Battery charging device

Abstract

A battery charging device according to the present invention is provided with: a rectifying unit for outputting, as charging power for a battery, a direct current obtained by rectifying a three-phase alternating current by turning on switching elements connected to respective output signal lines for the three-phase alternating current output by a generator according to the rotation of a rotor; a power supply holding switch capable of holding the control power from the switching element of the battery in a state in which the control power can be supplied when the main switch is in an off state in which the supply of the control power to the power supply line is stopped; and a control unit that controls the conduction of the switching elements, holds the power supply holding switch in a state in which control power can be supplied to the switching elements when the main switch is in an off state, and controls the negative electrode-side switching element connected to the negative electrode terminal of the battery in a conduction state when the rotor rotates.

Description

Technical Field

[0001] The present invention relates to a battery charging device.

[0002] This application claims priority based on Japanese Patent Application No. 2022-120340 filed in Japan on July 28, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] In recent years, battery charging devices for vehicles such as motorcycles are known (for example, see Patent Document 1). In such conventional battery charging devices, a switching element such as a MOSFET (metal oxide semiconductor) is used to rectify the three-phase AC power output from a generator using a full-bridge structure.

[0004] [Prior art literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2012-120293

[0006] However, in the conventional battery charging device, for example, when the main switch is turned off during the rotation of the generator (while the vehicle is running), the supply of power source power (power for controlling the switching element) stops, and the control of the switching element stops, and the alternating current generated by the generator is sometimes rectified by the parasitic diode of the switching element. In this case, since the rectification is performed by the parasitic diode with a high resistance, the switching element heats up, the device becomes abnormal, and there is a possibility that the battery is overcharged.

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a battery charging device capable of suppressing heat generated when supply of power from a power source is stopped during rotation of a generator, and suppressing overcharging of a battery. Summary of the invention

[0008] A battery charging device according to one embodiment of the present invention includes: a rectifier unit, which outputs direct current power obtained by rectifying the three-phase alternating current as charging power for a battery by turning on a switch element connected to each output signal line of the three-phase alternating current output by a generator according to the rotation of a rotor; a power supply holding switch, which can keep the control power of the switch element from the battery in a supplyable state when a main switch that supplies the control power of the switch element from the battery to the power supply line is in an off state that stops supplying the control power to the power supply line; and a control unit, which controls the conduction of the switch element, keeps the power supply holding switch in a state in which the control power of the switch element can be supplied when the main switch is in the off state, and controls the switch element on the negative pole side connected to the negative pole terminal of the battery to be in a conducting state when the rotor rotates.

[0009] In addition, one embodiment of the present invention is that in the above-mentioned battery charging device, the switching element is a MOS transistor, and the rectifier unit has a rectifier bridge, which has, for each of the output signal lines,: a MOS transistor on the positive side, connected between the power line on the positive side connected to the positive terminal of the battery and the output signal line; and a MOS transistor on the negative side, connected between the power line on the negative side connected to the negative terminal of the battery and the output signal line, and the control unit controls the MOS transistor on the negative side of the rectifier bridge to be in an on state when the rotor rotates.

[0010] In addition, one embodiment of the present invention is characterized in that, in the above-mentioned battery charging device, the control unit causes the MOS transistor on the positive electrode side and the MOS transistor on the negative electrode side to be in a non-conducting state within a prescribed period, and alternately and repeatedly performs a rotation detection process for detecting whether the rotor is rotating and a conduction process for controlling the MOS transistor on the negative electrode side to be in a conducting state.

[0011] In one aspect of the present invention, in the battery charging device, the control unit detects whether the rotor is rotating based on a voltage output from the generator to the output signal line.

[0012] In addition, one embodiment of the present invention, in the above-mentioned battery charging device, includes: a rotation detection unit, which detects whether the rotor is rotating based on the DC voltage after the three-phase AC power is rectified by a diode, and the control unit detects whether the rotor is rotating based on the detection result of the rotation detection unit.

[0013] In addition, one aspect of the present invention may be that, in the battery charging device described above, when the control unit detects that the rotor has stopped, the control unit switches the power supply holding switch to a state in which supply of control power to the switching element is stopped.

[0014] Effects of the Invention

[0015] According to the present invention, the battery charging device secures the control power of the switch element of the rectifier section by the power supply holding switch when the main switch is in the off state, and when the rotor of the generator is rotating, the switch element on the negative electrode side is turned on, and the output signal line of the generator is controlled to be the same potential as the negative electrode terminal of the battery. As a result, the battery charging device can suppress the rectification of the parasitic diode of the switch element, thereby suppressing the heat generated when the supply of power source power is stopped during the rotation of the generator, and also suppressing overcharging (overvoltage) of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1This is a block diagram of an example of a battery charging device according to this embodiment.

[0017] Figure 2 This is a flowchart showing an example of the operation of the battery charging device according to this embodiment.

[0018] Figure 3 This is a timing chart showing an example of the operation of the battery charging device according to the embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, a battery charging device according to an embodiment of the present invention will be described with reference to the drawings.

[0020] Figure 1 This is a block diagram of an example of the battery charging device 1 according to the present embodiment.

[0021] like Figure 1 As shown, the battery charging device 1 includes: a power holding switch 11, a power disconnection detection unit 14, an internal power generation unit 15, a sensor input buffer 16, a rotation detection unit 19, a rectifier unit 20, a control unit 30, a FET driver unit 31, diodes (12, 13, 18, 32~34), and a resistor 17.

[0022] The battery charging device 1 is also connected to the ACG 2 , the battery 3 , the load section 4 , the main switch 5 , the fuse 6 , and the rotation position sensor 7 .

[0023] ACG (alternating current generator) 2 is a generator that generates an AC signal. ACG 2 outputs a three-phase (U-phase, V-phase, W-phase) AC signal according to the rotation of a rotor (not shown). Here, the rotor is, for example, a crankshaft connected to the rotating shaft of an internal combustion engine (engine) of a motorcycle.

[0024] The battery 3 is, for example, a lead-acid battery, and the + (positive) electrode (positive terminal) is connected to the power supply line L1 on the positive side via the fuse 6, and the - (negative) electrode (negative terminal) is connected to the ground terminal (ground line L2). The battery 3 can be charged with direct current obtained by rectifying the three-phase (U phase, V phase, W phase) AC signal generated by the ACG2 through the rectifying unit 20.

[0025] The load unit 4 is, for example, a motorcycle electrical component, such as an ECU (Engine Control Unit), a fuel pump, an injection device, various sensors, etc. The load 4 operates with power generated by the ACG 2 or power output from the battery 3 supplied by the main switch 5 and consumes power.

[0026] The main switch 5 is a switch disposed between the power supply line L1 and the node N5 (power supply line), and is used, for example, to start a motorcycle. The main switch 5 supplies control power of the switching elements (21 to 26) of the battery 3 to the power supply line (node ​​N5 and node N7).

[0027] The fuse 6 is disposed between the power line L1 and the positive electrode of the battery 3 to prevent an overcurrent of a charging current to the battery 3 or an output current of the battery 3 .

[0028] The rotation position sensor 7 is a sensor for detecting the rotation position of the ACG 2 . A detection signal of the rotation position sensor 7 is input to the sensor input buffer 16 via the load unit 4 and the diode 18 .

[0029] The rectifier 20 outputs the DC power rectified from the three-phase AC power as charging power for the battery 3 by turning on the switching elements (21-26) connected to the output signal lines of the three-phase AC power outputted from the ACG2. The rectifier 20 includes the switching elements (21-26) and the capacitor 27.

[0030] The switch elements (21-26) are elements for synchronously rectifying the three-phase AC signals output by ACG2, and are, for example, N-channel MOS (metal oxide semiconductor) transistors, FET (field effect transistors). In addition, the switch elements (21-26) have body diodes, and are connected between the power line L1 and the ground line L2 in a manner such that the body diodes are forward from the ground line L2 toward the power line L1.

[0031] The switching elements (21 to 23) are MOS transistors on the positive side connected between the power supply line L1 on the positive side connected to the positive terminal of the battery 3 and the output signal line (node ​​N1 to node N3) relative to each output signal line (node ​​N1 to node N3) of the three-phase AC signal.

[0032] The switch elements (24 to 26) are negative-side MOS transistors connected between a negative-side power supply line (ground line L2) connected to the negative terminal of the battery 3 and an output signal line (nodes N1 to N3).

[0033] The MOS transistors on the positive side (switching elements (21 to 23)) and the MOS transistors on the negative side (switching elements (24 to 26)) constitute a rectifier bridge. In other words, the rectifier unit 20 has a rectifier bridge having MOS transistors on the positive side (switching elements (21 to 23)) and MOS transistors on the negative side (switching elements (24 to 26)).

[0034] In the rectifier 20, the switch element 21 and the switch element 24 are connected in series via a node N1 between the power line L1 and the ground line L2, and the switch element 22 and the switch element 25 are connected in series via a node N2 between the power line L1 and the ground line L2. In addition, the switch element 23 and the switch element 25 are connected in series via a node N3 between the power line L1 and the ground line L2.

[0035] The capacitor 27 is disposed between the positive-side power supply line L1 and the ground line L2 , and flattens the DC voltage rectified by the rectifier bridge of the rectifier unit 20 .

[0036] The power supply holding switch 11 is a switch that can maintain a state in which the control power can be supplied to the switch elements (21 to 26) of the battery 3 when the main switch 5 is in an OFF state in which the control power is stopped from being supplied to the power supply line (node ​​N5 and node N7). The power supply holding switch 11 is controlled to be turned on by a control signal of the control unit 30 described later. When the power supply holding switch 11 is in an OFF state (non-conductive state), the control power is stopped from being supplied. In addition, when the power supply holding switch 11 is in a conductive state, the control power can be supplied.

[0037] The power-off detection unit 14 detects, based on the voltage at the node N5 , that the main switch 5 is turned off and the supply of control power to the node N5 is stopped, and outputs the detection result to the control unit 30 .

[0038] The diode 12 has an anode terminal connected to the node N5 and a cathode terminal connected to the node N7 , thereby preventing the control power supplied through the power supply holding switch 11 from flowing back to the node N5 .

[0039] The diode 12 has an anode terminal connected to the node N6 and a cathode terminal connected to the node N7 , and can prevent the control power supplied via the main switch 5 from flowing back to the node N6 .

[0040] The internal power supply generating unit 15 generates a control voltage for driving the switching elements (21 to 26) of the rectifying unit 20 and for operating the control unit 30, based on the output power of the battery 3 supplied to the node N7 or the power rectified by the rectifying unit 20. The control voltage generated by the internal power supply generating unit 15 is supplied to the control unit 30 and to the FET driver unit 31.

[0041] The sensor input buffer 16 receives the detection signal of the rotation position sensor 7 via the load unit 4 and the diode 18 and converts the detection signal into a voltage that can be received by the control unit 30. The sensor input buffer 16 supplies the control unit 30 with a signal indicating the rotation position of the ACG2.

[0042] The resistor 17 is a pull-up resistor disposed between the node N7 and the node N8.

[0043] The anode terminal of the diode 18 is connected to the node N8, and the cathode terminal is connected to the detection signal of the rotation position sensor 7 through the load 4. The diode 18 prevents the detection signal of the rotation position sensor 7 from flowing back to the node N8 through the load 4.

[0044] The rotation detection unit 19 detects whether the rotor is rotating based on the DC voltage (voltage of node N4) obtained by rectifying the three-phase AC power through the diodes (32 to 34). The rotation detection unit 19 determines that the rotor is rotating when, for example, the voltage of node N4 is greater than the output voltage of the battery 3. The rotation detection unit 19 provides a detection signal indicating whether the rotor is rotating to the control unit 30.

[0045] The diode 32 has an anode terminal connected to the node N1 and a cathode terminal connected to the node N4 , and outputs a DC voltage obtained by rectifying the U-phase AC signal by a system different from that of the rectifying unit 20 .

[0046] The diode 33 has an anode terminal connected to the node N2 and a cathode terminal connected to the node N4 , and outputs a DC voltage obtained by rectifying the V-phase AC signal by a system different from that of the rectifying unit 20 .

[0047] The diode 34 has an anode terminal connected to the node N3 and a cathode terminal connected to the node N4 , and outputs a DC voltage obtained by rectifying the W-phase AC signal by a system different from that of the rectifying unit 20 .

[0048] The FET driver section 31 converts the control signal output from the control section 30 into a drive signal for the switching elements (21 to 26). The FET driver section 31 generates a drive signal for the switching elements (21 to 26) based on the control voltage generated by the internal power generation section 15.

[0049] The control unit 30 is a processor including a CPU (Central Processing Unit), for example, and controls the battery charging device 1 in a unified manner. When the main switch 5 is in the on state, the control unit 30 controls the switching elements (21 to 26) based on the rotation position information detected by the rotation position sensor 7, so as to appropriately charge the battery 3 through synchronous rectification by the rectifying unit 20. The control unit 30 outputs a control signal for controlling the conduction of the switching elements (21 to 26) through the FET driver unit 31.

[0050] Furthermore, when the main switch 5 is in the OFF state, the control unit 30 keeps the power supply holding switch 11 in a state capable of supplying control power to the switch elements (21 to 26), and controls the switch element (24) on the negative side connected to the negative terminal of the battery 3 to be in the ON state when the rotor rotates. That is, when the main switch 5 is in the OFF state and the rotor rotates, the control unit 30 controls the MOS transistor (switching elements (24 to 26)) on the negative side of the rectifier bridge of the rectifier unit 20 to be in the ON state.

[0051] The control unit 30 detects that the main switch 5 is turned off using the power off detection unit 14. When the power off detection unit 14 detects that the main switch 5 is turned off, the control unit 30 controls the power holding switch 11 to be turned on.

[0052] In addition, the control unit 30 repeatedly and alternately executes, within a specified period, the following: a rotation detection process of placing the switching elements (21 to 23) on the positive pole side and the switching elements (24 to 26) on the negative pole side in an off state (non-conducting state) and detecting whether the rotor is rotating; and a conduction process of controlling the switching elements (24 to 26) on the negative pole side to be in a conducting state.

[0053] The control unit 30 detects whether the rotor is rotating based on the voltage outputted from the ACG2 to the output signal line (nodes N1, N2, and N3). Specifically, the control unit 30 detects whether the rotor is rotating based on the detection result of the rotation detector 19.

[0054] When the control unit 30 detects that the rotor has stopped, the control unit 30 switches the power supply holding switch 11 to a state where the control power supply to the switching elements (21 to 26) is stopped. That is, when the control unit 30 detects that the rotor has stopped rotating, the control unit 30 controls the power supply holding switch 11 to switch to an off state.

[0055] Next, the operation of the battery charging device 1 according to the present embodiment will be described with reference to the drawings.

[0056] Figure 2 This is a flowchart showing an example of the operation of the battery charging device 1 according to the present embodiment. Figure 2 The operation when the main switch 5 is switched from the on state (the supply state of the control power) to the off state will be described.

[0057] like Figure 2As shown, the battery charging device 1 first determines whether the disconnected state of the main switch 5 is detected (step S101). The control unit 30 of the battery charging device 1 determines whether the disconnected state of the main switch 5 is detected based on the output of the power disconnection detection unit 14. In addition, the power disconnection detection unit 14 detects that the main switch 5 is in the disconnected state when the voltage of the node N5 becomes less than the threshold voltage. When it is detected that the main switch 5 is in the disconnected state (step S102: Yes), the control unit 30 advances the processing to step S102. In addition, when the on state of the main switch 5 is detected (step S101: No), the control unit 30 returns the processing to step S101.

[0058] In step S102, the control unit 30 keeps the power supply holding switch 11 in a state where the control power can be supplied. In other words, the control unit 30 controls the power supply holding switch 11 to be in the on state. Thus, the power supply voltage of the power supply line L1 is supplied to the internal power supply generating unit 15 through the power supply holding switch 11 and the diode 13, thereby ensuring the operating power supply of the control unit 30 and the FET driver unit 31.

[0059] Then, the control unit 30 detects whether ACG2 is rotating based on the output voltage of ACG2 (step S103). The control unit 30 first controls the switching elements (21-23) on the positive side and the switching elements (24-26) on the negative side to be in an off state, and the rotation detection unit 19 detects whether ACG2 is rotating based on the voltage of the node N4 obtained by rectifying the three-phase AC signal using the diodes (32-34). The control unit 30 detects whether ACG2 is rotating based on the detection result of the rotation detection unit 19.

[0060] Then, the control unit 30 determines whether ACG2 (rotor) has rotated (step S104). If ACG2 (rotor) has rotated (step S105: Yes), the control unit 30 advances the process to step S105. If ACG2 (rotor) has not rotated (step S107: No), the control unit 30 advances the process to step S107.

[0061] In step S105, the control unit 30 turns on the negative electrode side switching elements (24 to 26). The control unit 30 outputs a control signal for turning on the negative electrode side switching elements (24 to 26) through the FET driver unit 31.

[0062] Next, the control unit 30 maintains the state for a predetermined period of time (step S106). In addition, during the predetermined period, since the switch elements (24 to 26) on the negative electrode side are controlled to be in the on state, a large current can flow, which corresponds to a cooling period in which the heat generation of the switch elements (24 to 26) on the negative electrode side is suppressed. After the processing in step S106, the control unit 30 returns the processing to step S103.

[0063] In addition, in step S107, the control unit 30 controls the power supply holding switch 11 to switch to the power supply stop state. That is, when the rotation of the ACG2 (rotor) is stopped, the control unit 30 controls the power supply holding switch 11 to switch to the off state. After the processing of step S107, the control unit 30 ends the processing.

[0064] Figure 3 This is a timing chart showing an example of the operation of the battery charging device 1 according to the present embodiment.

[0065] exist Figure 3 In the figure, the waveforms are, from top to bottom, the state of the main switch 5 (waveform W1), the output of the power off detection unit 14 (waveform W2), the state of the power hold switch 11 (waveform W3), the state of the switching elements (21 to 23) on the positive side (waveform W4), the state of the switching elements (24 to 26) on the negative side (waveform W5), and the output (waveform W6) of the rotation detection unit 19. In addition, the horizontal axis of each waveform represents time.

[0066] like Figure 3 As shown, when the main switch 5 changes from the on state to the off state at time T1 (see waveform W1), the output of the power off detection unit 14 changes from the power supply state to the power off state (see waveform W2). In addition, even if the output of the power off detection unit 14 is detected to be in the power off state, the control unit 30 maintains the on state of the power holding switch 11 (see waveform W3). As a result, the power supply voltage of the power line L1 is supplied to the internal power generation unit 15, and the operating power supply of the control unit 30 and the FET driver unit 31 is ensured.

[0067] In addition, Figure 3 In FIG. 1 , the period of the oblique lines between the positive-side switching elements (21 to 23) and the negative-side switching elements (24 to 26) indicates the phase control state. Figure 3 In the example, it is assumed that the initial states of the main switch 5 and the power supply holding switch 11 are both in the on state.

[0068] Next, at time T2, in order to detect the rotation of ACG2, the control unit 30 sets the switch elements (21-23) on the positive side and the switch elements (24-26) on the negative side to the off state (see waveforms W4 and W5). In addition, the control unit 30 obtains the output of the rotation detection unit 19, and because there is rotation, at time T3, while keeping the power supply holding switch 11 in the on state (see waveform W3), the switch elements 24-26 on the negative side are turned on (see waveforms W5 and W6).

[0069] The control unit 30 maintains this state for a predetermined period (period TR2). At time T4, in order to detect the rotation of ACG2, the control unit 30 again disconnects the switching elements (21 to 23) on the positive side and the switching elements (24 to 26) on the negative side (refer to waveform W4 and waveform W5).

[0070] Next, at time T5, the control unit 30 obtains the output of the rotation detection unit 19, and since there is rotation, the switch elements (24 to 26) on the negative side are turned on again (see waveforms W5 and W6). In addition, the processing at time T6 and time T7 is the same as the processing at time T4 and time T5.

[0071] At time T8, in order to detect the rotation of ACG2, the control unit 30 again turns the switch elements (21-23) on the positive side and the switch elements (24-26) on the negative side to the off state (see waveforms W4 and W5). Next, at time T9, the control unit 30 obtains the output of the rotation detection unit 19, and since there is no rotation, the power supply holding switch 11 is switched to the off state (see waveform W3).

[0072] exist Figure 3 Among them, the time period TR1 from time T2 to time T3, time T4 to time T5, time T6 to time T7, and time T8 to time T9 is the time period for the rotation detection process. In addition, the time period TR2 from time T3 to time T4, time T5 to time T6, and time T7 to time T8 is the time period for the conduction process, which is equivalent to the cooling period of the rectifier 20.

[0073] In addition, in the present embodiment, the period TR1 of the rotation detection process is set so as to be able to detect stable rotation without depending on the rotation speed of the ACG2 (rotator). The period TR2 (prescribed period) of the conduction process is set so as to appropriately suppress heat generation.

[0074] As described above, the battery charging device 1 of the present embodiment includes the rectifier 20, the power supply holding switch 11, and the control unit 30. The rectifier 20 outputs the direct current obtained by rectifying the three-phase alternating current as the charging power of the battery 3 by turning on the switch elements (21 to 26) connected to the output signal lines (nodes N1, N2, and N3) of the three-phase alternating current output by the ACG2 (generator) according to the rotation of the rotor. The power supply holding switch 11 keeps the control power of the switch elements 21 to 26 of the battery 3 in a state where the control power can be supplied to the power supply line (power supply line L1) when the main switch 5 that supplies the control power of the switch elements 21 to 26 of the battery 3 is in an OFF state to stop supplying the control power to the power supply line. The control unit 30 controls the conduction of the switch elements (21 to 26). In addition, when the main switch 5 is in the disconnected state, the control unit 30 maintains the power supply holding switch 11 in a state capable of supplying control power to the switching elements (21 to 26), and when the rotor rotates, controls the switching elements (24 to 26) on the negative side connected to the negative terminal (ground line L2) of the battery 3 to be in the on state.

[0075] In this way, when the main switch 5 is turned off, the battery charging device 1 of the present embodiment ensures the control power of the switch elements (21 to 26) of the rectifier 20 through the power supply holding switch 11, and when the rotor of the ACG2 rotates, the switch elements (24 to 26) on the negative side are turned on, and the output signal line of the ACG2 is controlled to have the same potential as the negative terminal (ground line L2) of the battery 3. In this way, the battery charging device 1 of the present embodiment can suppress the rectification of the switch elements (21 to 26) by the parasitic diode (body diode), thereby suppressing the heat generated when the supply of power supply is stopped during the rotation of the ACG2, and suppressing the overcharge (overvoltage) of the battery 3.

[0076] In addition, in the present embodiment, the switching elements (21 to 26) are MOS transistors. The rectifier 20 includes a rectifier bridge. The rectifier bridge has, with respect to respective output signal lines (node ​​N1, node N2, node N3), MOS transistors (switching elements (21 to 23)) on the positive side connected between the power line L1 on the positive side connected to the positive terminal of the battery 3 and the output signal line, and MOS transistors (switching elements (24 to 26)) on the negative side connected between the power line (ground line L2) on the negative side connected to the negative terminal of the battery 3 and the output signal line. When the rotor rotates, the control unit 30 controls the MOS transistors (switching elements (24 to 26)) on the negative side of the rectifier bridge to be in an on state.

[0077] As described above, the battery charging device 1 of the present embodiment can efficiently perform rectification by including a rectifier bridge, and can easily suppress heat generation by controlling the negative-side MOS transistors (switching elements 24 to 26 ) included in the rectifier bridge to be in an on state.

[0078] In addition, in the present embodiment, the control unit 30 keeps the MOS transistors on the positive side (switching elements 21 to 23) and the MOS transistors on the negative side (switching elements 24 to 26) in the off state (non-conducting state) within a specified period, and alternately and repeatedly performs a rotation detection process (processing during period TR1) for detecting whether the rotor is rotating, and a conduction process (processing during period TR2) for controlling the MOS transistors on the negative side (switching elements 24 to 26) to be in the on state.

[0079] In this way, the battery charging device 1 of this embodiment can accurately detect the rotation of the rotor by alternately and repeatedly performing the rotation detection process (processing during period TR1) and the conduction process (processing during period TR2), and can appropriately suppress the heat caused by the parasitic diodes (body diodes) of the switching elements 21 to 26.

[0080] Furthermore, in the present embodiment, the control unit 30 detects whether the rotor is rotating based on the voltage output to the ACG2 output signal line (the node N1 , the node N2 , and the node N3 ).

[0081] In this way, the battery charging device 1 of the present embodiment uses the voltage outputted from ACG2 to the output signal line (node ​​N1 , node N2 , node N3 ), and therefore can appropriately detect whether the rotor is rotating with a simple configuration.

[0082] The battery charger 1 of the present embodiment includes a rotation detector 19 that detects whether the rotor is rotating based on a DC voltage (voltage of a node N4) obtained by rectifying three-phase AC power through diodes (32 to 34). The control unit 30 detects whether the rotor is rotating based on the detection result of the rotation detector 19.

[0083] In this way, the battery charging device 1 of this embodiment detects whether the rotor is rotating based on the DC voltage (voltage of the node N4) obtained by rectifying the three-phase AC power by the diodes (32 to 34), so that the rotation of the rotor can be appropriately detected with a simple structure.

[0084] Furthermore, in the present embodiment, when the control unit 30 detects the stop of the rotor, it switches the power supply holding switch 11 to a state (eg, an OFF state) in which the supply of control power to the switching elements ( 21 to 26 ) is stopped.

[0085] In this way, the battery charging device 1 of this embodiment switches the power supply holding switch 11 to a state (e.g., an off state) in which the control power supply to the switching elements (21 to 26) is stopped, thereby reducing the power consumption of the device when it is stopped (in standby mode). In other words, the battery charging device 1 of this embodiment can reduce dark current.

[0086] In addition, the present invention is not limited to the above-mentioned embodiment, and can be modified within the scope not departing from the gist of the present invention.

[0087] For example, in the above-mentioned embodiment, the switch elements (21 to 26) are described as examples of n-channel MOS transistors, but the present invention is not limited to this, and other switches may be used as long as they have parasitic diodes (body diodes).

[0088] In the above-described embodiment, an example in which the ACG2 outputs a three-phase AC signal is described, but the present invention is not limited thereto, and an AC signal of two or less phases or an AC signal of four or more phases may be output.

[0089] Furthermore, in the above-described embodiment, an example is described in which the rectifying unit 20 includes a rectifying bridge and performs full-wave rectification on the AC signal, but the present invention is not limited thereto, and other rectifying methods may be used.

[0090] In addition, a computer system is provided inside the battery charging device 1. Furthermore, each process when the main switch 5 is turned off is stored in a computer-readable recording medium in the form of a program, and the computer reads out and executes the program to perform the above-mentioned process. The computer-readable storage medium refers to a magnetic disk, an optical magnetic disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc. In addition, the computer program can be distributed to a computer via a communication line, and the computer receiving the distribution executes the program.

[0091] In the above embodiment, part or all of the functions of the battery charger 1 may be implemented as an integrated circuit such as LSI (Large Scale Integration). Each of the above functions may be implemented as a separate processor or part or all of them may be integrated into a processor.

[0092] In addition, the method of realizing integrated circuit is not limited to LSI, and it can also be realized by using a dedicated circuit or a general-purpose processor. In addition, with the progress of semiconductor technology, when an integrated circuit technology that replaces LSI appears, an integrated circuit of this technology can be used.

[0093] Explanation of symbols

[0094] 1Battery charging device

[0095] 2ACG

[0096] 3 Batteries

[0097] 4 Load section

[0098] 5 Main switch

[0099] 6 Fuse

[0100] 7 Rotary position sensor

[0101] 11 Power hold switch

[0102] 12, 13, 18, 32, 33, 34 diodes

[0103] 14 Power off detection unit

[0104] 15 Internal power generation unit

[0105] 16 Sensor input buffer

[0106] 19 Rotation detection unit

[0107] 20 Rectification Unit

[0108] 21, 22, 23, 24, 25, 26 Switching elements

[0109] 27 Capacitor

[0110] 30 Control Department

[0111] 31 FET driver section.

Claims

1. A battery charging device, characterized in that: include: a rectifier that outputs a DC power rectified from the three-phase AC power as charging power for the battery by turning on a switching element connected to each output signal line of the three-phase AC power output by the generator in accordance with the rotation of the rotor; a power supply holding switch capable of keeping the control power of the switching element from the battery in a supplyable state when a main switch that supplies the control power of the switching element from the battery to the power supply line is in an off state that stops supplying the control power to the power supply line; as well as A control unit controls the conduction of the switching element, maintains the power supply holding switch in a state capable of supplying control power to the switching element when the main switch is in the disconnected state, and controls the switching element on the negative electrode side connected to the negative electrode terminal of the battery to be in the on state when the rotor rotates.

2. The battery charging device according to claim 1, characterized in that: in, The switching element is a MOS transistor, The rectifier unit includes a rectifier bridge, which has, for each of the output signal lines, a positive-side MOS transistor connected between a positive-side power line connected to the positive terminal of the battery and the output signal line; and a negative-side MOS transistor connected between a negative-side power line connected to the negative terminal of the battery and the output signal line. The control unit controls the negative-side MOS transistor included in the rectifier bridge to be in an on state when the rotor rotates.

3. The battery charging device according to claim 2, characterized in that: The control unit causes the MOS transistor on the positive side and the MOS transistor on the negative side to be in a non-conducting state within a specified period, and alternately and repeatedly performs a rotation detection process for detecting whether the rotor is rotating and a conduction process for controlling the MOS transistor on the negative side to be in a conducting state.

4. The battery charging device according to claim 1, characterized in that: The control unit detects whether the rotor is rotating based on a voltage outputted from the generator to the output signal line.

5. The battery charging device according to claim 4, characterized in that: include: a rotation detection unit for detecting whether the rotor is rotating based on a DC voltage obtained by rectifying the three-phase AC power by a diode, The control unit detects whether the rotor is rotating based on the detection result of the rotation detection unit.

6. The battery charging device according to any one of claims 1 to 5, characterized in that: When the control unit detects that the rotor has stopped, the control unit switches the power supply holding switch to a state in which supply of control power to the switching element is stopped.

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