Electronic power equipment

An electronic power equipment, which is configured to be connected to both an AC power source and a DC power source, has a motor 14 configured to be driven by both AC power and DC power, an AC circuit 30 for supplying AC electric power to the motor 14, a DC circuit 40 for supplying DC electric power to the motor 14, switching parts RL1-RL12 for switching between the AC circuit 30 and the DC circuit 40 wherein the AC and DC circuits are insulated relative to each other, and a controller A1 configured to control the switching parts RL1-RL12, the AC circuit 30, and the DC circuit 40.

This application claims priority to Japanese patent application serial number 2015-156057, filed on Aug. 6, 2015, the contents of which are incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention generally relates to electronic power equipment capable of connecting to both an AC power source and a DC power source.

BACKGROUND ART

Japanese Laid-Open Patent Publication No. 2004-160235 discloses a related electronic power equipment, comprising an AC/DC vacuum cleaner having a DC motor as a power source. The disclosed electronic power equipment is configured such that an AC voltage supplied from a wall outlet is first converted to a DC voltage by use of an AC/DC converter before the DC voltage is supplied to a DC motor. Furthermore, the disclosed electronic power equipment is configured such that a DC voltage supplied from a battery is also supplied to the DC motor via a DC/DC converter.

The AC/DC vacuum cleaner described above includes an AC/DC converter that can convert an AC voltage to a DC voltage to supply the voltage to a motor. Generally, such an AC/DC converter includes an isolation transformer, and accordingly a vacuum cleaner having such an AC/DC converter may increase in size.

In view of the above, there is a need in the art to manufacture electronic power equipment that can be driven by both AC power and DC power and is compact in structure.

SUMMARY

In a first aspect of the present teachings, an electronic power equipment configured to be connected to both an AC power source and a DC power source is disclosed, wherein the electronic power equipment may have a motor configured to be driven by both AC power and DC power, an AC circuit for supplying AC power to drive the motor, a DC circuit for supplying DC power to drive the motor, a switching mechanism for switching between the AC circuit and the DC circuit where the respective circuits are insulated from each other, and a controller configured to control the AC circuit, the DC circuit, and the switching part.

According to the first aspect, an AC/DC converter for converting AC power to DC power in supplying the power to a DC motor, as present in the background art, may not be needed, allowing the electronic power equipment to be made in a more compact manner.

In another aspect of the present teachings, the switching mechanism may switch between the AC circuit and the DC circuit using a plurality of relay switches, each having a mechanical contact. This mode of switch and circuit construction enables, the AC circuit and the DC circuit can to be easily switched from one to the other, where both circuits are insulated from each other, in a simple structure.

In another aspect of the present teachings, the switches may be arranged in both a positive line and a negative line in the AC circuit and both a positive line and a negative line in the DC circuit. Applicant defines positive line and negative line of an AC circuit in this application to be the lines of the AC circuit connecting to the positive or negative terminals of a motor, respectively, where the motor terminals correspond to the positive and negative lines of a DC circuit to which the motor is also connected (e.g. inFIG. 6, 31is the positive line of the AC circuit, connected to the positive terminal of the motor, while32is the negative line of the AC circuit, connected to the negative terminal of the motor, where the terminals of the motor correspond to the DC circuit40to which it is also connected). In the present teachings, in accordance with the definition, the positive line and the negative line in the AC circuit, as well as the positive line and the negative line in the DC circuit may be connected to the motor. Because of the presence of switches along the circuits, insulation properties between the AC circuit and the DC circuit can be easily and reliably obtained.

In another aspect of the present teachings, a plurality of switches may be arranged in series in both the positive line and the negative line in the AC circuit, and also a plurality of switches may be arranged in series in both the positive line and the negative line in the DC circuit. Because of this series arrangement of switches, a predetermined insulation distance between the AC circuit and the DC circuit can be easily and reliably obtained.

In another aspect of the present teachings, the controller may be configured to perform a running test of the switches in the positive line and the negative line in the DC circuit before driving the motor for the first time after the electronic power equipment is powered on. Because of this controller configuration, reliability of the switching mechanism can be improved.

In another aspect of the present teachings, the controller may be configured to perform a running test of the switches in the positive line and the negative line in the DC circuit when the switching mechanism switches between the AC circuit and the DC circuit. Because of this controller configuration, reliability of the switching mechanism can be improved.

In another aspect of the present teachings, the controller may be configured to supply power to the motor from the AC power source when the electronic power equipment is connected to both the AC power source and the DC power source. Because of this controller configuration, consumption of the DC power source, e.g. batteries, can be suppressed.

In another aspect of the present teachings, the controller may be configured to stop driving of the motor when the AC power source is disconnected from the electronic power equipment. Because of this controller configuration, the motor is prevented from being driven by the DC power source, e.g. batteries, when the AC power source is disconnected (e.g. a plug supplying AC power is pulled out of a wall outlet). Thus, inadvertent decrease of battery life is prevented.

In another aspect of the present teachings, both the AC circuit and the DC circuit may each include at least one adjusting element for adjusting electric power supplied to the motor. Furthermore, the controller may switch the mechanical contacts of the relay switches from their pre-existing state to the opposite state (e.g. from closed to open or vice versa) while switching off the adjusting element. Because of this mode of switching off the adjusting element, current will not flow regardless of whether the contacts of the switches are opened and/or closed, and thus the contacts of the switches can be reliably protected.

In another aspect of the present teachings, the electronic power equipment may further include interlock circuits that prevent the mechanical contacts of the relay switches in the DC circuit from closing when the mechanical contact of the relay switches in the AC circuit are closed. Because of this construction, even if the controller malfunctions, a failure such that current flows simultaneously both in the AC circuit and the DC circuit may not occur.

In another aspect of the present teachings, there is i) at least one relay switch in the positive and negative line, respectively, in the AC circuit, and ii) at least one relay switch in the positive and negative line, respectively, in the DC circuit, wherein iii) interlock circuits (each interlock circuit corresponds to an AC switch and a DC switch pairing, where the AC and DC switches are located on the same type of line (positive or negative) in the AC and DC circuit, respectively) and corresponding switches of the positive and negative lines of the AC and DC circuits may be located on the same electronic circuit board. Because of this construction, wirings of the interlock circuit may not be crossed between electrical circuit boards, and accordingly, disconnection of the wirings of the interlock circuit can be prevented. Thus, reliability of the interlock circuit can be maintained.

In another aspect of the present teachings, the electronic power equipment may further include a main switch configured to switch on and off, collectively, the positive and negative lines in the AC circuit and a DC line connected to the DC power source.

According to the present teachings, an electronic power equipment that can be driven by both AC power and DC power can be manufactured in a compact structure.

DETAILED DESCRIPTION OF EMBODIMENTS

The detailed description set forth below, when considered with the appended drawings, is intended to be a description of exemplary embodiments of the present invention and is not intended to be restrictive and/or to represent the only embodiments in which the present invention can be practiced. The term “exemplary” used throughout this description means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other exemplary embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments of the invention. It will be apparent to those skilled in the art that the exemplary embodiments of the invention may be practiced without these specific details. In some instances, well-known structures, components and/or devices are shown in block diagram form in order to avoid obscuring significant aspects of the exemplary embodiments presented herein.

Hereinafter, an electronic power equipment according to one exemplary embodiment of the present teachings will be described with reference toFIGS. 1 to 10. The electronic power equipment according to the embodiment may be a dust collector10that can suck (collect) dusts and/or debris generated when a material to be cut is processed using a tool. The front, rear, left, right, upper, and lower sides of the drawings correspond to the front, rear, left, right, upper, and lower sides of the dust collector10.

As shown inFIG. 1, the dust collector10may generally include a dust collector main body12and a suction hose13that is connected to a dust collection port12hof the dust collector main body12. The dust collector main body12may be configured such that airflow is generated by a fan (not shown) that is rotated by an electric motor14(refer to an electric circuit diagram ofFIG. 6) and outside air including dust and/or debris can be sucked from the dust collection port12hvia the suction hose13due to the airflow. Furthermore, the outside air including the dust and/or debris may be passed through a filter (not shown) provided in the dust collector main body12to separate the dust and/or debris from the air, which may be discharged from an exhaust port (not shown). Because of this configuration, dust and/or debris sucked from the dust collection port12hmay be collected inside the dust collector main body12. As shown in the electric circuit diagram ofFIG. 6, the dust collector main body12may be configured such that the motor14is driven by an AC power source from a wall outlet11or a DC power source from batteries26. The motor14may be a universal motor that can be driven by both an AC power source and a DC power source.

As shown inFIG. 2, the dust collection port12hmay be located at a center lower part of the front face of the dust collector main body12. Furthermore, a main power switch SW1, a speed adjustment volume22, and a battery remaining display24may be provided above the dust collection port12h.Furthermore, a drive switch SW2for driving and stopping the motor14may be provided at an upper part of the front face of the dust collector main body12. As shown inFIGS. 2 to 4, a top plate12uof the dust collector main body12may include a top plate fixing part12slocated on a front side thereof (refer toFIG. 2), and a rotary lid part12blocated on a rear side thereof and configured to be rotated upward with respect to the top plate fixing part12s(refer toFIGS. 3 and 4). Furthermore, as shown inFIGS. 4 and 5, the rotary lid part12bof the top plate12umay be configured to open and close a battery compartment B that is formed in an upper part of the back of the dust collector main body12.FIG. 5shows the dust collector main body12in a state where the top plate12uetc. is removed therefrom.

As shown inFIGS. 4 and 5, a pair of battery connection receptacles18may be provided on a front side vertical wall of the battery compartment B of the dust collector main body12. The battery compartment B may be configured such that batteries26can be connected by sliding the batteries26in a downward direction, into the receptacles. DC power may be supplied to the dust collector main body12in a state where batteries26are connected to the pair of the battery connection receptacles18. Furthermore, when the batteries26are connected to the battery connection receptacles18, waterproofing of the batteries26may be achieved by closing the rotary lid part12bof the top plate12u.

As shown inFIG. 5, an upper-open-type battery holding case19that can hold two auxiliary batteries26may be provided below the battery compartment B of the dust collector main body12. Furthermore, a power cord16with a plug may be provided on a right surface of the rear part of the dust collector main body12. When the plug17of the power cord16is connected to a wall outlet11(refer toFIG. 6), AC power may be supplied to the dust collector main body12.

As shown inFIG. 6, an electrical circuit of the dust collection main body12may include an AC circuit30for driving the motor14, a DC circuit40for driving the motor14, a plurality of relay switches RL1to12used for switching between the AC circuit30and the DC circuit40, protection circuits51to56, and a microcomputer controller A1, etc. Furthermore, the AC circuit30, the DC circuit40, the plurality of relay switches RL1to12, the protection circuits51to56, and the microcomputer controller A1, etc. may be mounted on an electrical circuit divided into three boards, i.e., a first electrical circuit board K1, a second electrical circuit board K2, and a third electrical circuit board K3.

As shown inFIG. 6, the AC circuit30for driving the motor14may supply AC power, which is supplied to the dust collector main body12via the plug17of the power cord16from the wall outlet11, to the motor14. The AC circuit30may include a positive line31connected to a positive terminal of the motor14and a negative line32connected to a negative terminal of the motor14(where positive and negative line in the context of the AC circuit is defined above). Furthermore, both the positive line31and the negative line32may each be connected to the plug17of the power cord16via the main power switch SW1provided on a front surface of the dust collector main body12. A bidirectional thyristor Q13capable of adjusting electric power supplied to the motor14may be provided at a secondary side of the main power switch SW1in the positive line31of the AC circuit30.

As shown inFIG. 6, in the positive line31of the AC circuit30, a first relay switch RL7, a second relay switch RL8, and a third relay switch RL9may be located in series between the bidirectional thyristor Q13and the positive terminal of the motor14. Furthermore, in the negative line32of the AC circuit30, a fourth relay switch RL10, a fifth relay switch RL11, and a sixth relay switch RL12may be located in series between the secondary side of the main power switch SW1and the negative terminal of the motor14. The first relay switch RL7to the sixth relay switch RL12may be structurally configured such that each mechanical contact of the relays RL7to RL12can be opened and closed by an electromagnetic force generated by a coil mounted on each relay. A regulated power converter34that may convert an AC voltage to a DC voltage may be provided in the AC circuit30in order to obtain a constant voltage power source from the AC circuit. The DC voltage produced by the regulated power converter34may be supplied to power a microcomputer controller A1. Furthermore, a voltage signal (detection signal) of the regulated power converter34, reflecting the converted AC voltage, may be input to the microcomputer controller A1. Because of this signal, the microcomputer controller A1is able to detect that AC power has been supplied to the dust collector main body12.

As shown inFIG. 6, the DC circuit40for driving the motor14may supply DC power from the batteries26, which are supplied to the dust collector main body12via the battery connection receptacles18, to the motor14. The DC circuit40may include a positive line41connected to the positive terminal of the motor14and a negative line43connected to the negative terminal of the motor14. In the positive line41, a fuse F1may be located near the battery connection parts18, and a control line41ymay branch from the positive line41at a secondary side of the fuse F1. The control line41ymay be connected to a regulated power converter44via the main power switch SW1, and a DC voltage produced by the regulated power converter44may be supplied to the microcomputer controller A1etc. The regulated power converter34in the AC circuit30may be connected to an anode of a first diode, and the regulated power converter44in the DC circuit40may be connected to an anode of a second diode. A cathode of the first diode and a cathode of the second diode may then be connected to each other to supply to the microcomputer controller A1. Because of this construction, the microcomputer controller A1can operate by either AC power or DC power being supplied. The control line41ymay correspond to a power supply line of the present disclosure.

As shown inFIG. 6, in the positive line41of the DC circuit40, a first FET (field effect transistor) Q8, which is a switching element, may be located downstream of the branch point between the control line41yand the positive line41, and a stepup converter41pmay be located downstream of the first FET Q8. The stepup converter41pmay boost a voltage of the battery26to a suitable voltage for driving the motor14. An output voltage of the stepup converter41pmay be set lower than an effective value of the AC voltage. Furthermore, in the positive line41, a first relay switch RL1, a second relay switch RL2, and a third relay switch RL3may be located in series between the stepup converter41pand the positive terminal of the motor14. In the negative line43of the DC circuit40, a second FET Q11, which is an adjusting clement for adjusting electric power that is supplied to the motor14, may be located on a side of the battery connection receptacles18. Furthermore, a fourth relay switch RL4, a fifth relay switch RL5, and a sixth relay switch RL6may be located in series between the second FET Q11and the negative terminal of the motor14. The first relay switch RL1to the sixth relay switch RL6may have the same structure as RL7to RL12of the AC circuit, and may also be structurally configured such that each mechanical contact of each relay switch can be opened and closed by an electromagnetic force generated by a coil mounted on each relay switch.

In the DC circuit40, a voltage application part46that can apply a voltage (+12V) for performing a relay running test may be located between the stepup converter41pand the first relay switch RL1in the positive line41. Furthermore, a comparator A8, which compares a voltage of the negative line43(a voltage for checking a relay operation) with a reference voltage (Vs), may be located between the sixth relay RL6and the second FET Q11in the negative line43. An output signal of the comparator A8may be input to the microcomputer controller A1. The reference voltage (Vs) may be between 0V to 12 V, (e.g. 3V).

The microcomputer controller A1can switch between the DC circuit40and the AC circuit30by operating the relay switches RL1to RL12, and also control driving of the motor14by operating the bidirectional thyristor Q13, the first FET Q8, and the second FET Q11, etc. Specific output terminals of the microcomputer controller A1may be electrically connected to the coils of the relay switches RL1to RL12. Furthermore, a signal of the drive switch SW2for driving and stopping the motor14and a signal of the speed adjustment volume22may be input to the microcomputer A1. Furthermore, the microcomputer controller A1may be configured to perform a running test of relay switches RL1to RL6by utilizing the voltage application part46and the comparator A8in the DC circuit40. Furthermore, the microcomputer controller A1may be configured to monitor the voltage of the batteries26and display a resulting battery remaining capacity on a battery remaining capacity display24. The battery remaining capacity display24may be configured such that the battery remaining capacity can be shown for a predetermined period of time when a confirmation switch SW3is pressed while the battery26is connected. Even when the motor14is driven by the AC power source, a remaining capacity of the batteries26can be displayed for a predetermined period of time if the confirmation switch SW3is pressed and the batteries26are connected through the battery connection receptacles18. In this way, the microcomputer controller A1may correspond to a control section of the present teachings, and the relay switches RL1to RL12may correspond to a switching mechanism, as described above.

Protection circuits51to56may be interlock circuits that are configured such that even if the microcomputer controller A1malfunctions, the contacts of the first relay switch RL1to the sixth relay switch RL6in the DC circuit40may not be closed (where being closed would allow current to flow) when the first relay switch RL7to the sixth relay switch RL12in the AC circuit30are closed. The protection circuits51to56, acting as interlock circuits, may be configured not to close the contacts of the relay switches RL1to RL12by preventing a current from flowing through the coils of the relays RL1to RL12. The protection circuits51to56may comprise a first protection circuit51, a second protection circuit52, a third protection circuit53, a fourth protection circuit54, a fifth protection circuit55, and a sixth protection circuit56. As shown inFIG. 6, the first protection circuit51may serve as an interlock circuit between the first relay switch RL7in the AC circuit30and the first relay switch RL1in the DC circuit40. Similarly, the second protection circuit52may serve as an interlock circuit between the second relay switch RL8in the AC circuit30and the second relay switch RL2in the DC circuit40, . . . , and the sixth protection circuit56may serve as an interlock circuit between the sixth relay switch RL12in the AC circuit30and the sixth relay switch RL6in the DC circuit40.

The first electrical circuit board K1, the second electrical circuit board K2, and the third electrical circuit board K3may comprise electrical circuit boards on which the electrical components of the dust collector main body12are mounted. Considering an installation space, the circuit may be divided into three boards. As shown inFIG. 6, the first FET Q8, the second FET Q11, the stepup converter41p,and the comparator A8, etc. may be mounted on the first electrical circuit board K1. As shown inFIG. 5, the first electrical circuit board K1may be attached and/or erected along a right side wall in the housing of the dust collector main body12. Furthermore, a heat sink61of the first FET Q8, and the second FET Q11may protrude to a central area of the housing.

Furthermore, as shown inFIG. 6, i) the microcomputer controller A1, ii) the regulated power converter44, the voltage application part46, the first relay switch RL1in the DC circuit, the sixth relay switch RL6in the DC circuit40, and iii) the regulated power converter34, the bidirectional thyristor Q13, the first relay switch RL7in the AC circuit, and the sixth relay switch RL12in the AC circuit, etc. may be mounted on the second electrical circuit board K2. Furthermore, the first protection circuit51and the sixth protection circuit56may be mounted on the second electrical circuit board K2. As shown inFIG. 5, the second electrical circuit board K2may be installed in the right and left direction on a front side of the housing of the dust collector main body12. Furthermore, a heat sink62of the bidirectional thyristor Q13may be installed on the rear left side of the second electrical circuit board K2.

Furthermore, as shown inFIG. 6, i) the second relay switch RL2, the third relay switch RL3, the fourth relay switch RL4, and the fifth relay switch RL5, wherein these switches are in the DC circuit40, and ii) the second relay switch RL8, the third relay switch RL9, the fourth relay switch RL10, and the fifth relay switch RL11, wherein these switches are in the AC circuit30, may all be mounted on the third electrical circuit board K3. Furthermore, the second protection circuit52, the third protection circuit53, the fourth protection circuit54, and the fifth protection circuit55may be also mounted on the third electrical circuit board K3. As shown inFIG. 5, the third electrical circuit board K3may be installed in the rear part of the housing of the dust collector main body12, in more detail, on an upper front side of the pair of the battery connection receptacles18, in its horizontal state. As described above, the relay switches RL2to RL5in the DC circuit40, the relay switches RL8to RL11in the AC circuit30, and the second protection circuit52to the fifth protection circuit55may be installed on the same electrical circuit board, and accordingly wirings of the protection circuits52to55(interlock circuits) may not be crossed between the electrical boards, which can prevent disconnection of the wirings.

Next, how to operate the dust collector10will be explained below according to flowcharts shown inFIGS. 7 to 10. Processes according to the flowcharts shown inFIGS. 7 to 10may be executed at predetermined times according to a program stored in the memory of the microcomputer controller A1, which may be a non-transient form of memory such as a ROM, a PROM, an EPROM, an EEPROM, etc. At first, a case will be explained below where not only the batteries26are connected to the pair of the battery connection receptacles18of the dust collector main body12but also the plug17of the power cord16is connected to the wall outlet11. When the main power switch SW1is switched on in this state, electric power from the regulated power converter34in the AC circuit30and also electric power from the regulated power converter44in the DC circuit40may be supplied to power the microcomputer controller A1. At this time, a detection signal, reflecting the converted AC voltage, from the regulated power converter34in the AC circuit30may be input to the microcomputer A1, and accordingly the microcomputer controller A1may detect that AC power is supplied to the dust collector main body12. In the program in the memory of microcomputer controller A1, processes may be performed such that AC power is prioritized.

When the microcomputer A1is run, a procedure below may be performed at intervals of predetermined time as shown in S101ofFIG. 7. In S102a watch dog timer may be cleared. The watch dog timer may be configured such that the microcomputer controller A1may be reset unless the timer is cleared within a predetermined time. Next, in S103, an ON/OFF operation of the drive switch SW2for driving and stopping the motor14and an ON/OFF operation of the confirmation switch SW3of the battery remaining capacity display24may be checked. Then, in S104, a processing to convert an analog signal, such as a voltage signal of the batteries26and a signal from the speed adjustment volume22, to a digital signal, may be performed. In S105, an abnormal voltage and/or current of the battery26may be confirmed. Next, in S106, a judgment of the power source, i.e., which of the DC or AC power source is being used, may be performed. Then, in S107, a relay control processing may be performed.

The relay control processing may be executed according to the flowcharts inFIGS. 8 and 9. When the drive switch SW2of the motor14is switched on (YES in S201ofFIG. 8), a relay failure flag may be confirmed in S202. When the drive switch SW2is switched on for the first time after the main power switch SW1is switched on, a relay failure judgment may not have been performed. Thus, a judgment in S202may be YES, and then in S203a judgment about whether the power source has been changed or not may be performed. If the power source has not been changed since the drive switch SW2is switched on (NO in S203) then it may be confirmed in S204whether there is an OFF state for each adjusting element (the first FET Q8, the second FET Q11, and the bidirectional thyristor Q13). If the adjusting elements are confirmed to be in an OFF state (YES in S204), and a relay normal flag is not set (NO in S205), then in S207, a relay failure confirmation processing may be performed.

In the relay failure confirmation processing, operations of the first relay switch RL1to the sixth relay switch RL6located in the DC circuit40may be checked according to the flowchart shown inFIG. 9. At first, as shown inFIG. 9, in S301, it may be checked at a predetermined time point whether an operation of the second FET Q11has been confirmed. If an operation of the second FET Q11has not been confirmed at the time point, (NO in S301), then each contact of the first relay RL1to the sixth relay RL6may be closed (switched on) in S302. After a predetermined time is passed (YES in S303), a voltage is applied to the relay switches RL1to RL6, the motor14, and the negative line43from the voltage application part46(+12 V), and may be checked via a comparator A8by comparison to a reference voltage. By confirming the voltage of the voltage application part46(+12 V) in the comparator A8(H), it may be confirmed whether each contact of the first relay switch RL1to the sixth relay switch RL6is correctly closed and the second FET Q11is correctly switched off. In this case, a judgment may be YES in S304, and then an operation confirmation flag of the second FET Q11(Q11confirmation flag) may be set. When the voltage of the voltage application part46is not confirmed in the comparator A8(L), it may be judged that any contact(s) of the relay switches RL1to RL6may not be closed, and a relay failure flag may be set in S306. Then, because a failure has been confirmed, all contacts of the relays RL1to RL6may be opened (switched off), which means that the motor14cannot be energized.

When the relay failure confirmation processing is performed at the next predetermined time interval at S301, the judgment may now be YES in S301if the Q11confirmation flag has been set in S305as performed at the previous time point, as explained above. In this case, in S311, it may be confirmed that an operation of the first relay RL1has been performed. At the current time point at which S311is checked, if the operation of the first relay RL1has not been performed (NO in S311), then, in S312, a contact of the first relay RL1may be opened (switched off) while the second relay switch RL2to the sixth relay switch RL6are closed (switched on). Then, after a predetermined time is passed (YES in S313), a voltage is applied to the positive line41, the motor14, and the negative line43by the voltage application part46, to test whether the relay switch contacts have correctly opened in the comparator A8, wherein the comparator reading should be low. When the voltage of the voltage application part46is confirmed to be low in the comparator A8(L), it may be confirmed that a contact of the first relay RL1is correctly opened. In this case, a judgment may be YES in S314, and then in S315, an operation confirmation flag of the first relay RL1(RL1confirmation flag) may be set. However, if the voltage of the voltage application part46is confirmed to not be low in the comparator A8(H), it may be judged that a contact of the first relay switch RL1has not been opened. Thus, in S316, a relay failure flag may be set. Furthermore, because a failure has been confirmed, all contacts of the relay RL1to RL6may be opened in S318, which means that the motor14cannot be energized. Similar processing may be performed with respect to the second relay switch RL2to the sixth relay switch RL6(refer to S361to S368). InFIG. 9, failure judgments with regard to the second relay RL2to the sixth relay RL6are omitted. When all relays RL1to RL6are confirmed to be correctly operated, a relay normal flag may be set in S367. Next, in S369, all contacts of the relays RL1to RL12may be temporarily opened (switched off) and the relay failure confirmation processing may be finished.

InFIG. 9, when a predetermined time has not passed in S303, S313, and S363after relay operations are performed in S302, S312, and S362, the relay failure confirmation processing of step S207may be finished, meaning the procedure may be returned to S207inFIG. 8. This is because it may take time to close contacts of the relays after each coil of the relays is energized and it may be necessary to wait to stabilize closing and opening states of the contacts.

When the relay failure confirmation processing (the processing shown inFIG. 9) is finished, a procedure may return to S207inFIG. 8, and furthermore return to S107inFIG. 7. Next, a motor control processing may be executed in S108. The motor control processing may be executed according to a flowchart shown inFIG. 10. In S400ofFIG. 10, it may be confirmed whether the drive switch SW2is switched on. As described earlier, if the drive switch SW2has been switched on (YES in S400), then a changing of the power source (AC or DC) may be confirmed in S401. If the power source has not been changed (NO in S401), and then the relay normal flag may be checked in S402. If the relay normal flag has been set (YES in S402), then in S403it may be checked whether the relay switches are closed (switched on). At a time point S403, if the relay switches RL1to RL12are detected as opened and not having been switched on (NO in S403), the procedure may return to S108inFIG. 7, and then a display processing in S109and a sleep processing in S110may be executed in turn.

Then, after the processing in S101to S106may be executed again, the relay control processing in S107may be executed again. The procedure may proceed to S201inFIG. 8. At this time point if the confirmations at the various stops are YES in S201, YES in S202, NO in S203and YES in S204, then in S205, it may be confirmed whether the first relay switch RL1to the sixth relay switch RL6are normal. If so, because all of the first relay RL1to the sixth relay switches RL6are normal (YES in S205), a relay ON control processing may be executed (S206). Then, at that time point, both AC power and DC power are supplied. As described earlier, in the program stored in the memory a microcomputer controller A1, processes may be performed such that AC power is prioritized, and accordingly each contact of the first relay RL7to the sixth relay RL12in the AC circuit30may be closed (switched on) by the relay ON control processing.

Next, the procedure may proceed to S108in which the motor control processing shown inFIG. 10may be executed. InFIG. 10, because each contact of the first relay RL7to the sixth relay RL12of the AC circuit may be closed, the confirmations of the steps may yield results of YES in S400, NO in S401, YES in S402, and YES in S403. If so, then in S404, it may be confirmed whether a predetermined time is passed since each contact of the first relay RL7to the sixth relay RL12has been closed. When the predetermined time is passed (YES in S404), it may be confirmed whether the AC power source is selected. At this time point, if AC power source is selected, then AC control processing may be executed in S406. In more detail, in S406, the microcomputer controller A1may control a rotating speed of the motor14by operating the bidirectional thyristor Q13to adjust electric power supplied to the motor14based on the speed adjustment volume22. Because of this construction, a suction force of the dust collector10can be adjusted. In this way, the contacts of the first relay RL7to the sixth relay RL12may be closed before the bidirectional thyristor Q13being operated, and thus because of this sequence of operations current may not be flowed even when the contacts of the first relay RL7to the sixth relay RL12are closed. Accordingly, the contacts of the relays can be protected.

In the motor control processing, when the drive switch SW2of the motor14is switched off, a judgment in S400ofFIG. 10may be NO, and it may be confirmed in S410whether the AC power source is selected. At that time point, if the AC power source is selected (YES in S410), then an AC control stop processing may be performed in S411. In this processing, the microcomputer controller A1may switch off the bidirectional thyristor Q13to stop the motor14. Furthermore a judgment in S201in the relay control processing shown inFIG. 8may be NO, and then in S212, it may be confirmed whether the switching and/or adjusting elements (the first FET Q8, the second FET Q11, an FET in the stepup converter41p,and the bidirectional thyristor Q13) are switched off. If the adjusting elements may be switched off (YES in S212), then in S213, all of the first relay RL7to the sixth relay switches RL12of the AC circuit30may be switched off. The first relay RL1to the sixth relay switches RL6of the DC circuit40, as mentioned above, may be retained in a OFF state. Furthermore, the power source may not be switched from the DC power source to the AC power source (NO in step S214), the procedure may proceed to S108shown inFIG. 7. As described earlier, all relays may be switched off, and thus the motor14may be retained in a stopped state. Furthermore, abnormalities during a driving or stopping of the motor14and a battery remaining capacity etc. may be displayed in S109shown inFIG. 7. Furthermore, when a predetermined time has passed after the motor14is stopped, a sleep processing (S110shown inFIG. 7) in which power consumption of the regulated power converters34and44or the microcomputer controller A1is suppressed may be performed. When the AC power source is selected, the sleep processing may not be performed.

Next, when the drive switch SW2of the motor14is switched on again, a judgment in S201in the relay control processing shown inFIG. 8may be YES. Then, if the confirmations of steps S202and S203result in YES in S202and NO in S203, then in S204it may be confirmed whether the switching and/or adjusting elements (the first FET Q8, the second FET Q11, the FET in the stepup converter41p,and the bidirectional thyristor Q13) are switched off. If the adjusting elements are switched off (YES in S204), then the relay normal flag is set (YES in S205), and accordingly, relay ON control processing may be executed (S206). In S206, an operation to close the contacts of the first relay RL1to the sixth relay RL6switches located in the AC circuit30may be performed. Then, the motor control processing may be executed in S108shown inFIG. 7. In the motor control processing, if the various confirmations are YES in S400, NO in S401, YES in S402, YES in S403, and YES in S404, then in S406, an AC control processing may be executed. That is, a motor control processing may be executed by the AC circuit30. In this way, when the motor14is driven in without changing the power source, the relay failure confirmation processing (S207shown inFIG. 8;FIG. 10) may not be performed.

Next, an explanation will be made about a case where the batteries26are attached to the dust collector main body12, the motor14of the dust collector main body14is driven by the AC circuit30(the drive switch SW2is switched on), and the plug17of the power cord16is pulled out of the wall outlet11. In this case, the microcomputer A1may not detect the detection signal from the regulated power converter34located in the AC circuit30. Accordingly, the microcomputer A1may judge that power supply from the AC power source has stopped. That is, in the motor control processing shown inFIG. 10, a judgment whether the power source is changed may be YES in S401. Then, in S410, it may be confirmed whether the AC power source had been used. Because the AC power source had been used until then, this would result in a confirmation of YES in S410, where then in S411, an AC control stop processing may be executed. In more detail, the microcomputer controller A1may switch off the bidirectional thyristor Q13to stop the motor14. The drive switch SW2of the motor14has been switched on, and accordingly a judgment in S201shown inFIG. 8may be YES. Furthermore, the relays have no failure (YES in S202), and the power source has been changed (YES in S203). Then, in S210, a relay normal flag and a relay failure flag may be cleared, and in S211, a second FET Q11confirmation flag and a RL1to RL6confirmation flag may be cleared.

Next, in S212, it may be confirmed whether the switching and/or adjusting elements (the first FET Q8, the second FET Q11, the FET in the stepup converter41p,and the bidirectional thyristor Q13) are switched off. The bidirectional thyristor Q13may be switched off as described above, and accordingly a judgment in S212may be YES. If so, then in S213, all relays (the first relay RL7to the sixth relay switch RL12, and the first relay RL1to the sixth relay switch RL6) may all be switched off. Furthermore, the power source may be changed from the AC power source to the DC power source, and accordingly a judgment in S214may be NO. Then, a procedure may proceed to the motor control processing in S108shown inFIG. 7. As described earlier, all of the relays may be switched off, and accordingly the motor14may be retained in the stopped state.

Next, when the drive switch SW2of the motor14is switched on in a state where the battery26is attached to the dust collector main body12and the plug17of the power cord16is pulled out of the wall outlet11, a judgment in S201shown inFIG. 8may be YES. Furthermore, the relays may have no failure (YES in S202), and the power source has not been changed (NO in S203). If so, then, in S204, it may be confirmed whether the switching and/or adjusting elements (the first FET Q8, the second FET Q11, the FET of the stepup converter41p,and the bidirectional thyristor Q13) are switched off. The adjusting elements may be switched off (YES in S204), and the relay normal flag may be cleared (NO in S205). In this case, then, in S207, the relay failure confirmation processing, which is shown inFIG. 9, may be executed. When it is confirmed that the relays are normal in the relay failure confirmation processing, then a judgment in S205shown inFIG. 8may be YES, and the relay ON control processing may be executed in S206. In the relay ON control processing, the contacts of the first relay RL1to the sixth relay switch RL6located in the DC circuit may be closed.

Next, the motor control processing (S108shown inFIG. 7;FIG. 10) may be executed. In the motor control processing shown inFIG. 10, if the confirmations for the various steps are YES in S400, NO in S401, YES in S401-S404, and No in S405because the DC power source at the current time point, then, in S407, a DC control processing may be executed. In the DC control processing, the motor control may be performed by the DC circuit40. In more detail, the microcomputer controller A1may switch on the first FET Q8, and then activate the stem converter41pby outputting a control signal to the stepup converter41p.Furthermore, the microcomputer controller A1may control a rotating speed of the motor14by switching on and off the second FET Q11to adjust electric power supplied to the motor14based on the speed adjustment volume22. To summarize, when the plug17of the power cord16is pulled out of the wall outlet11while the motor14is driven by the AC circuit30with the battery26attached to the dust collector main body12, the motor14may not be driven unless the drive switch SW2of the motor14is switched on again, in which case the motor control processing is performed.

Next, an explanation will be made about a case where the plug17of the power cord16is inserted in the wall outlet11while the motor control is performed by the DC circuit40(the drive switch SW2is switched on). As described earlier, per the program stored in the memory of microcomputer controller A1, processes may be performed such that AC power is prioritized. In this case, in S401in the motor control processing shown inFIG. 10, it may be confirmed whether the power source is changed, and the judgment may be YES, due to the power cord being inserted into the wall outlet. Then, in S410, it may be confirmed whether the AC power source had been used. The DC power source had been used until the current time point, which would thus result as NO in S410, whereby then in S412, a DC control stop processing may be performed. In more detail, the microcomputer controller A1may switch off the second FET Q11to stop the motor14. Next, the microcomputer controller A1may output a stop signal to the stepup converter41pto stop before switching off the first FET Q8. The drive switch SW2of the motor14has been switched on as described above (an ON signal from the drive switch SW2has been retained), and accordingly, a judgment in S201shown inFIG. 8may be YES. If the relays have no failure (YES in S202), and the power source is changed (YES in S203), then in S210the relay normal flag and the relay failure flag may be cleared. Then, in S211the second FET Q11confirmation flag and the RL1-RL6confirmation flag may be cleared.

Next, in S212, it may be confirmed whether the switching and/or adjusting elements (the first FET Q8, the second FET Q11, the FET of the stepup converter41p,and the bidirectional thyristor Q13) are switched off. If the first FET Q8and the second FET Q11are be switched off, then accordingly, a judgment in S212may be YES. Then, in S213, all relays (the first relay RL7to the sixth relay switch RL12, and the first relay RL1to the sixth relay switch RL6) may be switched off. Furthermore, the power source may be changed from the DC power source to the AC power source, and accordingly a judgment in S214may be YES. As previously described, the second FET Q11confirmation flag and the RL1-RL6confirmation flag may be cleared, and thus a judgment in S205may be NO, and then in S207(andFIG. 9) the relay ON control processing may be executed. When it is confirmed that the relays are normal in the relay ON control processing (YES in S205shown inFIG. 8), the relay ON control processing (S206) may be executed. In the relay ON control processing, the contacts of the first relay RL7to the sixth relay switch RL12located in the AC circuit may be closed.

Next, the motor control processing may be executed based on S108shown inFIGS. 7 and 10. In the motor control processing shown inFIG. 10, if the results of the various confirmations are YES in S400, NO in S401, YES in S402to S404, and YES in S405because the AC power source is being used at the current time point, then, in S406, the AC control processing may be executed. That is, the microcomputer controller A1may control rotating speed of the motor14by operating the bidirectional thyristor Q13to adjust electric power supplied to the motor14based on the speed adjustment volume22. To summarize, when the plug17of the power cord16is inserted in the wall outlet11while the motor14is driven by the DC circuit40, the motor control processing may be executed by the AC circuit after checking the first relay RL1to the sixth relay switch RL6.

According to the present teaching of the dust collector10, the motor14may be configured to drive by both the AC power source and the DC power source. Furthermore, the AC circuit30in which AC power is supplied to the motor14and the DC circuit40in which DC power is supplied to the motor14may be configured to be changed in an insulated state relative to each other through the operations of the microcomputer controller A1, the first relay switch RL1to the sixth relay switch RL6of the DC circuit, and the first relay switch RL7to the sixth relay switch RL12of the AC circuit. Because of this construction, an AC/DC converter etc., which often includes an isolation transformer, as described above, for converting AC power to DC power to supply power to the motor is not needed, and thus the dust collector10can be made in a substantially more compact structure. Furthermore, because the first relay switch RL1to the sixth relay switch RL6, and the first relay switch RL7to the sixth relay switch RL12are used, the AC circuit30and the DC circuit40can be easily and reliably changed relative to each other to supply power to the motor in an insulated state.

Furthermore, in the AC circuit30, the first relay switch RL7to the sixth relay switch RL12may be arranged such that the relays RL7-RL9are located in the positive line31and the relays RL10-RL12are located in the negative line32(where the positive line and the negative line in the AC circuit are as defined above). Furthermore, in the DC circuit40, the first relay switch RL1to the sixth relay switch RL6may be arranged such that the relays RL1-RL3are located in the positive line41and the relays RL4-RL6are located in the negative line43. Because of this construction, an insulated state between the AC circuit30and the DC circuit40can be easily and reliably obtained. According to the dust collector10of the present teaching, the dust collector and its controlled components, along with microcomputer A1as described above, may be configured such that the operations of the first relay switch RL1to the sixth relay switch RL6in the DC circuit40are checked before the motor14is driven for the first time after the main power switch SW1is switched on. Furthermore, the dust collector also may be configured such that the operations of the first relay switch RL1to the sixth relay switch RL6in the DC circuit40are checked when switching between the AC circuit30and the DC circuit40is performed. Because of this configuration, reliability of the switching between AC power and DC power can be improved.

Furthermore, in a case where the plug17of the power cord16is pulled out of the wall outlet11(i.e., the AC power source is disconnected) with the battery26connected, the microcomputer A1may switch off the bidirectional thyristor Q13to stop driving of the motor14. Because of this construction, for example, the motor14may not be driven by the battery26with the plug17pulled out of the wall outlet11. Thus, a trouble may not occur such that the battery26has decreased without realizing it. Furthermore, the AC circuit30may have the adjusting element, i.e., the bidirectional thyristor Q13, and the DC circuit40may include the adjusting element, i.e., the second FET Q11, which are used for adjusting electric power supplied to the motor14. The microcomputer A1may open and/or close the contacts of the RL1-RL6and the RL7-RL12while the adjusting elements Q11and Q13are switched off. Accordingly, current may not flow when the contacts of the RL1-RL12are opened and/or closed. Thus, the contacts of the relays RL1-RL12may be reliably protected.

Furthermore, the first protection circuit51to the sixth protection circuit56(interlock circuits) may be provided such that the contacts of the RL1-RL6in the DC circuit40may not be closed while the contacts of the RL7-RL12in the AC circuit30are closed, as shown inFIG. 6. Because of this construction, even if the microcomputer A1malfunctions, a failure such that current flows simultaneously both in the AC circuit30and the DC circuit40may not occur. Furthermore, the first relay switch RL7and the sixth relay switch RL12in the AC circuit, the first relay switch RL1and the sixth relay switch RL6in the DC circuit40, and the first protection circuit Si and the sixth protection circuit56(interlock circuits), respectively, may be mounted on the second electrical circuit board K2. Furthermore, the second relay switch RL8to the fifth relay switch RL11in the AC circuit30, the second relay switch RL2to the fifth relay switch RL5in the DC circuit40, and the second protection circuit52to the fifth protection circuit55(interlock circuits), respectively, may be mounted on the third electrical circuit board K3. Because of this construction, wirings of the first protection circuit51to the sixth protection circuit56(interlock circuits) may not be crossed between the electrical circuit boards. Accordingly, disconnection of the wirings of the interlock circuits comprising the first protection circuit51to the sixth protection circuit56etc. can be prevented. Thus, reliability of the first protection circuit51and the sixth protection circuit56can be improved.

The present invention is not limited to the embodiments discussed above and may be further modified without departing from the scope and spirit of the present teachings. For example, in the embodiments discussed above, three relay switches (RL7-RL9) may be provided in the positive line31and three relay switches (RL10-RL12) in the negative line32of the AC circuit30. Furthermore, three relay switches (RL1-RL3) may be provided in the positive line41and three relay switches (RL4-RL6) in the negative line43of the DC circuit40. However, by use of a large-sized relay switch in which intervals of the relay terminal are large when the contacts are opened, the number of relay switches provided in the positive lines31and41and the negative lines32and43may be decreased. Furthermore, in the embodiments discussed above, the second protection circuit52to the fifth protection circuit55may be mounted on the third electrical circuit board K3. However, these protection circuits52-55may be mounted on the second electrical circuit board K2. Furthermore, in the embodiments discussed above, the dust collector10may be exemplified as an electronic power equipment. However, other than the dust collector10, the present teaching may be applied to other electronic power equipment, such as an electronic lawn mower, an electronic high pressure washer, an electronic circular saw, an electronic reciprocating saw, an electronic cutter, an electronic chain saw, or an electronic planar, etc.