JP7019989B2 - Disaster prevention light lighting device and disaster prevention light - Google Patents

Description

The present invention relates to a disaster prevention light lighting device and a disaster prevention light.

Patent Document 1 discloses a charging device including a constant voltage generating means and a constant current charging means. The charging device charges the secondary battery. The output voltage of the constant voltage generating means rises as the voltage of the secondary battery rises. This prevents an unnecessarily large potential difference in the input / output voltage of the constant current charging means. Therefore, the charging efficiency can be improved.

Japanese Unexamined Patent Publication No. 5-308733

Generally, in a charging circuit provided with a constant current circuit such as a linear constant current circuit, a potential difference is required between the input and the output of the constant current circuit. The input of the constant current circuit is connected to the charging power supply, and the output of the constant current circuit is connected to the battery. That is, it is necessary to prepare a charging power source having a voltage higher than the maximum value of the battery voltage. Generally, a potential difference of, for example, about 3 V or more is required between the charging power supply and the battery voltage.

In the disaster prevention light lighting device, the maximum value of the battery voltage may decrease due to deterioration over time. When the maximum value of the battery voltage decreases, the potential difference between the battery and the charging power source increases. This may increase the power consumption of the constant current circuit. On the other hand, in the charging device shown in Patent Document 1, control is assumed when the battery voltage rises due to charging, and the case where the battery voltage drops is not considered.

Further, in general, in a disaster prevention light lighting device, the change range of the battery voltage tends to be large. Therefore, when the charging device shown in Patent Document 1 is applied to the disaster prevention light lighting device, there is a possibility that the power failure detection cannot be stably performed due to the decrease in the battery voltage. Further, it may be difficult to secure a power source for a control circuit or the like.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a disaster prevention light lighting device and a disaster prevention light capable of suppressing a decrease in charging efficiency with respect to a decrease in battery voltage.

The disaster prevention light lighting device according to the present invention has a power supply circuit that generates a charging power source, a constant current circuit that receives power from the charging power source and outputs a charging current, and is charged by the charging current to turn on a lamp in the event of a power failure. A power failure detection circuit that detects a power failure by detecting the battery to be turned on and the interruption of the charging power supply, and a battery voltage generated at both ends of the battery are detected, and the charging power supply is subjected to a change in the battery voltage. The control circuit includes a control circuit that continuously changes the voltage and controls the power supply circuit so that the voltage of the charging power supply is lowered as the battery voltage is lowered. The control circuit is external to the power supply circuit. When power is supplied from, power is supplied from the charging power supply, and power is supplied from the battery in the event of a power failure.

In the disaster prevention light lighting device according to the present invention, the control circuit lowers the voltage of the charging power source as the battery voltage decreases. Therefore, it is possible to suppress a decrease in charging efficiency with respect to a decrease in battery voltage.

It is a circuit block part of the disaster prevention light which concerns on Embodiment 1. It is a figure explaining the operation of the disaster prevention light which concerns on Embodiment 1. FIG. It is a circuit block diagram of the disaster prevention light which concerns on Embodiment 2. FIG. It is a figure explaining the operation of the disaster prevention light which concerns on Embodiment 2.

The disaster prevention light lighting device and the disaster prevention light according to the embodiment of the present invention will be described with reference to the drawings. The same or corresponding components may be designated by the same reference numerals and the description may be omitted.

Embodiment 1.
FIG. 1 is a circuit block portion of the disaster prevention light 100 according to the first embodiment. The disaster prevention light 100 includes a disaster prevention light lighting device 50 and a lamp 6. The disaster prevention light lighting device 50 lights the lamp 6 in the event of a power failure. The disaster prevention light lighting device 50 is connected to the commercial power source 1. During normal use, the disaster prevention light lighting device 50 receives power from the commercial power source 1. Civil time indicates a state in which the disaster prevention light lighting device 50 is energized from the commercial power source 1.

The power supply circuit 2 is a flyback circuit. The power supply circuit 2 is supplied with power from the commercial power supply 1 to generate a charging power supply. The voltage of the charging power supply is Vf. The power supply circuit 2 is not limited to the flyback circuit, and any circuit that can generate a charging power supply by receiving power from the commercial power supply 1 can be adopted. Further, in the present embodiment, the commercial power source 1 is an AC power source. Not limited to this, the commercial power supply 1 may be a DC power supply or the like.

A constant current circuit 3 is connected to the power supply circuit 2 via a disconnection circuit 10. The constant current circuit 3 receives power from the charging power source and outputs the charging current Ic. The constant current circuit 3 has a detection resistor. When the charging current Ic flows through the detection resistor, a voltage is generated across the detection resistor. The constant current circuit 3 is controlled so that this voltage becomes constant. That is, in the constant current circuit 3, the output voltage is controlled so that the charging current Ic becomes constant.

The voltage Vf of the charging power supply is stepped down by the constant current circuit 3. The output voltage of the constant current circuit 3 corresponds to the battery voltage Vb generated across the battery 4. The constant current circuit 3 outputs a stabilized current using a charging power source as a power source.

The disaster prevention light lighting device 50 includes a battery 4. The battery 4 is charged by the charging current Ic. A booster circuit 5 is connected to the battery 4. In the event of a power failure, the battery 4 supplies power to the booster circuit 5. The booster circuit 5 turns on the lamp 6. Therefore, the battery 4 turns on the lamp 6 in the event of a power failure. Here, the term “power failure” indicates a state in which the supply of electric power from the commercial power supply 1 to the power supply circuit 2 is cut off in an emergency.

A power failure detection circuit 11 is connected to the output of the power supply circuit 2. The power failure detection circuit 11 detects the energization and power failure of the commercial power supply 1 by detecting the output voltage of the power supply circuit 2. The power failure detection circuit 11 detects a power failure by detecting the interruption of the charging power supply. Further, since the voltage Vf of the charging power supply is normally output, the power failure detection circuit 11 detects the energization of the commercial power supply 1.

A control circuit 7 is connected to the output of the power failure detection circuit 11. The detection result of energization or power failure of the commercial power supply 1 is transmitted from the power failure detection circuit 11 to the control circuit 7. As a result, the control circuit 7 detects the energization or power failure of the commercial power supply 1.

A diode anode is connected to the output of the power supply circuit 2. The input of the linear power supply 8 is connected to the cathode of the diode. A control circuit 7 and a booster circuit 5 are connected to the output of the linear power supply 8. The linear power supply 8 steps down the voltage Vf of the charging power supply to generate the voltage Vc of the control power supply. The control power supply is the power supply of the control circuit 7. In this way, when the power supply circuit 2 is supplied with power from the outside, the power is supplied to the control circuit 7 from the charging power supply.

The power from the control power supply is also supplied to the booster circuit 5. The control power supply may be supplied from the control power supply to, for example, an IC included in the booster circuit 5.

The input of the boost power supply 9 is connected to the battery 4. The output of the boost power supply 9 is connected to the input of the linear power supply 8. At the time of a power failure, the battery voltage Vb applied to both ends of the battery 4 is boosted by the boost power supply 9 and input to the linear power supply 8. The battery voltage Vb is supplied to the control circuit 7 via the boost power supply 9 and the linear power supply 8. Therefore, in the event of a power failure, power is supplied to the control circuit 7 from the battery 4.

The disaster prevention light 100 has an inspection function. The disconnection circuit 10 cuts off the supply of electric power from the charging power supply to the constant current circuit 3 when the disaster prevention light lighting device 50 is inspected. The inspection is carried out in a state where the commercial power source 1 is energized except during a power failure. The disaster prevention light 100 includes an inspection switch. At the time of inspection, the operator operates the inspection switch. This turns on the inspection function.

When the inspection function is turned on, the control circuit 7 controls the disconnection circuit 10. As a result, the current path from the power supply circuit 2 to the constant current circuit 3 is cut off. Therefore, the charging operation from the commercial power source 1 to the battery 4 is stopped, and a power failure is simulated. In the inspection, the lamp 6 is turned on by the power supply from the battery 4, as in the case of a power failure. Therefore, the operation of the disaster prevention light 100 can be confirmed. At the time of inspection, the control circuit 7 operates by being supplied with electric power from the charging power source.

The control circuit 7 detects the battery voltage Vb generated at both ends of the battery 4. The control circuit 7 outputs a control signal according to the battery voltage Vb, and controls the output voltage of the power supply circuit 2. The control circuit 7 controls the power supply circuit 2 so that the voltage Vf of the charging power supply decreases as the battery voltage Vb decreases.

The control circuit 7 controls so that the voltage Vf of the charging power supply is higher than the battery voltage Vb by a constant voltage. In this embodiment, the voltage Vf is controlled to be 1 V higher than the battery voltage Vb. Not limited to this, the voltage Vf may be a voltage higher than the battery voltage Vb.

The output of the control circuit 7 is connected to the input of the voltage control circuit 12. The voltage control circuit 12 outputs a signal for controlling the voltage Vf according to the control signal output by the control circuit 7. The control circuit 7 controls the charging power supply via the voltage control circuit 12.

The disaster prevention light lighting device 50 includes a limiter circuit 13. The limiter circuit 13 is connected to the output of the voltage control circuit 12. The output of the limiter circuit 13 is connected to the power supply circuit 2. The limiter circuit 13 limits the signal output by the voltage control circuit 12 so that the power supply circuit 2 outputs a voltage Vf equal to or higher than the first voltage V1. That is, the limiter circuit 13 maintains the voltage Vf of the charging power supply at the first voltage V1 or higher.

FIG. 2 is a diagram illustrating the operation of the disaster prevention light 100 according to the first embodiment. The control of the power supply circuit 2 by the control circuit 7 will be described with reference to FIG. Generally, the maximum value of the battery voltage Vb decreases due to aged deterioration. The battery voltage Vb of the disaster prevention light 100 newly provided at time t1 decreases with the passage of time as shown in FIG. 2 at time t2. In the present embodiment, the control circuit 7 lowers the voltage Vf of the charging power supply as the battery voltage Vb drops due to aged deterioration. Therefore, at times t1 to t2, the voltage Vf decreases so that the difference between the voltage Vf and the battery voltage Vb maintains 1V.

It is assumed that a power failure occurs at times t2 to t3. At this time, the lamp 6 is turned on by the battery 4. Therefore, the battery voltage Vb drops due to the discharge of the battery 4. At this time, power is supplied to the control circuit 7 from the battery 4. Further, the voltage Vf at the time of a power failure is zero.

It is assumed that the power failure is resolved from time t3 to t4 and the power supply from the commercial power source 1 to the disaster prevention light lighting device 50 is restored. As a result, the battery 4 is charged again. Therefore, at time t4, the battery voltage Vb is restored. At this time, power is supplied to the control circuit 7 from the charging power source.

Here, the minimum value of the battery voltage Vb at the time when the power failure is resolved may be 0V. Therefore, if the voltage Vf is set to be 1 V higher than the battery voltage Vb regardless of the value of the battery voltage Vb, the voltage Vf becomes at least 1 V. Therefore, the input voltage of the linear power supply 8 may be insufficient and the control power supply may not be secured. On the other hand, the limiter circuit 13 maintains the voltage Vf of the charging power supply at the first voltage V1 or higher. The first voltage V1 is the lowest voltage Vf to which electric power is supplied from the charging power source and the control circuit 7 operates. As shown in FIG. 2, in the region where the battery voltage Vb is the second voltage V2 or less, the voltage Vf is maintained at the first voltage V1 even if the battery voltage Vb drops. As a result, it is possible to prevent the voltage Vf of the charging power supply from dropping to a voltage at which the output voltage of the linear power supply 8 is insufficient. Therefore, a control power supply can be secured.

The constant current circuit 3 consumes power obtained by multiplying the difference between the voltage Vf of the charging power supply and the battery voltage Vb and the charging current Ic. Therefore, if the voltage Vf is constant regardless of the battery voltage Vb, the power consumption becomes large especially when the battery voltage Vb drops. As a result, the amount of heat generated by the disaster prevention light lighting device 50 increases. In particular, when the battery voltage Vb drops due to aged deterioration, the difference from the voltage Vf becomes large, so that it may be necessary to take measures so that the disaster prevention light lighting device 50 does not break down.

On the other hand, in the present embodiment, the voltage Vf of the charging power supply is variable. The control circuit 7 changes the voltage Vf according to the battery voltage Vb of the battery 4, which is the load of the constant current circuit 3. By lowering the voltage Vf as the battery voltage Vb is lower, the difference between the voltage Vf and the battery voltage Vb can be reduced in the region where the battery voltage Vb is low, as compared with the case where the voltage Vf is constant. Therefore, the power consumption of the disaster prevention light lighting device 50 can be reduced.

In particular, when the maximum voltage of the battery voltage Vb decreases due to aged deterioration, it is possible to suppress the decrease in charging efficiency. In addition, it is possible to suppress the failure of the disaster prevention light 100 due to deterioration over time.

Further, in order to suppress the temperature rise of the device, it is generally necessary to use a heat radiating circuit using a heat radiating component or a heat radiating member such as a heat radiating pad. In the present embodiment, the heat generation of the disaster prevention light lighting device 50 can be suppressed by reducing the power consumption of the disaster prevention light lighting device 50. Therefore, the use of a heat dissipation circuit or a heat dissipation member can be reduced. Therefore, the disaster prevention light lighting device 50 can be miniaturized. In addition, the manufacturing cost of the disaster prevention light lighting device 50 can be reduced.

Further, in the present embodiment, the control power supply can be secured by the limiter circuit 13 even when the voltage Vf of the charging power supply drops. As a result, the control circuit 7 can be operated stably. Therefore, the power supply circuit 2 can be controlled stably. In particular, in the disaster prevention light 100, the battery voltage Vb fluctuates in a wide range. In the present embodiment, the control circuit 7 can be operated stably even if the battery voltage Vb fluctuates in a wide range.

Further, if the voltage Vf of the charging power supply drops excessively, the power failure detection circuit 11 may erroneously detect the interruption of the charging power supply. Therefore, the power failure detection circuit 11 may malfunction. In this embodiment, the voltage Vf is maintained at the first voltage V1 or higher. Therefore, it is possible to prevent erroneous detection of a power failure and stably perform power failure detection. Here, it is assumed that the first voltage V1 is set higher than the voltage at which the power failure detection circuit 11 determines that the charging power supply is cut off.

Further, in the present embodiment, the inspection can be performed by stopping the charging of the battery 4 by the disconnection circuit 10. Therefore, the inspection work can be easily carried out.

In the present embodiment, the voltage Vf is maintained at the first voltage V1 in the region where the battery voltage Vb is the second voltage V2 or less. Not limited to this, the voltage Vf may be maintained at the first voltage V1 or higher. Further, in the present embodiment, the voltage Vf of the charging power supply is set to be higher than the battery voltage Vb by a constant voltage. As an example of this modification, the difference between the voltage Vf of the charging power supply and the battery voltage Vb does not have to be constant.

These modifications can be appropriately applied to the disaster prevention light lighting device and the disaster prevention light according to the following embodiments. Since the disaster prevention light lighting device and the disaster prevention light according to the following embodiments have much in common with the first embodiment, the differences from the first embodiment will be mainly described.

Embodiment 2.
FIG. 3 is a circuit block diagram of the disaster prevention light 200 according to the second embodiment. The disaster prevention light 200 includes a disaster prevention light lighting device 250. In the disaster prevention light lighting device 250, the constant current circuit is a resistance 14. The cutting circuit is a diode 15. In the diode 15, the power supply circuit 2 is connected to the anode and the resistor 14 is connected to the cathode.

The constant current circuit 3 of the first embodiment is controlled so that the voltage applied to the detection resistor becomes constant. Here, by controlling the output voltage of the power supply circuit 2, the charging current Ic can be maintained at a constant current even if the constant current circuit 3 is replaced with the resistance 14.

Further, when inspecting the disaster prevention light lighting device 50, the control circuit 7 lowers the voltage Vf of the charging power supply to be lower than the battery voltage Vb. As a result, the current flowing through the resistor 14 is cut off by the diode 15. Therefore, the supply of electric power from the charging power source to the resistor 14 is cut off. As a result, the operation of the disaster prevention light 100 can be confirmed. At this time, the voltage Vc of the control power supply may be insufficient due to the decrease in the voltage Vf. In this case, power is supplied from the battery 4 to the control power supply via the step-up power supply 9 during the inspection as in the case of a power failure.

In the first embodiment, a potential difference of about 1 to 3 V is required across the constant current circuit 3 due to the limitation of the internal circuit of the constant current circuit 3. On the other hand, when the constant current circuit is a resistor 14, there is no limit to the potential difference between both ends of the resistor 14. Therefore, the power consumption of the resistor 14 can be suppressed by adjusting the resistance value.

For example, the potential difference between both ends of the resistor 14 is 3V, and the resistance value is 30Ω. At this time, a constant current of 100 mA is obtained as the charging current Ic. Further, the power consumption of the resistor 14 is 3V × 0.1A = 0.3W. On the other hand, even if the potential difference is 1 V and the resistance value is 10 Ω, a constant current of 100 mA can be obtained in the same manner. However, the power consumption of the resistor 14 is 1V × 0.1A = 0.1W, which is reduced to 1/3 of the case where the potential difference is 3V and the resistance value is 30Ω.

However, if the resistance value of the resistor 14 is reduced, the voltage that can be applied to the resistor 14 becomes smaller. Therefore, if the voltage Vf is kept constant by the limiter circuit 13, particularly when the battery voltage Vb drops, heat generation increases. Therefore, it is preferable to set the first voltage V1b at which the limiter circuit 13 operates as low as possible.

FIG. 4 is a diagram illustrating the operation of the disaster prevention light 200 according to the second embodiment. In the present embodiment, when the battery voltage Vb becomes lower than the second voltage V2 in a state where the power supply circuit 2 is supplied with power from the outside, the power is supplied to the control circuit 7 from the battery 4. The second voltage V2 is the battery voltage Vb when the charging power supply voltage Vf = V1a. The voltage V1a is the lowest voltage Vf to which power is supplied from the charging power source and the control circuit 7 operates.

In the present embodiment, when the power supply from the charging power supply to the control power supply is insufficient, the boost power supply 9 used in an emergency is used to supply power from the battery 4 to the control power supply. Here, the boost power supply 9 cannot be boosted when the battery voltage Vb is 0V. Therefore, the limiter circuit 13 maintains the voltage Vf of the charging power supply at the first voltage V1b or higher. The first voltage V1b is the lowest voltage Vf to which power is supplied from the charging power source and the step-up power source 9 operates. In the region where the battery voltage Vb is the third voltage V3 or less, the voltage Vf is maintained at the first voltage V1b even if the battery voltage Vb drops.

From the above, the first voltage V1b in which the limiter circuit 13 operates can be set lower than that in the first embodiment. That is, the control of lowering the voltage Vf as the battery voltage Vb decreases can be performed up to a region where the voltage Vf is lower than that of the first embodiment. Therefore, even when the constant current circuit has a resistor 14, heat generation can be suppressed.

In the present embodiment, the constant current circuit and the cutting circuit can be simplified as compared with the first embodiment. On the other hand, in the present embodiment, the performance such as reduction of power consumption and the inspection function can be maintained as in the first embodiment. Further, by reducing the resistance value of the resistor 14, the power consumption of the resistor 14 can be suppressed.

The technical features described in each embodiment may be used in combination as appropriate.

100, 200 disaster prevention light, 50, 250 disaster prevention light lighting device, 2 power supply circuit, 3 constant current circuit, 4 battery, 6 lamp, 7 control circuit, 10 disconnection circuit, 11 power failure detection circuit, 13 limiter circuit, 14 resistance, 15 Diode, Ic charging current, V1 1st voltage, V2 2nd voltage, Vb battery voltage, Vf voltage

Claims (10)

A power supply circuit that generates a charging power supply and
A constant current circuit that receives power from the charging power supply and outputs the charging current,
A battery that is charged by the charging current and turns on the lamp in the event of a power failure,
A power failure detection circuit that detects a power failure by detecting the interruption of the charging power supply,
The battery voltage generated at both ends of the battery is detected, the voltage of the charging power supply is continuously changed with respect to the change of the battery voltage, and the voltage of the charging power supply is lowered as the battery voltage is lowered. The control circuit that controls the power supply circuit and
Equipped with
The control circuit is a disaster prevention light lighting device, characterized in that power is supplied from the charging power source when power is supplied to the power supply circuit from the outside, and power is supplied from the battery in the event of a power failure. The disaster prevention light lighting device according to claim 1, wherein the control circuit reduces the voltage of the charging power supply as the battery voltage decreases due to aged deterioration. The disaster prevention light lighting device according to claim 1 or 2, further comprising a disconnection circuit that cuts off the supply of electric power from the charging power source to the constant current circuit at the time of inspection of the disaster prevention light lighting device. The disconnection circuit is a diode in which the power supply circuit is connected to the anode and the constant current circuit is connected to the cathode.
The disaster prevention lamp according to claim 3, wherein the control circuit cuts off the supply of electric power from the charging power supply to the constant current circuit by lowering the voltage of the charging power supply than the battery voltage. Lighting device. The disaster prevention light lighting device according to any one of claims 1 to 4, further comprising a limiter circuit for maintaining the voltage of the charging power supply to be equal to or higher than the first voltage. The disaster prevention light lighting device according to claim 5, wherein the first voltage is the lowest voltage to which electric power is supplied from the charging power source and the control circuit operates. The disaster prevention light lighting device according to any one of claims 1 to 5, wherein the constant current circuit is a resistance. The disaster prevention according to claim 7, wherein when the battery voltage becomes lower than the second voltage in a state where power is supplied from the outside to the power supply circuit, power is supplied from the battery to the control circuit. Light lighting device. The disaster prevention light lighting device according to any one of claims 1 to 8, wherein the control circuit is controlled so that the voltage of the charging power source is higher than the battery voltage by a constant voltage. The disaster prevention light lighting device according to any one of claims 1 to 9,
With the lamp
A disaster prevention light characterized by being equipped with.

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