JP2015130725A - Charge control device and emergency lighting equipment using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge control device capable of reducing an electric stress applied to a component constituting a charging circuit when a secondary battery short-circuits.SOLUTION: A charge control device 1 comprises a secondary battery RB1, a charging circuit 2, and a control unit 4. The charging circuit 2 charges the secondary battery RB1 by power supply from an external power supply (commercial power supply AC1). The control unit 4 controls charge and discharge of the secondary battery RB1. The control unit 4 includes a function to control the output current I1 output from the charging circuit 2 to the secondary battery RB1, and a function to detect a state of the secondary battery RB1 on the basis of the voltage between the terminals of the secondary battery RB1 developed by the output current I1. The state of the secondary battery RB1 includes at least the short-circuit of the secondary battery RB1 and coming off of the secondary battery RB1. When it detects the short-circuit of the secondary battery RB1, the control unit 4 controls a switching element so as to intermittently pass the output current I1.

Description

  The present invention generally relates to a charging control device, and more particularly to a charging control device including a charging circuit that charges a secondary battery by supplying power from an external power source, and an emergency lighting device using the same.

  2. Description of the Related Art Conventionally, an emergency lighting fixture that emits light from a light source unit in an emergency in which the supply of power from an external power source becomes abnormal is disclosed, for example, in Patent Document 1. The emergency lighting fixture described in Patent Literature 1 includes a storage battery control unit (charging circuit) that is electrically connected to a commercial power source that is an external power source inside the fixture body. Moreover, in this emergency lighting fixture, the storage battery control unit and the storage battery unit (secondary battery) inside the fixture body are electrically connected, and the storage battery control unit is always supplied with power from a commercial power source. The storage battery is charged. Furthermore, in this emergency lighting fixture, the storage battery control unit and the lighting control unit that lights the light source unit inside the fixture body are electrically connected.

  The storage battery control unit supplies the power of the storage battery unit to the lighting control unit via the power feeding path when detecting an emergency in which the supply of power from the commercial power supply becomes abnormal. The lighting control unit outputs electric power from the storage battery unit via the power feeding path, and controls lighting of the light source unit.

JP 2012-133940 A

  However, since the conventional example has a configuration in which the output current of the charging circuit is continuously supplied to the secondary battery, when the secondary battery is short-circuited, there is a possibility that excessive electrical stress is applied to the components constituting the charging circuit. For this reason, in the above-mentioned conventional example, it is necessary to select a part with a large rating in view of excessive electrical stress at the time of a short circuit of the secondary battery, which causes a problem that the circuit is enlarged and the manufacturing cost is increased. there were.

  The present invention has been made in view of the above points, and a charging control device capable of reducing electrical stress applied to components constituting a charging circuit when a secondary battery is short-circuited and emergency lighting using the same An object is to provide an apparatus.

  The charging control device of the present invention includes a secondary battery, a charging circuit that charges the secondary battery by supplying power from an external power source, and a control unit that controls charging and discharging of the secondary battery, and the control unit Has a function of controlling an output current output from the charging circuit to the secondary battery, and a function of detecting a state of the secondary battery based on a voltage between terminals of the secondary battery generated by the output current. And the state of the secondary battery includes at least a short circuit of the secondary battery and a battery detachment of the secondary battery, and the control unit detects the short circuit of the secondary battery and outputs the output Control is performed so that a current flows intermittently.

  In this charging control apparatus, it is preferable that the control unit performs control so as to reduce a current value of the output current when detecting a short circuit of the secondary battery.

  In this charging control apparatus, it is preferable that the control unit does not detect the state of the secondary battery for a predetermined period from the rise of the output current.

  In this charging control device, the control unit detects the state of the secondary battery when the secondary battery is mounted, and continues to flow the output current when detecting that the secondary battery is normal. When the short circuit of the secondary battery is detected, the output current is preferably controlled to flow intermittently.

  In this charging control apparatus, it is preferable that the control unit performs control so that the output current continues to flow when detecting a battery detachment of the secondary battery when the secondary battery is short-circuited.

  An emergency lighting device according to the present invention includes any one of the above-described charging control devices, a light source, and a lighting circuit that turns on the light source by supplying power from the secondary battery.

  Since the control unit controls the output current of the charging circuit to flow intermittently when the control unit detects a short circuit of the secondary battery, compared with the case where the output current continues to flow, It is possible to reduce electrical stress applied to components constituting the charging circuit.

It is the schematic which shows the charge control apparatus and emergency lighting apparatus which concern on embodiment of this invention. 2A and 2B are explanatory diagrams of operations in the charge control device according to the embodiment of the present invention. It is the schematic which shows the other structure of the charging control apparatus which concerns on embodiment of this invention, and an emergency illuminating device. 4A and 4B are explanatory diagrams of operations in the charge control device shown in FIG. FIG. 5A and FIG. 5B are explanatory diagrams of the operation when the rising of the detection voltage is invalidated in the charge control device according to the embodiment of the present invention. 6A and 6B are explanatory diagrams of an output current switching operation when the secondary battery is in a normal state when attached in the charge control device according to the embodiment of the present invention. 7A and 7B are explanatory diagrams of the output current switching operation when the secondary battery is in an abnormal state when attached in the charge control device according to the embodiment of the present invention. 8A and 8B are explanatory diagrams of an output current switching operation when the secondary battery is disconnected in an abnormal state in the charge control device according to the embodiment of the present invention.

  As shown in FIG. 1, the charging control device 1 according to the embodiment of the present invention includes a secondary battery RB <b> 1, a charging circuit 2, and a control unit 4. The charging circuit 2 charges the secondary battery RB1 by supplying power from an external power supply (commercial power supply AC1). Control unit 4 controls charging / discharging of secondary battery RB1. Further, the control unit 4 controls the state of the secondary battery RB1 based on the function of controlling the output current I1 output from the charging circuit 2 to the secondary battery RB1 and the voltage across the terminals of the secondary battery RB1 generated by the output current I1. It has a function to detect. The state of the secondary battery RB1 includes at least a short circuit of the secondary battery RB1 and a battery detachment of the secondary battery RB1. Then, when detecting a short circuit of the secondary battery RB1, the control unit 4 controls the output current I1 to flow intermittently.

  Further, as shown in FIG. 1, the emergency lighting device 100 according to the embodiment of the present invention is a lighting circuit 3 that lights the light source LS <b> 1 by supplying power from the charging control device 1, the light source LS <b> 1, and the secondary battery RB <b> 1. With.

  Hereinafter, the charge control device 1 and the emergency lighting device 100 of the present embodiment will be described in detail. As shown in FIG. 1, the charge control device 1 of the present embodiment includes a secondary battery RB1, a charging circuit 2, and a control unit 4. The emergency lighting device 100 according to the present embodiment includes the charging control device 1, the light source LS <b> 1, and the lighting circuit 3.

  The secondary battery RB1 is composed of, for example, a lithium ion battery or a nickel metal hydride battery. In the charge control device 1 of the present embodiment, the secondary battery RB1 is an assembled battery composed of a plurality of cells, but may be composed of a single cell.

  The charging circuit 2 is configured to charge the secondary battery RB1 by supplying power from a commercial power supply AC1 that is an external power supply. The charging circuit 2 includes an AC / DC converter 20, a smoothing capacitor C1, a Zener diode ZD1, resistors R1 to R4, a diode D1, and switching elements Q1 and Q2. The AC / DC converter 20 converts AC power supplied from the commercial power supply AC1 into DC power and outputs it. In the charging control device 1 of the present embodiment, the AC / DC converter 20 is configured by a flyback converter. The AC / DC converter 20 may be configured with a conventionally known circuit, and thus a detailed description thereof is omitted here.

  A smoothing capacitor C <b> 1 is connected to the output end of the AC / DC converter 20. In addition, a series circuit of a Zener diode ZD1, a resistor R2, and a switching element Q2 is connected in parallel to the smoothing capacitor C1. The switching element Q1 is a PNP transistor. The cathode of the Zener diode ZD1 is connected to the emitter of the switching element Q1 via the resistor R1. The collector of the switching element Q1 is connected to the anode of the secondary battery RB1 through a backflow prevention diode D1. Further, the base of the switching element Q1 is connected to a connection point between the anode of the Zener diode ZD1 and the resistor R2.

  The switching element Q2 is an NPN transistor. The anode of the Zener diode ZD1 and the base of the switching element Q1 are connected to the collector of the switching element Q2 via the resistor R2. The emitter of the switching element Q2 is connected to the negative electrode of the secondary battery RB1. Further, the base of the switching element Q2 is connected to a current control unit 42 described later. A series circuit of resistors R3 and R4 is connected in parallel between terminals to which the respective electrodes of the secondary battery RB1 are connected.

  Hereinafter, the operation of the charging circuit 2 will be described. In the following description, it is assumed that the switching element Q2 is on. If the switching element Q2 is on, the base voltage of the switching element Q1 is a voltage obtained by dividing the voltage across the smoothing capacitor C1 by the Zener diode ZD1 and the resistor R2. Since the base current of the switching element Q1 flows through the resistor R2, the switching element Q1 is turned on. Here, since the voltage across the Zener diode ZD1 becomes a constant voltage, a constant current defined by the resistor R1 flows through the secondary battery RB1 as the output current I1. For this reason, the secondary battery RB1 is charged by the output current I1.

  The lighting circuit 3 is composed of, for example, a DC / DC converter or a current limiting resistor. A secondary battery RB1 is connected to the input terminal of the lighting circuit 3 via a normally open switch SW1. Therefore, when the switch SW1 is on, DC power is supplied from the secondary battery RB1 to the lighting circuit 3, and when the switch SW1 is off, the supply of DC power from the secondary battery RB1 to the lighting circuit 3 is stopped. . That is, the switch SW1 opens and closes an electric circuit between the secondary battery RB1 and the lighting circuit 3.

  A light source LS <b> 1 is connected to the output end of the lighting circuit 3. The light source LS1 is configured by connecting solid light emitting elements such as light emitting diodes in series, parallel, or series-parallel. The light source LS1 is lit by DC power supplied from the lighting circuit 3. That is, the lighting circuit 3 is configured to light the light source LS1 by supplying power from the secondary battery RB1. In addition, since the lighting circuit 3 may be comprised with a conventionally well-known circuit, detailed description is abbreviate | omitted here.

  The control unit 4 includes a charge / discharge switching unit 40 that controls charging / discharging of the secondary battery RB1, a state detection unit 41 that detects the state of the secondary battery RB1, and a current control unit 42 that controls the output current I1. . In other words, the controller 4 controls the charging / discharging of the secondary battery RB1, the function of controlling the output current I1 output from the charging circuit 2 to the secondary battery RB1, and the secondary generated by the output current I1. A function of detecting the state of the secondary battery RB1 based on the voltage across the terminals of the battery RB1. In the charge control device 1 of the present embodiment, the control unit 4 is configured by a microcomputer, and a predetermined program is executed by the microcomputer so that the functions of the charge / discharge switching unit 40, the state detection unit 41, and the current control unit 42 are performed. Realized. Of course, the charge / discharge switching unit 40, the state detection unit 41, and the current control unit 42 may each be configured by a single piece of hardware.

  The charge / discharge switching unit 40 detects the presence or absence of a power failure of the commercial power supply AC1 by monitoring the power supply voltage of the commercial power supply AC1. In the charge control device 1 of the present embodiment, the charge / discharge switching unit 40 monitors the power supply voltage of the commercial power supply AC1 by monitoring the output voltage of the smoothing capacitor C1 of the charging circuit 2. Then, when the output voltage of the smoothing capacitor C1 falls below a predetermined threshold, the charge / discharge switching unit 40 detects that the commercial power supply AC1 has failed. Since the configuration for monitoring the power supply voltage of the commercial power supply AC1 is conventionally known, detailed description thereof is omitted here.

  Charging / discharging switching unit 40 controls charging / discharging of secondary battery RB1 according to the presence or absence of a power failure of commercial power supply AC1. That is, when the charge / discharge switching unit 40 detects that the commercial power supply AC1 has failed, it gives a control signal to the switch SW1 to switch on the switch SW1. Then, the secondary battery RB1 is discharged and DC power is supplied to the lighting circuit 3, so that the light source LS1 is lit. On the other hand, when the commercial power supply AC1 is normal (that is, when the output voltage of the smoothing capacitor C1 exceeds a predetermined threshold), the charge / discharge switching unit 40 does not give a control signal to the switch SW1. For this reason, the normally open type switch SW1 maintains the off state. In this case, since the electric circuit between the secondary battery RB1 and the lighting circuit 3 is opened, the secondary battery RB1 is charged by the charging circuit 2.

  The state detection unit 41 monitors a voltage obtained by dividing the voltage between the terminals of the secondary battery RB1 by the resistors R3 and R4. Hereinafter, this voltage is referred to as “detection voltage”. As shown in FIG. 4A, the state detection unit 41 determines that the secondary battery RB1 is in the “normal” state if the detection voltage is between the first threshold voltage Vth1 and the second threshold voltage Vth2 (> Vth1). Detect. Further, when the detection voltage falls below the first threshold voltage Vth1, the state detection unit 41 detects that the secondary battery RB1 is in an “abnormal” state in which the secondary battery RB1 is short-circuited. This is because when the secondary battery RB1 is short-circuited, the impedance between the terminals to which the secondary battery RB1 is connected decreases, and the detection voltage decreases. Note that the short circuit of the secondary battery RB1 means that if the secondary battery RB1 is a single battery, the single battery is short-circuited. If the secondary battery RB1 is an assembled battery composed of a plurality of cells, It means that a cell is short-circuited or a part of cells is short-circuited. Further, when the detection voltage exceeds the second threshold voltage Vth2, the state detection unit 41 detects that the secondary battery RB1 is in the “battery removal” state. This is because when the secondary battery RB1 is detached, the terminals to which the electrodes of the secondary battery RB1 are connected are opened, the impedance increases, and the detection voltage rises.

  The “battery removed” state means a state where the secondary battery RB1 is electrically disconnected from the charging circuit 2. Here, since the secondary battery RB1 is a consumable item, it needs to be replaced when its life is exhausted or deteriorated. For this reason, in the charge control device 1 of the present embodiment, it is necessary to detect whether or not the secondary battery RB1 is detached, that is, a “battery detached” state. For example, when the secondary battery RB1 is removed by a human hand or the secondary battery RB1 is detached due to vibration, the state is changed to the “battery removed” state.

  The current control unit 42 gives a drive signal to the switching element Q2 according to the state of the secondary battery RB1 detected by the state detection unit 41, thereby switching the switching element Q2 on / off and controlling the output current I1. If the drive signal is at a high level, the switching element Q2 is turned on, and if the drive signal is at a low level, the switching element Q2 is turned off. If the switching element Q2 is on, the base current of the switching element Q1 flows, so that the switching element Q1 is turned on and the output current I1 flows. On the other hand, if the switching element Q2 is off, the collector current of the switching element Q2 does not flow, so the base current of the switching element Q1 does not flow, the switching element Q1 turns off, and the output current I1 does not flow.

  The current control unit 42 performs control so that the switching element Q2 is maintained in the ON state while the state detection unit 41 detects that the secondary battery RB1 is in a state other than the “abnormal” state. That is, when the secondary battery RB1 is not short-circuited, the output current I1 continues to flow.

  Here, the problem of the configuration in which the output current I1 continues to flow through the secondary battery RB1 as in the emergency lighting apparatus described in Patent Document 1 will be described. The configuration in which the output current I1 continues to flow corresponds to the configuration in which the switching element Q2 is kept on in the circuit of FIG. When the switching element Q2 is kept on, the output current I1 continues to flow to the secondary battery RB1. In this state, when the secondary battery RB1 is short-circuited, the power consumption in the switching element Q1 increases.

  For example, it is assumed that the terminal voltage of the secondary battery RB1 is 3.0V, the output current I1 is 50 mA, and the collector-emitter voltage of the switching element Q1 is 1.2V. In this case, the power consumption of the switching element Q1 during charging of the secondary battery RB1 is 0.06 W (= 1.2 V × 50 mA). On the other hand, the power consumption of the switching element Q1 when the secondary battery RB1 is short-circuited is 0.21 W (= (1.2 V + 3.0 V) × 50 mA) because the voltage across the terminals of the secondary battery RB1 is added. That is, the power consumption of the switching element Q1 when the secondary battery RB1 is short-circuited increases to about 3.5 times the power consumption during charging.

  Thus, in the configuration in which the output current I1 continues to flow through the secondary battery RB1, the power consumption of the switching element Q1 increases when the secondary battery RB1 is short-circuited. In other words, there is a possibility that excessive electrical stress is applied to the switching element Q1 which is a component constituting the charging circuit 2. For this reason, it is necessary to select the switching element Q1 having a large rated power in view of excessive electrical stress when the secondary battery RB1 is short-circuited, which causes a problem that the circuit is increased in size and the manufacturing cost is increased. It was.

  In order to solve the above problem, a configuration in which the output current I1 is stopped from flowing when the secondary battery RB1 is short-circuited can be considered. However, in this configuration, if the secondary battery RB1 is disconnected when the secondary battery RB1 is short-circuited, the output current I1 does not flow, and thus a new problem that the battery detachment of the secondary battery RB1 cannot be detected occurs.

  Therefore, in the charging control apparatus 1 of the present embodiment, as shown in FIG. 2, when the short circuit of the secondary battery RB1 is detected, the control unit 4 controls the output current I1 to flow intermittently. In other words, when the secondary battery RB1 is in the “abnormal” state, the current control unit 42 controls the switching element Q2 so that the output current I1 flows intermittently. Specifically, when the state detection unit 41 detects that the secondary battery RB1 is in the “abnormal” state, the current control unit 42 gives a 2 Hz pulse as a drive signal to the switching element Q2. This pulse has a pulse width of 50 ms, a pulse period of 500 ms, and a duty ratio of 0.1. Since the switching element Q2 is alternately turned on / off by this pulse, the output current I1 flows intermittently to the secondary battery RB1 (see FIG. 2). For this reason, since the effective value of the output current I1 that flows when the secondary battery RB1 is short-circuited is smaller than when the output current I1 is kept flowing, the power consumption of the switching element Q1 when the secondary battery RB1 is short-circuited is reduced. can do.

  Of course, the frequency and pulse width of the drive signal may be appropriately changed according to the design. Then, by appropriately changing the frequency and pulse width of the drive signal, the power consumption of the switching element Q1 when the secondary battery RB1 is short-circuited is reduced to the power consumption of the switching element Q1 when the secondary battery RB1 is charged. Is also possible.

  As described above, in the charge control device 1 of the present embodiment, the control unit 4 controls the output current I1 of the charging circuit 2 to flow intermittently when detecting a short circuit of the secondary battery RB1. For this reason, in the charge control device 1 of the present embodiment, compared with the case where the output current I1 is continuously supplied, the electrical stress (the switching element Q1 of the switching element Q1) applied to the components constituting the charging circuit 2 when the secondary battery RB1 is short-circuited Power consumption) can be reduced. Therefore, in the charging control device 1 of the present embodiment, it is not necessary to select a component (switching element Q1) having a large rating (rated power), so that the circuit is not increased in size and the manufacturing cost is not increased.

  Moreover, in the charge control apparatus 1 of this embodiment, since the output current I1 flows during the ON period of the switching element Q2, the state detection unit 41 can monitor the detection voltage during the period. That is, in the charge control device 1 of the present embodiment, since the output current I1 flows intermittently even when the secondary battery RB1 is short-circuited, it is possible to detect the battery detachment of the secondary battery RB1.

  In the charging control device 1 of the present embodiment, it is desirable that the control unit 4 performs control so as to decrease the current value of the output current I1 when detecting a short circuit of the secondary battery RB1. Hereinafter, a configuration for realizing this control will be described with reference to the drawings. In this configuration, as shown in FIG. 3, resistors R5 and R6 and a switching element Q3 are provided instead of the resistor R1. In this configuration, the control unit 4 is provided with a current switching unit 43 that gives a switching signal to the switching element Q3. The current switching unit 43 realizes its function by executing a predetermined program with a microcomputer. Of course, the current switching unit 43 may be configured by a single piece of hardware. The resistor R5 and the resistor R6 are connected in parallel. The switching element Q3 has a collector connected to the resistor R6, an emitter connected to the collector of the switching element Q1, and a base connected to the current switching unit 43.

  The current switching unit 43 switches the switching element Q3 on / off by giving a switching signal to the switching element Q3 according to the state of the secondary battery RB1 detected by the state detection unit 41, and sets the current value of the output current I1. Control. If the switching signal is at a high level, the switching element Q3 is switched on, and if the switching signal is at a low level, the switching element Q3 is switched off. When the switching element Q3 is on, the output current I1 is defined as the first current value CC1 by the combined resistance of the resistor R5 and the resistor R6. When the switching element Q3 is off, the output current I1 is defined as the second current value CC2 (<CC1) by the resistor R5 having a resistance value larger than the combined resistance.

  As shown in FIGS. 4A and 4B, the current switching unit 43 keeps the switching element Q3 on while the state detection unit 41 detects that the secondary battery RB1 is in the “normal” state. To control. For this reason, while the secondary battery RB1 is in the “normal” state, the output current I1 of the first current value CC1 flows. On the other hand, when the state detecting unit 41 detects that the secondary battery RB1 is in the “abnormal” state, the current switching unit 43 switches the switching element Q3 to OFF. For this reason, while the secondary battery RB1 is in the “abnormal” state, the output current I1 of the second current value CC2 flows.

  In this configuration, since the output current I1 that flows when the secondary battery RB1 is short-circuited can be reduced, the power consumption in the switching element Q1 can be further reduced.

  Even when the secondary battery RB1 is in the “normal” state, the output current I1 of the first current value CC1 is allowed to flow until a predetermined time elapses after the charging of the secondary battery RB1 is started, and the predetermined time elapses. After that, the output current I1 having the second current value CC2 may be supplied. In other words, the current switching unit 43 keeps the switching element Q3 on until a predetermined time elapses after the state detection unit 41 detects that the secondary battery RB1 is in the “normal” state. Control. Then, the current switching unit 43 switches the switching element Q3 off when a predetermined time has elapsed. In this configuration, the power consumption of the switching element Q1 can be further reduced by reducing the output current I1 that flows when the secondary battery RB1 is sufficiently charged.

  By the way, when the secondary battery RB1 is short-circuited, the voltage between the terminals of the secondary battery RB1 gradually increases in a predetermined period after the output current I1 starts flowing, and then becomes a constant voltage. Therefore, as shown in FIG. 5B, the detection voltage also gradually increases in a predetermined period after the switching element Q2 is turned on, and then becomes a constant voltage. For this reason, if the state of the secondary battery RB1 is detected during the rising period of the detection voltage, the state of the secondary battery RB1 may not be accurately detected.

  Therefore, in the charge control device 1 of the present embodiment, it is desirable that the control unit 4 does not detect the state of the secondary battery RB1 for a predetermined period from the rise of the output current I1. Specifically, as shown in FIG. 5A, the detection by the state detection unit 41 is invalidated for a predetermined period from the time when the current control unit 42 gives the drive signal to the switching element Q2, and when the predetermined period elapses, The detection by the state detection unit 41 is validated. For example, it is assumed that the predetermined period is 10 ms and the pulse width of the drive signal is 50 ms. In this case, the state detection unit 41 does not detect the state of the secondary battery RB1 for 10 ms from the time when the current control unit 42 gives the drive signal to the switching element Q2. Then, after 10 ms elapses, the state detection unit 41 acquires a detection voltage every 10 ms during the remaining 40 ms, and detects the state of the secondary battery RB1 from a total of four data. In this configuration, since the state of the secondary battery RB1 is detected by the state detection unit 41 after the detection voltage is stabilized, the accuracy of detecting the state of the secondary battery RB1 can be increased.

  In the charge control device 1 of the present embodiment, it is desirable that the control unit 4 detects the state of the secondary battery RB1 when the secondary battery RB1 is attached. Then, when the control unit 4 detects that the secondary battery RB1 is normal, it continues to flow the output current I1, and when it detects a short circuit of the secondary battery RB1, it controls the output current I1 to flow intermittently. Is desirable. That is, when the secondary battery RB1 shifts from the “battery removal” state to the “normal” state, the control unit 4 performs control so that the output current I1 continues to flow. Specifically, as shown in FIGS. 6A and 6B, when the detected voltage changes from a voltage exceeding the second threshold voltage Vth2 to a voltage between the first threshold voltage Vth1 and the second threshold voltage Vth2, the current control unit 42 controls the switching element Q2 to maintain the ON state.

  On the other hand, when the secondary battery RB1 shifts from the “battery removed” state to the “abnormal” state, the control unit 4 controls the output current I1 to flow intermittently. Specifically, as shown in FIGS. 7A and 7B, when the detected voltage changes from a voltage higher than the second threshold voltage Vth2 to a voltage lower than the first threshold voltage Vth1, the current control unit 42 turns on the switching element Q2. Switch between / off alternately.

  Further, in the charge control device 1 of the present embodiment, it is desirable that the control unit 4 performs control so that the output current I1 continues to flow when the battery detachment of the secondary battery RB1 is detected when the secondary battery RB1 is short-circuited. That is, when the secondary battery RB1 shifts from the “abnormal” state to the “battery disconnected” state, the control unit 4 performs control so that the output current I1 continues to flow. Specifically, as shown in FIGS. 8A and 8B, when the detected voltage changes from a voltage lower than the first threshold voltage Vth1 to a voltage higher than the second threshold voltage Vth2, the current control unit 42 turns on the switching element Q2. Control to maintain state. In this configuration, since the output current I1 continues to flow in a state where the secondary battery RB1 is detached, the state of the secondary battery RB1 can always be monitored.

DESCRIPTION OF SYMBOLS 1 Charge control apparatus 2 Charging circuit 3 Lighting circuit 4 Control part 41 State detection part 42 Current control part 100 Emergency lighting device LS1 Light source RB1 Secondary battery

Claims (6)

A secondary battery, a charging circuit that charges the secondary battery by supplying power from an external power source, and a control unit that controls charging and discharging of the secondary battery,
The control unit detects a state of the secondary battery based on a function of controlling an output current output from the charging circuit to the secondary battery and a voltage between terminals of the secondary battery generated by the output current. With functions,
The state of the secondary battery includes at least a short circuit of the secondary battery and a battery detachment of the secondary battery,
When the control unit detects a short circuit of the secondary battery, the control unit controls the output current to flow intermittently.   The charging control device according to claim 1, wherein the control unit performs control so as to reduce a current value of the output current when detecting a short circuit of the secondary battery.   3. The charge control device according to claim 1, wherein the control unit does not detect the state of the secondary battery for a predetermined period from a rise of the output current.   The control unit detects the state of the secondary battery when the secondary battery is mounted, and continues to flow the output current when detecting that the secondary battery is normal. 4. The charge control device according to claim 1, wherein when the short circuit is detected, the output current is controlled to flow intermittently. 5.   5. The control unit according to claim 1, wherein when the secondary battery is detected to be detached when the secondary battery is short-circuited, the control unit performs control so that the output current continues to flow. Charge control device.   An emergency lighting device comprising: the charging control device according to any one of claims 1 to 5; a light source; and a lighting circuit that turns on the light source by supplying power from the secondary battery. .

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