Emergency lighting device

Abstract

To provide an emergency lighting device which can charge a battery thereof with less circuit loss when a power-supply voltage is applied by a secondary of a switching circuit to activate a controlling microcomputer.SOLUTION: An emergency lighting device comprises a light source, a regular power-supply circuit to charge a battery for supplying power to the light source from an outside power source, an emergency power-supply circuit to light the light source using the battery by being activated when the outside power source is out, a controller to control the regular power-supply circuit, an activating power-supply to supply an activating power-supply voltage to activate the controller by a secondary of the regular power-supply circuit, and a battery voltage detector to detect a battery voltage of the battery and to input the battery voltage into the controller. The controller controls a voltage to a constant value as follows. When a value of the battery voltage is less than a first threshold indicating the activating power-supply voltage or more, an output voltage from the regular power-supply circuit is the activating power-supply voltage or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an emergency lighting device.

Background Art

[0002] Conventionally, in the event of a power outage during a disaster or accident such as a fire or earthquake at a place where a large number of unspecified people gather, an emergency lighting device that illuminates the interior may be used so that the people present can evacuate safely. The emergency lighting device is supplied with power from an external power source during normal use, charges a battery with the power, and supplies power from the charged battery to turn on a light source during an emergency when power is not supplied from the external power source.

[0003] In such an emergency lighting device, as a circuit configuration for realizing battery charging, there is one that generally combines a switching circuit and a linear regulator circuit for constant current control (for example, Patent Document 1).

[0004] In the circuit described in Patent Document 1, the circuit may become complicated to configure a linear regulator for constant current control, leading to an increase in cost. On the other hand, there is also a method of controlling the output of the switching circuit to a constant current and charging the battery at a constant current using only a limiting resistor without using a linear regulator for constant current control.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in a circuit that obtains the operating power supply voltage of the control microcomputer from the secondary side of the switching circuit, when charging a battery with a constant current using a limiting resistor, if the output voltage of the secondary side of the switching circuit is decreased, there is a problem that the operating power supply voltage of the control microcomputer cannot be obtained. Therefore, it is conceivable to make the output voltage sufficiently large in order to obtain the operating power supply voltage of the control microcomputer from the secondary side of the switching circuit. However, in that case, since it is necessary to increase the value of the limiting resistor, there is a problem that the circuit loss increases.

[0007] The present disclosure When the value is less than the first threshold indicating a value equal to or higher than the operating power supply voltage, the output voltage of the normal power supply circuit is controlled to be equal to or higher than the operating power supply voltage for constant voltage control. When the value of the battery voltage is equal to or higher than the second threshold indicating a fully charged battery voltage state, the normal power supply circuit is controlled for constant voltage control. When the value of the battery voltage is equal to or higher than the first threshold and less than the second threshold, the normal power supply circuit is controlled for constant current control. An object is to obtain an emergency lighting device that can suppress an increase in circuit loss and charge a battery.

Means for Solving the Problems

[0008] The emergency lighting device according to the present disclosure includes a light source unit, a normal power supply circuit that charges a battery that supplies power to the light source unit with an external power supply, an emergency power supply circuit that operates when there is a power outage of the external power supply and lights the light source unit with the battery, a control unit that controls the normal power supply circuit, an operating power supply unit that supplies an operating power supply voltage for operating the control unit from the output side of the normal power supply circuit, and a battery voltage detection unit that detects the battery voltage of the battery and inputs the battery voltage to the control unit. The control unit has a value of the battery voltage that

Figure 1

Effects of the Invention

[0009] According to the emergency lighting device according to the present disclosure, it is possible to suppress an increase in loss in a circuit that obtains the operating power supply voltage of the control microcomputer from the secondary side of the switching circuit and charge the battery.

Brief Description of the Drawings

[0010]

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals. Redundant descriptions will be appropriately simplified or omitted. Note that the present disclosure is not limited by the embodiments described below.

[0012] Embodiment 1. The emergency lighting device according to Embodiment 1 will be described below.

[0013] FIG. 1 is a circuit block diagram of the emergency lighting device 100 according to Embodiment 1. The emergency lighting device 100 includes a lighting unit 10 and a light source unit 30. The light source unit 30 is a light source for ensuring brightness in an emergency. The light source unit 30 is, for example, an LED. By using an LED as the light source unit 30, the energy consumption of the emergency lighting device 100 can be suppressed. The emergency lighting device 100 is equipped with a battery 50 to light the light source unit 30. The lighting unit 10 is supplied with power from an external power supply AC and charges the battery 50. The external power supply AC is an alternating current power supply. The battery 50 supplies power to the light source unit 30 in an emergency such as a power outage and lights the light source unit 30. The battery 50 may be any rechargeable battery, for example, a secondary battery such as a nickel-cadmium battery, a nickel-metal hydride battery, or a lithium-ion battery.

[0014] The lighting unit 10 includes a diode bridge 1, a normal power supply circuit 2, a battery voltage detection unit 4, a power outage detection circuit 5, an emergency power supply circuit 6, a control unit 7, and a notification unit 8.

[0015] The diode bridge 1 converts alternating current to direct current. The output of the diode bridge 1 is connected to the normal power supply circuit 2. The low potential side of the output of the diode bridge 1 is connected to the grounding terminal.

[0016] The normal power supply circuit 2 is composed of an isolated flyback circuit. The normal power supply circuit 2 is supplied with power from an external power supply AC during normal use and charges the battery 50. The normal power supply circuit 2 includes a capacitor 11, a capacitor 13, a capacitor 24, a resistor 12, a resistor 17, a resistor 22, a resistor 23, a transformer 14, a switching element 15, a control IC (Integrated Circuit) 16, a photocoupler 18, a pseudo power failure occurrence circuit 19, a diode 20, and an electrolytic capacitor 21.

[0017] In the normal power supply circuit 2, in order to reduce the full-wave of the external power supply AC and the ripple due to switching, a capacitor 11 is connected in parallel with the output of the diode bridge 1. One end of a resistor 12 and one end of the primary side of a transformer 14 are connected to the positive electrode of the capacitor 11.

[0018] The other end of the primary side of the transformer 14 is connected in series with the first terminal of the switching element 15. The second terminal of the switching element 15 is connected to the negative electrode of the capacitor 11. The control terminal of the switching element 15 is connected to the control IC 16. The control terminal is a terminal for switching between the first terminal and the second terminal. The control IC 16 controls the normal power supply circuit 2. Here, the normal use state means a state where the external power supply AC is not in a power failure state or a pseudo power failure state. In the following description, unless otherwise specified, the power failure state and the pseudo power failure state are collectively referred to as the power failure state.

[0019] The switching element 15 is, for example, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). When the switching element 15 is a MOSFET, the first terminal is the drain terminal, the second terminal is the source terminal, and the control terminal is the gate terminal. In the switching element 15, the first terminal is connected to the transformer 14, the second terminal is connected to the grounding terminal, and the control terminal is connected to the control IC 16.

[0020] The control IC 16 is, for example, a PFC (Power Factor Correction) driver. The control IC 16 drives the switching element 15. The circuit connected in the order of the resistor 12 and the capacitor 13 in parallel with the capacitor 11 supplies power to the control IC 16.

[0021] The photocoupler 18 is connected to the control IC 16 via the resistor 17. The resistor 17 and the photocoupler 18 are provided to input the information on the secondary side of the transformer 14 to the control IC 16.

[0022] The normal power supply circuit 2 includes a pseudo power outage generation circuit 19. The pseudo power outage generation circuit 19 is a circuit that can generate a pseudo power outage state. The pseudo power outage generation circuit 19 includes a pseudo power outage inspection switch, a remote control inspection button, etc. The pseudo power outage generation circuit 19 can, for example, trigger the operation of the control IC 16 by turning on the pseudo power outage inspection switch. Thereby, the pseudo power outage generation circuit 19 can create a pseudo power outage state. Therefore, it is possible to confirm whether the emergency lighting device 100 operates normally when the external power supply AC has a power outage.

[0023] One end of the flyback winding on the secondary side of the transformer 14 is connected to the anode of the diode 20. The diode 20 is connected in series to the secondary side of the transformer 14 and is provided to transmit a stable voltage to the output side. The positive electrode of the electrolytic capacitor 21 is connected to the cathode of the diode 20. The negative electrode of the electrolytic capacitor 21 is connected to the grounding terminal.

[0024] In the path for grounding the normal power supply circuit 2, the primary side and the secondary side of the transformer 14 are insulated by the capacitor 24.

[0025] The normal power supply circuit 2 includes a normal power supply output voltage detection unit. The normal power supply output voltage detection unit is composed of a resistor 22 and a resistor 23 connected in series. The normal power supply output voltage detection unit is connected in parallel with the electrolytic capacitor 21. The divided voltage value of the resistor 22 and the resistor 23 is input to the microcomputer which is the control unit 7. Thereby, the control unit 7 detects the output voltage of the normal power supply circuit 2.

[0026] The normal power supply circuit 2 which is a charging circuit charges the battery 50. The resistor 31 is connected between the flyback winding of the transformer 14 and the battery 50. The positive electrode of the battery 50 is connected to the other end of the resistor 31. The resistor 31 is connected in series with the battery 50 and is provided to limit the current of the battery 50. The negative electrode of the battery 50 is connected to the grounding terminal. That is, the resistor 31 and the battery 50 are connected in series to the output terminal of the normal power supply circuit 2.

[0027] The battery voltage detection unit 4 is composed of a resistor 51 and a resistor 52 connected in series. A series circuit of the resistor 51 and the resistor 52 is connected in parallel with the battery 50. Also, the battery voltage detection unit 4 is connected in parallel with the capacitor 32. The voltage obtained by dividing the battery voltage by the resistor 51 and the resistor 52 is input to the control unit 7. The control unit 7 calculates the potential difference between the output voltage of the normal power supply circuit 2 detected by the normal power supply output voltage detection unit and the voltage obtained by dividing the battery voltage by the resistor 51 and the resistor 52. The control unit 7 performs an operation based on the calculated potential difference and calculates the target value of the signal for turning on and off the switching element 15.

[0028] The control unit 7 outputs the target value of the signal for turning on and off the switching element 15 from the output terminal. A photocoupler 25 is connected to the output terminal of the control unit 7. The signal output from the control unit 7 is transmitted to the photocoupler 18 provided on the primary side of the transformer 14 via the photocoupler 25.

[0029] The output signal of the control unit 7 is transmitted to the control IC 16 via the photocoupler 18 and the resistor 17. The control IC 16 turns the switching element 15 on and off so that the target value of the output voltage matches the output voltage of the normal power supply circuit 2 according to the output signal received from the control unit 7. That is, the control unit 7 controls the normal power supply circuit 2 via the control IC 16. From the above, feedback control by the normal power supply circuit 2, which is an isolated flyback circuit, is realized.

[0030] The emergency power supply circuit 6 is composed of a boost switching circuit. The emergency power supply circuit 6 operates in an emergency such as a power outage of the external power supply AC, boosts the output voltage of the battery 50, and lights the light source unit 30. That is, the emergency power supply circuit 6 receives power supply from the battery 50, which is a DC power supply, and lights the light source unit 30.

[0031] A capacitor 32 is connected in parallel to the input terminal of the emergency power supply circuit 6. The positive electrode of the capacitor 32 is connected to the positive electrode of the battery 50 and one end of the coil 53. The negative electrode of the capacitor 32 is connected to the grounding terminal. The other end of the coil 53 is connected to the anode of the diode 54. The cathode of the diode 54 is connected to the positive electrode of the capacitor 58. The negative electrode of the capacitor 58 is connected to the negative electrode of the capacitor 32. That is, a series circuit connected in the order of the coil 53, the diode 54, and the capacitor 58 is connected in parallel to the capacitor 32.

[0032] A switching element 55 is connected between the connection point of the coil 53 and the diode 54 and the grounding terminal. The first terminal of the switching element 55 is connected to the anode of the diode 54. The second terminal of the switching element 55 is connected to the negative electrode of the capacitor 58. The control terminal of the switching element is connected to the control unit 7. The switching element 55 is, for example, a MOSFET.

[0033] The anode side of the light source unit 30 is connected to the positive electrode of the capacitor 58. One end of the resistor 59 is connected to the cathode side of the light source unit 30. The other end of the resistor 59 is connected to the negative electrode of the capacitor 58. In FIG. 1, two LEDs are shown as the light source unit 30, but the number of light sources provided in the emergency lighting device 100 may be one or more.

[0034] The power failure detection circuit 5 is a circuit that detects the power failure state of the external power supply AC. The power failure detection circuit 5 monitors whether the external power supply AC is in a power failure state based on a signal of the output voltage from one end of the flyback winding on the secondary side of the transformer 14, and detects the power failure state of the external power supply AC. The power failure detection circuit 5 is connected to the control unit 7. When the power failure detection circuit 5 detects a power failure of the external power supply AC, it transmits a signal indicating that the external power supply AC is in a power failure state to the control unit 7. When receiving the signal from the power failure detection circuit, the control unit 7 operates the emergency power supply circuit 6. That is, the control unit 7 controls the emergency power supply circuit 6.

[0035] The emergency power supply circuit 6 includes an emergency power supply output voltage detection unit. The emergency power supply output voltage detection unit is composed of a resistor 56 and a resistor 57 connected in series. The emergency power supply output voltage detection unit is connected in parallel with the capacitor 58. The divided voltage value of the resistor 56 and the resistor 57 is input to the control unit 7. Thereby, the control unit 7 detects the output voltage of the emergency power supply circuit 6.

[0036] The emergency power supply circuit 6 includes an output current detection unit. The output current detection unit is composed of a resistor 59 connected to the cathode side of the LED. When the emergency power supply circuit 6 operates, a voltage obtained by boosting the output voltage of the battery 50 is applied to the capacitor 58. The voltage applied to the capacitor 58 is the output voltage of the emergency power supply circuit 6. A voltage corresponding to the current flowing through the light source unit 30 is applied to the resistor 59. The voltage applied to the resistor 59 is input to the control unit 7. Thereby, the control unit 7 detects the output current of the emergency power supply circuit 6. By setting the target value of the output current with the output voltage detected by the emergency power supply output voltage detection unit, constant power feedback control is performed. In this way, the power of the light source unit 30 is controlled to be constant.

[0037] Next, the control unit 7 will be described. The control unit 7 is composed of a microcomputer. The microcomputer includes a CPU that performs various operations, a memory, and a timer. The memory is composed of, for example, a non-volatile memory.

[0038] The control unit 7 transmits a signal indicating the state of the connected battery 50 to the notification unit 8. When receiving the signal from the control unit 7, the notification unit 8 notifies the state of the battery 50 outside the emergency lighting device 100. The notification unit 8 is, for example, a notification LED. By flashing the LED, it notifies the outside that the state of the battery 50 is abnormal. Also, the notification unit 8 lights up the notification LED to notify the outside that the state of the battery 50 is normal. Further, the notification unit 8 turns off the notification LED to notify the outside that the battery 50 is not connected.

[0039] When notifying the state of the battery 50 to the outside, a charging LED for notifying whether charging is being performed by the normal power supply circuit 2 may be used. By doing so, there is no need to newly add an LED as the notification unit 8. Note that the notification unit 8 is not limited to the notification LED, and may be, for example, a sound output unit that outputs sound or voice, such as a speaker, and the same applies to other forms described below.

[0040] Next, the operating power supply unit 3 will be described. The operating power supply unit 3 supplies power to the microcomputer that is the control unit 7. The operating power supply unit 3 supplies a power voltage for operating the control unit 7 from the output side of the normal power supply circuit 2. The operating power supply unit 3 is composed of a diode 33 and a regulator 34. The diode 33 is provided on the line for supplying power from the normal power supply circuit 2 to the control unit 7. The anode of the diode 33 is connected to the output side of the normal power supply circuit 2. That is, the anode of the diode 33 is connected to one end of the flyback winding on the secondary side of the transformer 14. The diode 33 is connected in series with the diode 20 and is provided to transmit a stable voltage to the output side.

[0041] The cathode of the diode 33 is connected to the control unit 7 side on the line that supplies power from the normal power supply circuit 2 to the control unit 7. Specifically, the cathode of the diode 33 is connected to the regulator 34. The regulator 34 is provided between the diode 33 and the control unit 7. That is, the regulator 34 is provided between the cathode of the diode 33 and the control unit 7. The output of the regulator 34 is connected to the power supply terminal of the control unit 7. The regulator 34 stabilizes the output voltage output from the diode 33. That is, the control unit 7 operates by obtaining power from the operating power supply unit 3. Here, let the operating power supply voltage for operating the control unit 7 be Vcc.

[0042] The control unit 7 compares the divided value of the battery voltage input from the battery voltage detection unit 4 with a threshold value programmed in advance, and controls the output voltage of the normal power supply circuit 2. Note that the threshold value may be stored in the memory of the microcomputer, and the control unit 7 may read the threshold value from the memory and compare it with the divided value of the battery voltage. Hereinafter, the control unit 7 will be described on the assumption that the threshold value is stored in the memory in advance.

[0043] FIG. 2 and FIG. 3 are diagrams for explaining the output of the normal power supply circuit 2 according to Embodiment 1. FIG. 2A shows the relationship between voltage and time, and FIG. 2B shows the relationship between current and time. Also, FIG. 3A shows the relationship between voltage and time, and FIG. 3B shows the relationship between current and time. Here, let the output voltage of the normal power supply circuit 2 be Vout, the battery voltage detected by the battery voltage detection unit 4 be Vbat, and the threshold value regarding the voltage stored in the control unit 7 in advance be the first threshold value Vth1. Also, let the current for charging the battery 50 be the charging current Ibat.

[0044] A case where the battery 50 is charged by the normal power supply circuit 2 will be described. In the following description, the first threshold value Vth1 is a value that is equal to or higher than the operating power supply voltage Vcc for operating the control unit 7. Specifically, the first threshold value Vth1 is the voltage obtained by subtracting the forward voltage Vf that drops in the diode 33 and the voltage that drops in the regulator 34 from the output voltage Vout of the normal power supply circuit 2.

[0045] When the battery voltage Vbat is less than the first threshold Vth1, since it is necessary to charge the battery 50, the control unit 7 sets the feedback target voltage so that the output voltage Vout of the main power supply circuit 2 becomes constant and performs control. At this time, as shown in FIG. 2B, since the main power supply circuit 2 performs constant voltage control, the charging current Ibat is in a higher state compared to the case of performing constant current control.

[0046] When charging the battery 50 by constant current control when the battery voltage Vbat is less than the first threshold Vth1, if the output voltage Vout of the main power supply circuit 2 is decreased, the operating power supply voltage Vcc cannot be ensured. However, as described above, by setting the first threshold Vth1 to be equal to or higher than the operating power supply voltage Vcc and performing constant voltage control, the operating power supply voltage Vcc can be ensured. In other words, since constant voltage control is performed with the output voltage Vout being equal to or higher than the operating power supply voltage Vcc, the operating power supply voltage Vcc can be ensured. Therefore, in order to ensure the operating power supply voltage Vcc from the output voltage Vout of the main power supply circuit 2, that is, in order to increase the output voltage Vout, it is not necessary to increase the value of the resistor 31, so an increase in the loss in the circuit can be suppressed. That is, the battery 50 can be charged with high efficiency.

[0047] When the battery voltage Vbat rises by charging the battery 50 and becomes equal to or higher than the first threshold Vth1, the control unit 7 sets the feedback target voltage so that the voltage across the resistor 31 becomes constant and performs control. At this time, since the main power supply circuit 2 performs constant current control, the charging current Ibat flowing through the battery 50 becomes constant. In this way, since the control unit 7 controls so that the charging current Ibat becomes constant, the charging current Ibat does not flow excessively when the battery 50 is near full charge, and it is possible to suppress the battery 50 from entering an overcharged state. Note that when the battery voltage Vbat is equal to or higher than the first threshold Vth1, it is not always necessary to set the main power supply circuit 2 to constant current control.

[0048] Next, FIG. 3 will be described. When the battery voltage Vbat drops below the first threshold Vth1, the control unit 7 sets the feedback target voltage so that the output voltage Vout of the normal power supply circuit 2 becomes constant and performs control. At this time, as shown in FIG. 3B, since the normal power supply circuit 2 performs constant voltage control, Ibat is in a higher state compared to the case of performing constant current control.

[0049] The normal power supply circuit 2 is set so that the first threshold Vth1 is equal to or higher than the operating power supply voltage Vcc, and the operating power supply voltage Vcc can be ensured by performing constant voltage control.

[0050] As described above, by switching the output voltage Vout of the normal power supply circuit 2 between constant voltage control and constant current control according to the value of the battery voltage Vbat, it is possible to suppress an increase in losses in the circuit and obtain an emergency lighting device that can charge the battery 50 with high efficiency.

[0051] As described above, the emergency lighting device 100 according to Embodiment 1 includes a light source unit 30, a normal power supply circuit 2 that charges a battery 50 that supplies power to the light source unit 30 with an external power supply AC, an emergency power supply circuit 6 that operates when there is a power outage of the external power supply AC and lights the light source unit 30 with the battery 50, a control unit 7 that controls the normal power supply circuit 2, an operating power supply unit 3 that supplies an operating power supply voltage for operating the control unit 7 from the output side of the normal power supply circuit 2, and a battery voltage detection unit 4 that detects the battery voltage of the battery 50 and inputs the battery voltage to the control unit 7. The control unit 7 is an emergency lighting device 100 that performs constant voltage control on the normal power supply circuit 2 when the value of the battery voltage is less than the first threshold that is a value equal to or higher than the power supply voltage.

[0052] According to such a configuration, it is possible to suppress an increase in losses in a circuit that obtains the operating power supply voltage of the control microcomputer from the secondary side of the switching circuit, and it is possible to charge the battery 50 with high efficiency.

[0053] Further, the emergency lighting device 100 may be configured to perform constant current control on the normal power supply circuit 2 when the value of the battery voltage is equal to or higher than the first threshold.

[0054] According to such a configuration, when the battery 50 is near full charge, the charging current Ibat does not flow excessively, and it is possible to suppress the battery 50 from entering an overcharged state.

[0055] Embodiment 2. Next, the emergency lighting device 100 according to Embodiment 2 will be described. FIGS. 4 and 5 are diagrams for explaining the output of the normal power supply circuit 2 according to Embodiment 2. In the following description, the configuration different from that of Embodiment 1 will be mainly described. The emergency lighting device 100 according to Embodiment 2 is different from the emergency lighting device 100 of Embodiment 1 in that the control unit 7 stores the second threshold value Vth2 in the memory, and the other configurations are the same as those of Embodiment 1, so the description thereof will be omitted.

[0056] The control unit 7 stores the first threshold value Vth1 and the second threshold value Vth2 in the memory in advance. The second threshold value Vth2 is a threshold value larger than the first threshold value Vth1. FIGS. 4 and 5 show the first threshold value Vth1 and the second threshold value Vth2, respectively.

[0057] FIG. 4 is a diagram for explaining the output of the normal power supply circuit 2 according to Embodiment 2. FIG. 4 shows the transition of charging the battery 50 by the normal power supply circuit 2 until the battery voltage Vbat exceeds the second threshold value Vth2.

[0058] The second threshold value Vth2 is a value indicating the state of the battery voltage when the battery 50 is fully charged. Here, full charge includes not only the state where the battery 50 is completely charged, but also the state where the voltage is 80% or more of the voltage in the completely charged state of the battery 50.

[0059] When the battery voltage Vbat is equal to or higher than the first threshold value and lower than the second threshold value, the control unit 7 sets a feedback target voltage so that the voltage across the resistor 31 becomes constant, and performs control. At this time, since the normal power supply circuit 2 performs constant current control, the charging current Ibat flowing through the battery 50 becomes constant. Note that the case where the battery voltage Vbat is lower than the first threshold value Vth1 is the same as that in the first embodiment, and thus will be omitted. This also applies to FIG. 5 described below.

[0060] When the battery voltage Vbat rises and becomes equal to or higher than the second threshold value, the control unit 7 sets a feedback target voltage so that the output voltage of the normal power supply circuit 2 becomes constant, and performs control. At this time, since the normal power supply circuit 2 performs constant voltage control, the charging current Ibat decreases.

[0061] For example, when the battery 50 is in an unconnected state, a phenomenon occurs in which the battery voltage Vbat detected by the battery voltage detection unit 4 indicates a value that is substantially equal to or close to the output voltage Vout of the normal power supply circuit 2. However, when the battery voltage is fully charged, since the normal power supply circuit 2 performs constant voltage control, an overvoltage state does not occur even when the battery 50 is unconnected.

[0062] Subsequently, FIG. 5 will be described. When the battery voltage Vbat drops and falls below the second threshold value Vth2, the control unit 7 sets a feedback target voltage so that the voltage across the resistor 31 becomes constant, and performs control. At this time, as shown in FIG. 5B, since the normal power supply circuit 2 performs constant current control, the charging current Ibat becomes constant.

[0063] As described above, in the emergency lighting device 100 according to the second embodiment, when the value of the battery voltage Vbat is equal to or higher than the second threshold value Vth2 indicating the state of the fully charged battery voltage Vbat, the control unit 7 performs constant voltage control on the normal power supply circuit 2, and when the value of the battery voltage Vbat is equal to or higher than the first threshold value Vth1 and lower than the second threshold value Vth2, the control unit 7 is an emergency lighting device 100 that performs constant current control on the normal power supply circuit 2.

[0064] According to such a configuration, when the battery voltage is fully charged, since the normal power supply circuit 2 is under constant voltage control, even when the battery 50 is not connected, an overvoltage state will not occur.

[0065] As described above, the embodiments of the present disclosure have been explained. However, the emergency lighting device 100 of the present disclosure is not limited to the forms described in Embodiment 1 and Embodiment 2, and shows a part of the content of the present disclosure. The emergency lighting device of the present disclosure can also be combined with other known technologies, and within the scope not departing from the gist of the present disclosure, it is also possible to omit or change a part of the configuration, such as appropriately combining them.

Explanation of Reference Numerals

[0066] 1 Diode bridge, 2 Normal power supply circuit, 3 Operating power supply unit, 4 Battery voltage detection unit, 5 Power failure detection circuit, 6 Emergency power supply circuit, 7 Control unit, 8 Notification unit, 10 Lighting unit, 11 Capacitor, 12 Resistor, 13 Capacitor, 14 Transformer, 15 Switching element, 16 Control IC, 17 Resistor, 18 Photo coupler, 19 Pseudo power failure generation circuit, 20 Diode, 21 Electrolytic capacitor, 22 Resistor, 23 Resistor, 24 Capacitor, 25 Photo coupler, 30 Light source unit, 31 Resistor, 32 Capacitor, 33 Diode, 34 Regulator, 50 Battery, 51 Resistor, 52 Resistor, 53 Coil, 54 Diode, 55 Switching element, 56 Resistor, 57 Resistor, 58 Capacitor, 59 Resistor, 100 Emergency lighting device

Claims

1. A light source unit, A normal power supply circuit that charges a battery that supplies power to the light source unit with an external power supply, An emergency power supply circuit that operates when a power outage occurs in the external power supply and lights the light source unit with the battery, A control unit that controls the normal power supply circuit, An operating power supply unit that supplies an operating power supply voltage for operating the control unit from the output side of the normal power supply circuit, A battery voltage detection unit that detects the battery voltage of the battery and inputs the battery voltage to the control unit, Comprising, The control unit, When the value of the battery voltage is less than a first threshold value indicating a value equal to or higher than the operating power supply voltage, constant voltage control is performed so that the output voltage of the normal power supply circuit is equal to or higher than the operating power supply voltage, When the value of the battery voltage is equal to or higher than a second threshold value indicating the state of the fully charged battery voltage, constant voltage control is performed on the normal power supply circuit, An emergency lighting device that performs constant current control on the normal power supply circuit when the value of the battery voltage is equal to or higher than the first threshold value and less than the second threshold value.

2. The emergency lighting device according to claim 1, further comprising a diode provided on a line for supplying power from the normal power supply circuit to the control unit, with the anode connected to the output side of the normal power supply circuit and the cathode connected to the control unit side.

3. The emergency lighting device according to claim 2, further comprising a regulator provided between the diode and the control unit.

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