting data of the control pattern in the period W5 include the off-period W1, the on-period W2, the off-period W3, and the on-period W4. The off-period W1 is set to a period during which the switching part <NUM> is turned off after detection of the zero-cross point. The off-period W2 is set to a period during which the switching part <NUM> is turned on after elapse of the off-period W1. The off-period W3 is set to a period during which the switching part <NUM> is turned off after elapse of the on-period W2. The on-period W4 is set to a period during which the switching part <NUM> is turned on after elapse of the off-period W3 until the next zero-cross point.

Setting data of the control patter in the period W6 includes the off-period W1, the on-period W2, the off-period W7, and the on-period W8. The off-period W1 and the on-period W2 are the same as the off-period W1 and the on-period W2 in the period W5, respectively. The off-period W7 is set to a period during which the switching part <NUM> is turned off after elapse of the on-period W2. The off-period W7 is set to be longer than the off-period W3 in the period W5. The on-period W8 is set to a period during which the switching part <NUM> is turned on after elapse of the off-period W7 until the next zero-cross point. The on-period W8 is set to be shorter than the on-period W4 in the period W5.

As a result, in the period W6, as compared to the period W5, the magnitude of the load current supplied within <NUM>/2cycle of the AC voltage is reduced.

A control process will be described which is executed by the controller <NUM> in order to turn on and off the switching part <NUM> in the control pattern shown in <FIG> and supply the load current to the resistive load <NUM>.

As shown in <FIG>, in this control process, the controller <NUM> first determines in S310 whether the interlocking command signal transmitted from the transmitter <NUM> of the circular saw <NUM> is received by the receiver <NUM>, and waits for reception of the interlocking command signal (S310: NO).

If the interlocking command signal is received (S310: YES), then the controller <NUM> proceeds to S320, and reads the voltage value Vnow of the current AC voltage from the power supply voltage detector76.

In subsequent S330, the controller <NUM>, using the voltage value Vnow read in S320, corrects the periods W1 to W4, W7, W8 defined by the control pattern.

This correction is a process for inhibiting or restricting fluctuation of the magnitude of the load current supplied to the resistive load <NUM> caused by fluctuation of the AC voltage. By this process, each of the periods W1 to W4, W7, W8 is corrected based on a ratio between the reference voltage value Vref corresponding to the setting data of the control pattern and the voltage value Vnow, as in the aforementioned S130.

In S330, the controller <NUM> sets the corrected periods W1 to W4, W7, W8 to the respective timers as the timer value.

In subsequent S340, the controller <NUM> reads the periods W5 and W6 from the setting data of the control pattern, and sets the read periods W5 and W6 to the respective timers as the timer value.

After setting the timer values of the periods W1 to W8, the controller <NUM> proceeds to S350, determines whether the zero-cross point of the AC voltage has been detected by the zero-cross detector <NUM>, and waits for detection of the zero-cross point (S350: NO).

When the zero-cross point is detected (S350: YES), the controller <NUM> proceeds to S360, determines whether the off-period W1 has elapsed based on the timer value set to the timer after detection of the zero-cross point, and waits for elapse of the off-period W1 (S360: NO).

In S360, if it is determined that the off-period W1 has elapsed (S360: YES), the controller <NUM> proceeds to S370, switches the switching part <NUM> from the off-state to the on-state, starts supply of the load current to the resistive load <NUM>, and proceeds to S380.

In S380, the controller <NUM> determines whether the on-period W2 has elapsed based on the timer value set to the timer after switching the switching part <NUM> to the on-state in S370. If it is determined in S380 that the on-period W2 has not elapsed (S380: NO), then the controller <NUM> proceeds to S390, and determines whether the temperature of the resistive load <NUM> detected by the temperature detector <NUM> is normal.

In S390, when it is determined that the temperature of the resistive load <NUM> is lower than the maximum temperature and is normal (S390: YES), the controller <NUM> proceeds to S400, and determines whether the value of the load current detected by the current detector <NUM> is normal. In S400, if it is determined that the value of the load current is lower than the maximum value and is normal (S400: YES), then the controller <NUM> again proceeds to S380, and determines whether the on-period W2 has elapsed.

If it is determined in S390 that the temperature of the resistive load <NUM> is abnormal (S390: NO) or in S400 that the value of the load current is abnormal (S400: NO), then the controller <NUM> proceeds to S470, executes the error process, and terminates the control process. In the error process, the controller <NUM> switches the switching part <NUM> to the off-state, and displays the abnormal state on the indicator <NUM>.

If it is determined in S380 that the on-period W2 has elapsed (S380: YES), then the controller <NUM> proceeds to S410, switches the switching part <NUM> to the off-state, and stops supply of the load current. In subsequent S420, the controller <NUM> determines whether the off-period W3 has elapsed based on the timer value set to the corresponding timer after turning off the switching part <NUM> in S410, and waits for elapse of the off-period W3 (S420: NO).

If it is determined in S420 that the off-period W3 has elapsed (S420: YES), then the controller <NUM> proceeds to S430, and switches the switching part <NUM> to the on-state. In subsequent S480, the controller <NUM> determines whether the on-period W4 has elapsed after switching the switching part <NUM> to the on-state based on the timer value set to the corresponding timer.

If it is determined in S480 that the on-period W4 has not elapsed, then the controller <NUM> proceeds to S450, and determines whether the temperature of the resistive load <NUM> detected by the temperature detector <NUM> is normal.

If it is determined in S450 that the temperature of the resistive load <NUM> is lower than the maximum temperature and is normal (S450: YES), then the controller <NUM> proceeds to S460, and determines whether the value of the load current detected by the current detector <NUM> is normal.

When it is determined in S460 that the value the load current is lower than the maximum value and is normal (S460: YES), the controller <NUM> again proceeds to S480, and determines whether the on-period W4 has elapsed.

If it is determined in S450 that the temperature of the resistive load <NUM> is abnormal (S450: NO) or in S460 that the value of the load current is abnormal (S460: NO), then the controller <NUM> proceeds to S470, executes the error process, and terminates the control process.

When it is determined in S480 that the on-period W4 has elapsed, the controller <NUM> proceeds to S490, and switches the switching part <NUM> to the off-state. In subsequent S500, the controller <NUM> determines whether the interlocking command signal is received by the receiver <NUM>.

If it is determined in S500 that the interlocking command signal is not received (S500: NO), then the controller <NUM> proceeds to S310. If it is determined in S500 that the interlocking command signal is received (S500: YES), then the controller <NUM> proceeds to S510, and determines whether the period W5 has elapsed based on the timer value set to the corresponding timer. When it is determined in S510 that the period W5 has not elapsed (S510: NO), the controller <NUM> proceeds to S550 to be explained later. When it is determined in S510 that the period W5 has elapsed (S510: YES), the controller <NUM> proceeds to S520, and set <NUM> seconds to the corresponding timer as the timer value of the period W5.

In subsequent S530, the controller <NUM> determines whether the period W6 set as the timer value has elapsed after it is determined that the period W5 has elapsed. When it is determined in S530 that the period W6 has not elapsed (S530: NO), the controller <NUM> in S580 reads the voltage value Vnow of the current AC voltage from the power supply voltage detector <NUM>, and in subsequent S590, using the read voltage value Vnow, corrects the periods W7, W8 defined in the control pattern.

In S590, the controller <NUM> set the corrected periods W7, W8 as the timer values of the periods W3, W4, and proceeds to S570.

The reason why the controller <NUM> in S590 sets the corrected periods W7, W8 as the timer values of the periods W3, W4 is to change the control pattern of the switching part <NUM> to a control pattern for supplying a small current, and drive the switching part <NUM> in the changed control pattern in the aforementioned process of S350 to S490.

When it is determined in S530 that the period W6 has elapsed (S530: YES), the controller <NUM> proceeds to S540, sets the timer values of the periods W5, W6, and proceeds to S550.

The controller <NUM> reads the voltage value Vnow from power supply voltage detector <NUM> in S550, and, using the read voltage value Vnow, corrects the periods W3, W4 defined in the control pattern in subsequent S560.

In S560, the controller <NUM> further sets the corrected periods W3, W4 as the timer values of the periods W3, W4, and proceeds to S570. In S570, the controller <NUM> corrects the periods W1, W2 based on the voltage value Vnow read in S580 or S550, and sets the timer values of the corrected periods W1, W2 to the corresponding timers. When the process of S570 is executed, the controller <NUM> proceeds to S350, and executes the processes after S350.

As above, when the controller <NUM> executes the control process shown in <FIG>, it is possible to control the switching part <NUM> in the control pattern shown in <FIG> and supply to the resistive load <NUM> the load current that can cause different types of dust collectors to operate in an interlocking manner with the circular saw <NUM>.

A second embodiment of the present invention will be described below.

The interlocking adapter <NUM> of the second embodiment has a configuration substantially similar to the interlocking adapter <NUM> of the first embodiment. The second embodiment is different from the first embodiment in that a fan for cooling the resistive load <NUM> is provided in the adapter main body <NUM>.

In the second embodiment, a difference from the first embodiment, such as a driving method of the fan will be described, and the same configuration as that of the first embodiment will not be repeated.

As shown in <FIG>, the adapter main body <NUM> includes a fan motor <NUM>. A cooling fan <NUM> is integrally assembled to the fan motor <NUM> of the second embodiment. The adapter main body <NUM> further includes a drive circuit <NUM>. The drive circuit <NUM> is configured to receive electric power from the control power supply <NUM> to drive the fan motor <NUM>.

More specifically, the drive circuit <NUM> includes a FET <NUM> provided in a current path to the fan motor <NUM>. The drive circuit <NUM> further includes a transistor <NUM>. The transistor <NUM> is coupled to resistors so as to be turned on by a drive signal from the controller <NUM>, set a voltage of a gate of the FET <NUM> to low level, and turn on the FET <NUM>.

The fan motor <NUM> is configured to output a pulse signal in accordance with rotation of the fan motor <NUM>. The pulse signal (rotation pulse) is inputted to the controller <NUM>.

In addition to the switching part <NUM> and the current detector <NUM>, a protection switch <NUM> is provided in a current path passing through the resistive load <NUM> from the full-wave rectifier <NUM>. In the second embodiment, the switching part <NUM> functions as a switch to complete and interrupt the current path passing through the resistive load <NUM> in order to supply and interrupt the load current (hereinafter, the switching part <NUM> is referred to as "conduction switch <NUM>"). The protection switch <NUM> is provided so as to be able to interrupt the current path passing through the resistive load <NUM> when the conduction switch <NUM> fails.

The adapter main body <NUM> includes a mode indicator 84A instead of the indicator <NUM>. The mode indicator 84A is configured to display the operation mode by three LEDs. The adapter main body <NUM> further includes an error indicator 84B. The error indicator 84B is configured to display errors by lighting one LED.

The controller <NUM> in the second embodiment executes the control process by way of procedures substantially similar to those of the first embodiment. However, since the adapter main body <NUM> in the second embodiment includes the fan motor <NUM>, the controller <NUM> in the second embodiment, as shown in <FIG>, executes a fan motor control process of S600 after setting the timer value in S140.

After executing the fan motor control process of S600, the controller <NUM> proceeds to S800 to execute a failure diagnosis process of the switching part including the conduction switch <NUM> and the protection switch <NUM>, and proceeds to S150.

When it is determined in S160 that the zero-cross point of the AC voltage is detected by the zero-cross detector <NUM> (S160: YES), the controller <NUM> proceeds to S165 shown in <FIG>, and determines whether failure of the fan motor <NUM> is detected in the fan motor control process or whether failure of the switching part is detected in the switching part failure diagnosis process.

When it is determined in S165 that the fan motor <NUM> and the switching part are normal (or in proper condition) (S165: YES), the controller <NUM> proceeds to S170. When it is determined in S165 that the fan motor <NUM> or the switching part has failed, the controller <NUM> proceeds to S220 and lights the LED of the error indicator 84B.

In S220, the controller <NUM> lights the LED of the error indicator 84B and performs error display also when it is determined in S200 or S210 that the detected temperature or the detected value of electric current are abnormal.

Since the conduction switch <NUM> and the protection switch <NUM> are provided in the current path passing through the resistive load <NUM>, the controller <NUM>, when controlling supply of the load current in S180 and S230, holds the protection switch <NUM> to be on-state and turns on and off the conduction switch <NUM>.

When it is determined in S150 that the interlocking command signal is not received by the receiver <NUM> (S150: NO), the controller <NUM> in S250 turns off the conduction switch <NUM> and the protection switch <NUM> and proceeds to S110.

The fan motor control process executed in S600 will be described.

As shown in <FIG> and <FIG>, in the fan motor control process, the controller <NUM> determines first in S610 whether the fan motor <NUM> is being driven. If the fan motor <NUM> is not being driven (S610: NO), the controller <NUM> proceeds to S620 and determines whether the interlocking command signal is received by the receiver <NUM>.

When it is determined in S620 that the interlocking command signal is received (S620: YES), the controller <NUM> in subsequent S630 drives the fan motor <NUM> and temporarily terminates the fan motor control process. When it is determined in S620 that the interlocking command signal is not received (S620: NO), the controller <NUM> immediately terminates the fan motor control process.

When it is determined in S610 that the fan motor <NUM> is being driven (S610: YES), the controller <NUM> proceeds to S640, and determines whether the fan motor <NUM> is rotating normally based on the rotation pulse inputted from the fan motor <NUM>.

When it is determined in S640 that the fan motor <NUM> is rotating normally (S640: YES), the controller <NUM> proceeds to S650, clears a stop time counter that measures stop time of the fan motor <NUM>, and proceeds to S660. In S660, the controller <NUM> determines whether a temperature of the resistive load <NUM> detected by the temperature detector <NUM> is a high temperature equal to or higher than a specified temperature.

When it is determined in S660 that the resistive load <NUM> has the high temperature (S660: YES), the controller <NUM> proceeds to S670, and clears a non-reception time counter for measuring a non-reception time during which the interlocking command signal is not received. When completing clearing of the non-reception time counter, the controller <NUM> temporarily terminates the fan motor control process. When it is determined in S660 that the temperature of the resistive load <NUM> is not high (S660: NO), the controller <NUM> proceeds to S680, and determines whether the interlocking command signal is received by the receiver <NUM>.

When it is determined in S680 that the interlocking command signal is received (S680: YES), the controller <NUM> proceeds to S670, clears the non-reception time counter, and temporarily terminates the fan motor control process. When it is determined in S680 that the interlocking command signal is not received (S680: NO), the controller <NUM> proceeds to S690, updates (increments) the non-reception time counter, and proceeds to S700.

In S700, the controller <NUM> determines whether the non-reception time is equal to a specified time (T1) or more, based on a value of the non-reception time counter updated in S690. If the non-reception time in S700 is equal to the specified time (T1) or more (S700: YES), then the controller <NUM> proceeds to S710, stops driving of the fan motor <NUM>, and temporarily stops the fan motor control process. If the non-reception time in S700 is smaller than the specified time (T1) (S700: NO), then the controller <NUM> temporarily terminates the fan motor control process immediately.

The non-reception time counter is cleared not only when the interlocking command signal is received as mentioned above but also when the resistive load <NUM> has the high temperature. Therefore, the non-reception time counter is not updated (incremented) until the resistive load <NUM> has a temperature lower than the specified temperature.

Thus, the fan motor <NUM> continues to rotate when the temperature of the resistive load <NUM> is high. When the temperature of the resistive load <NUM> is lowered and time during which the interlocking command signal is not received elapses for the specified time (T1) or more, the fan motor <NUM> is stopped.

When it is determined in S640 that the fan motor <NUM> is not rotating normally (in other words, the fan motor <NUM> is stopped, or is rotating at an extremely low speed) (S640: NO), the controller <NUM> proceeds to S720, and updates (increments) the stop time counter.

In subsequent S730, the controller <NUM> determines whether a stop state of the fan motor <NUM> (more particularly, state in which the fan motor <NUM> is stopped or is rotating at an extremely low speed) continues based on the value of the stop time counter. If the stop state does not continue (S730: NO), then the controller <NUM> proceeds to S660.

On the other hand, when it is determined that the stop state continues (S730: YES), the controller <NUM> proceeds to S740, detects failure of the fan motor <NUM>, stores the detected failure, and proceeds to S710.

In other words, the controller <NUM>, when the stop state continues for a given length of time or more, determines that the fan motor <NUM> has failed and stops driving of the fan motor <NUM>.

In the fan motor control process as such, the controller <NUM>, when the interlocking command signal is received by the receiver <NUM>, starts driving of the fan motor <NUM>. Thereafter, when the interlocking command signal is no longer received and the stop state continues for the specified time (T1) or more, the controller <NUM> stops driving of the fan motor <NUM>. When the temperature of the resistive load <NUM> is high, the controller <NUM> continues driving of the fan motor <NUM>. When the temperature of the resistive load <NUM> is lowered, and the specified time (T1) or more elapses, the controller <NUM> stops driving of the fan motor <NUM>.

Thus, according to the second embodiment, when electric current is supplied to the resistive load <NUM> for interlocking operation, it is possible to inhibit increase in temperature of the adapter main body <NUM> due to heat generation of the resistive load <NUM>. Further, it is possible to inhibit increase in temperature of the adapter main body <NUM> due to heat of the resistive load <NUM>, after driving of the fan motor <NUM> is stopped.

The switching part failure diagnosis process executed in S800 will be described.

As shown in <FIG>, in the switching part failure diagnosis process, the controller <NUM> determines in S810 whether the interlocking command signal is received by the receiver <NUM>, and a change of state has occurred from a non-reception state of the interlocking command signal to a received state of the interlocking command signal.

When it is determined in S810 that a change of state has occurred (S810: YES), the controller <NUM> proceeds to S820. When it is determined in S810 that a change of state has not occurred (S810: NO), the controller <NUM> terminates the switching part failure diagnosis process.

In S820, the controller <NUM> sets the conduction switch <NUM> to the on-state, and the protection switch <NUM> to the off-state, and proceeds to S830. In S830, the controller <NUM> determines whether detection of electric current by the current detector <NUM> is normal (or proper), and determines whether the protection switch <NUM> set to the off-state is interrupting the current path of the load current normally.

When it is determined in S830 that the detection of electric current by the current detector <NUM> is normal (S830: YES), the controller <NUM> proceeds to S840, sets the conduction switch <NUM> to the off-state and the protection switch <NUM> to the on-state, and proceeds to S850. In S850, the controller <NUM> determines whether the detection of electric current by the current detector <NUM> is normal, and whether the conduction switch <NUM> set to the off-state is interrupting the current path of the load current normally.

When it is determined in S850 that the detection of electric current by the current detector <NUM> is normal (S850: YES), the controller <NUM> determines that both the conduction switch <NUM> and the protection switch <NUM> are normal (or in proper condition), and proceeds to S860. In S860, the controller <NUM> sets the conduction switch <NUM> and the protection switch <NUM> to the off-state, and terminates the switching part failure diagnosis process.

When it is determined in S830 or S850 that detection of the electric current by the current detector <NUM> is abnormal (or improper) (S830 or S850: NO), there is a possibility that the protection switch <NUM> or the conduction switch <NUM> has failed. The controller <NUM> proceeds to S870, stores the failure of the switching part, and proceeds to S860.

In the switching part failure diagnosis process, the controller <NUM> sets one of the conduction switch <NUM> and the protection switch <NUM> to the off-state and determines whether the load current is detected by the current detector <NUM>, thereby detecting the failure of the switching part set to the off-state.

When detecting the failure of the conduction switch <NUM> or the protection switch <NUM> in the switching part failure diagnosis process, or detecting the failure of the fan motor <NUM> in the fan motor control process, the controller <NUM> determines occurrence of failure in the determination process of S165, and prohibits supply of electric current to the resistive load <NUM>. In this case, the controller <NUM> performs error display to the error indicator 84B in the error process of S220.

Thus, the user, when it is not possible to operate the dust collector <NUM> in an interlocking manner, can confirm that the cause is the failure of the interlocking adapter <NUM> from the error display of the error indicator 84B.

When performing the error display in the error process in S220, the controller <NUM> may not only merely stop supply of electric current to the resistive load <NUM>, but also may continue the error display during reception of the interlocking command signal by the receiver <NUM>. Alternatively, the controller <NUM> may continue error display until elapse of the given length of time from when the interlocking command signal is no longer received by the receiver <NUM>.

If the error display continues as mentioned above, then failure of the interlocking adapter <NUM> can be notified to the user even when the user is away from the interlocking adapter <NUM> and cannot immediately check the error display. The controller <NUM>, when performing the error display in S220, may notify the error by sound such as sounding a buzzer at the same time.

In the error process of S220, the controller <NUM>, depending on detail of the detected failure, may notify the user of the detail of the failure such as by changing a display manner of the error or sounding pattern of the buzzer. Specifically, a notification manner of error may be changed depending on the detail of the failure. For example, failure of the fan may be notified by turning on a red light or sounding of the buzzer, and failure of the switch may be notified by flashing a red light or intermittent sounding of the buzzer. As a result, the user can detect the detail of the failure.

The controller <NUM> may execute the error process of S220 also when the power supply voltage detected by the power supply voltage detector76 is out of a guaranteed operating range, or when the frequency of the power supply voltage is out of the guaranteed operating range.

The controller <NUM> may not only perform the error display in the error process of S220 but also report error to the tool (for example, circular saw <NUM>) by wireless communication. In this case, it is possible to notify the user of the error via the tool. The user can more reliably detect the failure of the interlocking adapter <NUM> by the notification.

A structure of the interlocking adapter <NUM> (specifically, adapter main body <NUM>) of the second embodiment will be described.

As shown in <FIG>, the adapter main body <NUM> includes a rectangular housing <NUM>. The housing <NUM> houses the aforementioned components including the resistive load <NUM> and the fan motor <NUM>.

The housing <NUM> includes an upper case <NUM> and a lower case <NUM>, and is assembled as a single housing having an internal space. Specifically, an opening portion of the upper case <NUM> is overlapped with an opening portion of the lower case <NUM>, and the upper case <NUM> is coupled to the lower case <NUM> by screws.

As shown in <FIG>, an outer wall surface of the upper case <NUM> facing the lower case <NUM> is provided with a protective cover 80A which covers the receiver <NUM> housed in the housing <NUM>.

The receiver <NUM>, as shown in <FIG>, is coupled to a connector 86A of the reception input device <NUM> inside the housing <NUM>. Therefore, the user can open the protective cover 80A, and couple the receiver <NUM> to the connector 86A or detach the receiver <NUM> from the connector 86A.

As shown in <FIG>, the housing <NUM> is provided with an operation panel <NUM>. The operation panel <NUM> is positioned on the lower side in <FIG>, and provided on a side wall along a longitudinal direction of the housing <NUM>. The operation panel <NUM> is provided with the three LEDs included in the mode indicator 84A. The operation panel <NUM> is provided with the one LED included in the error indicator 84B. The operation panel <NUM> is further provided with the switch included in the operating device <NUM>.

The receiver <NUM> and the operation panel <NUM> are arranged at a position biased in one direction (left direction in <FIG>) from a longitudinal center portion of the housing <NUM>. As shown in <FIG>, the housing <NUM> includes intake ports <NUM> for taking external air into the housing <NUM> on three outer wall surfaces. These three outer wall surfaces include an outer wall surface provided with the receiver <NUM>, an outer wall surface provided with the operation panel <NUM>, and an outer wall surface of the lower case <NUM> facing the upper case <NUM>.

The intake ports <NUM> are arranged at a position biased on an opposite side (right direction in <FIG>) of the receiver <NUM> and the operation panel <NUM> from the longitudinal center portion of the housing <NUM>, in the corresponding outer wall surface.

This is because the resistive load <NUM> is arranged, inside the housing <NUM>, at a position biased to the opposite side of the receiver <NUM> and the operation panel <NUM> from the longitudinal center portion of the housing <NUM>, as shown in <FIG>.

In other words, in the second embodiment, the resistive load <NUM> inside the housing <NUM> is surrounded from three directions by the intake ports <NUM> provided on the aforementioned three outer wall surfaces of the housing <NUM>. As a result, external air taken inside the housing <NUM> from the intake ports <NUM> by the rotation of the fan motor <NUM> directly blows to the resistive load <NUM>.

As shown in <FIG>, the side wall on one end side in the longitudinal direction (one end side in the right direction in <FIG>) provided with the intake ports <NUM> in the housing <NUM> includes exhaust ports <NUM> for discharging air inside the housing <NUM> to outside. The fan motor <NUM> is arranged inside the housing <NUM> between the resistive load <NUM> and the exhaust ports <NUM>.

External air sucked from the intake ports <NUM> by the rotation of the fan motor <NUM> cools the resistive load <NUM> inside the housing <NUM>, passes the fan motor <NUM>, and is then discharged from the exhaust ports <NUM>.

Therefore, the housing <NUM> can inhibit high-temperature air deriving from heat generation of the resistive load <NUM> from staying in the housing <NUM>, and can efficiently dissipate the resistive load <NUM>.

In the housing <NUM>, since the intake ports <NUM> are provided on the aforementioned three outer wall surfaces, it is inhibited that all of the intake ports <NUM> are closed when the interlocking adapter <NUM> is attached to the electric apparatus such as the dust collector <NUM>. Therefore, according to the second embodiment, it is possible to secure a path for taking external air into the housing <NUM>, and cool the resistive load <NUM>.

In the housing <NUM>, the side wall including the exhaust ports <NUM> is provided with an insertion hole <NUM> shown in <FIG> for inserting the power cord <NUM>. A protective member <NUM> for protecting and fixing the power cord <NUM> is fitted in the insertion hole <NUM>.

The power cord <NUM> is drawn from the insertion hole <NUM> of the housing <NUM> in a state fixed to the housing <NUM> by the protective member <NUM>. Such an arrangement of the power cord <NUM> can inhibit an object existing near the exhaust port <NUM> from closing the exhaust port <NUM>.

In other words, when an object is at a position facing the exhaust port <NUM>, the object abuts on the power cord <NUM> before closing the exhaust port <NUM>. As a result, it is possible to inhibit the exhaust port <NUM> from being closed by the object.

According to the second embodiment, it is possible to secure the exhaust ports <NUM>, and exhaust paths of air inside the housing <NUM>, and inhibit cooling effect of the resistive load <NUM> from being impaired.

As shown in <FIG>, inside the housing <NUM>, the circuit board <NUM>, separate from the resistive load <NUM>, is housed. Various electronic components such as the controller <NUM> are mounted on the circuit board <NUM>. Therefore, inside the housing <NUM>, the resistive load <NUM> is coupled to the circuit board <NUM> via a lead wire <NUM> shown in a dotted line in <FIG>.

When the lead wire <NUM> is in contact with the resistive load <NUM>, coating of the lead wire <NUM> may deteriorate due to heat of the resistive load <NUM>. When the coating of the lead wire <NUM> deteriorates, the current path of the load current may contact surrounding conductors and the interlocking adapter <NUM> may fail.

In the second embodiment, as shown in <FIG>, the resistive load <NUM> is provided with a resistor 62A. The resistive load <NUM> is further provided with a heat sink 62B for heat dissipation. In the resistive load <NUM> as such, when the coating of the lead wire <NUM> deteriorates due to heat of the resistive load <NUM>, the current path of the load current may contact the heat sink 62B, and leads to failure of the interlocking adapter <NUM>.

In order to avoid such failures, inner walls of the lower case <NUM> and the upper case <NUM> facing each other are provided with a rib <NUM> and a rib <NUM>, respectively. These ribs <NUM>, <NUM> inhibit or restrain the lead wire <NUM> arranged between the circuit board <NUM> and the resistive load <NUM> from coming into contact with the resistive load <NUM>.

The ribs <NUM>, <NUM>, if formed of a single plate, can reliably inhibit or restrain the lead wire <NUM> from coming into contact with the resistive load <NUM>. However, in this case, a flow path of the air around the resistive load <NUM> is interrupted, and the cooling effect can be impaired. Therefore, each of the ribs <NUM>, <NUM> of the second embodiment is cut out in part and separated into two or more portions. With such ribs <NUM>, <NUM>, air can flow around the resistive load <NUM>, and the resistive load <NUM> can be cooled.

As shown in <FIG>, <FIG> and <FIG>, a hook <NUM> is provided on the side wall of the housing <NUM> on the opposite side of the side wall provided with the exhaust ports <NUM>. The hook <NUM> is formed into an L-shape. The hook <NUM> is fixed to the aforementioned side wall via the screw <NUM>. The screw <NUM> is configured such that the user grips the head of the screw <NUM> and rotates the screw <NUM>.

The hook <NUM> of the second embodiment includes an L-shaped plate. A first portion of this plate includes an insertion hole 112A for inserting the screw <NUM>. A second portion of the plate faces the bottom of the housing <NUM>. The insertion hole 112A may be a long hole. When the insertion hole 112A is a long hole, the first portion can be slid so as to bring the second portion into contact with the housing <NUM> or separate the second portion from the housing <NUM> in a state in which the first portion is fixed to the side wall of the housing <NUM> via the screw <NUM>.

The hook <NUM> configured as such can be fixed along the outer wall of the housing <NUM>, as shown in 14A, or can be fixed in a state pulled out from the housing <NUM>, as shown in <FIG>.

In the state in which the hook <NUM> is pulled out from the housing <NUM>, the adapter main body <NUM> may be fixed to a desired position by hooking the hook <NUM> on the hole or a protrusion. For example, as shown in <FIG>, in case that a hole <NUM> is provided by which the hook <NUM> can be hooked on the dust collector <NUM>, the adapter main body <NUM> can be attached to the dust collector <NUM> by hooking the hook <NUM> pulled out from the housing <NUM> on the hole <NUM>.

As shown in <FIG>, the screw <NUM> is screwed into a nut <NUM> provided in the housing <NUM> and fastened, so that the hook <NUM> can be fixed to the housing <NUM>.

Assuming that the nut <NUM> is provided inside the housing <NUM>, there is a possibility that the nut <NUM> may fall out inside the housing <NUM> when the screw <NUM> is detached from the nut <NUM>. When the fallen nut <NUM> moves in the housing <NUM>, the aforementioned circuit inside the housing <NUM> can be short-circuited. Therefore, it may become necessary to disassemble the housing <NUM> and perform repair work.

Thus, in the second embodiment, as shown in <FIG>, the housing <NUM> is provided with a gap <NUM> through which the nut <NUM> can be inserted from outside the housing <NUM>. The nut <NUM> can be inserted into the gap <NUM> and fixed to the housing <NUM>.

As a result, when the screw <NUM> is detached from the nut <NUM>, necessity of performing troublesome repair work such as disassembling the housing <NUM> can be eliminated or reduced.

The gap <NUM> is covered with the hook <NUM> assembled to the housing <NUM> by the screw <NUM>. Such an arrangement of the gap <NUM> can inhibit the nut <NUM> from falling out from the gap <NUM> when the screw <NUM> is detached from the nut <NUM>.

A rod-like coupling portion <NUM> for inserting the screw coupling the upper case <NUM> and the lower case <NUM> is provided on each side of the housing <NUM> interposing the screw <NUM> and the hook <NUM> therebetween. As shown in <FIG>, a gap through which a fixing band <NUM> can be inserted is formed between the housing <NUM> and each coupling portion <NUM>.

Therefore, it is possible to pass the band <NUM> having a desired length through each gap between the respective coupling portions <NUM> and the housing <NUM>. Further, it is possible to attach the adapter main body <NUM> to the electric apparatus such as the dust collector <NUM> via the band <NUM>. Moreover, since the user can use the band <NUM> to carry the interlocking adapter <NUM> to a desired place, usability of the interlocking adapter <NUM> can be improved.

As mentioned above, since the operation panel <NUM> including the LEDs of the mode indicator 84A and the error indicator 84B and the switch of the operating device <NUM> is arranged on one end side in the longitudinal direction of the housing <NUM>, the user can operate the operating device <NUM> while gripping the adapter main body <NUM>.

Operation of the operating device <NUM> by the user switches the mode setting of the interlocking adapter <NUM>, changes the lighting state of the LEDs of the mode indicator 84A, and displays the switched mode setting.

Therefore, it may be desirable for the user to grip the adapter main body <NUM> so as not to hide the LEDs of the mode indicator 84A with the hand of the user when operating the operating device <NUM>. Further, it may be desirable for the user to grip the adapter main body <NUM> so as not to hide the LED of the error indicator 84B with the hand of the user.

In consideration of the above, in the operation panel <NUM> of the second embodiment, as shown in <FIG>, the switch of the operating device <NUM> is arranged at a position close to the center in the longitudinal direction of the housing <NUM>. The LEDs of the mode indicator 84A and the LED of the error indicator 84B are arranged at end sides in the longitudinal direction of the housing <NUM>.

Therefore, the user can easily confirm the lighting state of the LEDs of the mode indicator 84A and the LED of the error indicator 84B while gripping the adapter main body <NUM>. As a result, usability of the interlocking adapter <NUM> can be improved.

The embodiments and the variations of the present disclosure have been described in the above. The present disclosure is not limited to the aforementioned embodiments or variations, and can be practiced in various modifications.

For example, in the aforementioned embodiments, one example of the electric apparatus which implements interlocking operation using the interlocking adapter <NUM> is the dust collector <NUM>, and one example of the working machine that operates in an interlocking manner with the dust collector <NUM> is the circular saw <NUM>.

However, the interlocking adapter <NUM> of the present disclosure can be utilized in the same manner as in the aforementioned embodiments in any electric apparatuses configured to detect the load current flowing through the electric outlet <NUM> and start their operations, and can cause these electric apparatuses operate in an interlocking manner with a working machine.

The working machine that operates in an interlocking manner with the electric apparatus may be an electric working machine other than the circular saw <NUM>, for example, may be a working machine driven by an engine or air motor, such as an engine cutter, and an air grinder. In either case, the working machine may be provided with a device for outputting the interlocking command signal at the time of operation.

The device for outputting the interlocking command signal may be the transmitter <NUM> for wireless signal transmission as in the aforementioned embodiments, or a device that outputs the interlocking command signal via a signal line (or wire).

Also, in the aforementioned embodiments, the mode setting is set via the operating device <NUM> operated by the user. The mode setting may be set using a mobile terminal, etc. of the user.

In the aforementioned embodiments and the variations, the load current is supplied to the resistive load <NUM>, and the electric apparatus is operated in an interlocking manner with the working machine. However, as shown in <FIG> or <FIG>, the electric load to which the load current is supplied may include a capacitive load <NUM> including a capacitor.

More specifically, the interlocking adapter <NUM> may be provided with the capacitive load <NUM> in an input path of the AC voltage from the AC plug <NUM>, and configured to supply an AC current to the capacitive load <NUM> in response to the switching part <NUM> turned on.

In the interlocking adapter <NUM> configured as such, since the AC current (reactive current) having a phase advanced by <NUM>° with respect to the AC voltage flows through the capacitive load <NUM>, loss in the electric apparatus can be reduced. Therefore, occurrence of problems such as heat generation deriving from the load current can be inhibited, and eventually the interlocking adapter <NUM> can be downsized.

In the interlocking adapter <NUM> shown in <FIG>, the switching part <NUM> is provided at the output stage of the full-wave rectifier <NUM>. The interlocking command signal from the receiver <NUM> is received by the reception input device <NUM> including the light receiving device.

When the light receiving device of the reception input device <NUM> becomes the on-state at the time of receiving the interlocking command signal, a DC voltage supplied from the control power supply <NUM> is applied to a bias circuit <NUM> coupled to the gate of the switching part <NUM> so as to turn on the switching part <NUM>, and the load current is supplied to the capacitive load <NUM>.

The bias circuit <NUM> may be provided with a voltage dividing circuit formed with a resistor R1 and a resistor R2. The control power supply <NUM> may be provided with a Zener diode ZD. The control power supply <NUM> may further include a resistor R0 through which a breakdown current flows to the Zener diode ZD by applying a reverse bias voltage from the diode <NUM> to the Zener diode ZD. The control power supply <NUM> may further include a capacitor C0 that stabilizes a power supply voltage generated by the breakdown current flowing through the Zener diode ZD.

Utilizing the capacitive load such as a capacitor as the electric load, the configuration of the interlocking adapter <NUM> can be extremely simplified.

The interlocking adapter <NUM> shown in <FIG> is provided with an oscillator <NUM>, and a resistor R2 that converts a light receiving current flowing through the light receiving device of the reception input device <NUM> into a voltage, in addition to the configuration of the interlocking adapter <NUM> shown in <FIG>.

According to the interlocking adapter <NUM> configured as such, setting an oscillation frequency of the oscillator <NUM> to a frequency higher than the frequency of the AC voltage can turn on and off the switching part <NUM> twice or more at each cycle of the AC voltage at an output from the oscillator <NUM>.

Claim 1:
An interlocking adapter (<NUM>) comprising:
a current path provided to supply a load current based on an alternating-current voltage received from an electric outlet (<NUM>) to be coupled to the interlocking adapter (<NUM>) provided in an electric apparatus (<NUM>) to be attached with the interlocking adapter;
a resistive load (<NUM>) provided in the current path;
a switch (<NUM>) provided in the current path and configured to be turned on and off, the current path being completed in response to the switch being turned on, the current path being interrupted in response to the switch (<NUM>) being turned off;
a zero-cross detector (<NUM>) for detecting a zero-cross point of the alternating-current voltage and
a controller (<NUM>) configured to turn on and off the switch (<NUM>) in synchronization with a change of the alternating-current voltage in response to reception of an interlocking command signal to be wirelessly received by the interlocking adapter from a working machine (<NUM>) to be connected to the interlocking adapter so as to supply the load current from the electric outlet (<NUM>) to the resistive load (<NUM>), the controller (<NUM>) being configured to (i) turn on the switch (<NUM>) only for a certain period after the zero-cross point every <NUM>/<NUM> cycle of the alternating-current voltage in case that the electric apparatus (<NUM>) is configured to determine whether to start interlocking operation with the working machine (<NUM>) based on the load current supplied after the zero-cross point of the alternating-current voltage and (ii) turn on the switch (<NUM>) only for a certain period before the zero-cross point every <NUM>/<NUM> cycle of the alternating-current voltage in case that the electric apparatus (<NUM>) is configured to determine whether to start the interlocking operation with the working machine (<NUM>) based on the load current supplied before the zero-cross point of the alternating-current voltage.