JPS5817359Y2 - Emergency light battery checker - Google Patents

Description

[Detailed description of the invention] This invention indicates that when the voltage of a secondary battery, which serves as an emergency power source for emergency lights, guide lights, etc., falls below a certain specified voltage, the over-discharge is indicated, and the battery is recharged by charging etc. This is a battery checker for emergency lights that maintains an over-discharge indication even when the voltage increases, and is affected by the rush current (large current) that flows for a certain period of time when light sources for emergency lights such as incandescent lamps and fluorescent tubes are turned on. To provide a battery checker for an emergency light that can perform an operation of stopping (resetting) an overdischarge display in a stable state without causing any problems.

A conventional battery checker of this type had a circuit configuration as shown in FIG.

And the stoppage of overdischarge display in this conventional circuit configuration (
The reset) operation was performed by closing the power failure detection contact.

That is, when the power failure detection contact 21 is closed, the charging power supply circuit lowers the power supply voltage with the transistor 22 and rectifies it with the rectifier circuit 23, and the charging voltage of the capacitor 24 to be charged is rectified with the secondary battery rectifier circuit 23. Due to the charging power supply circuit, the charging voltage of the capacitor 24 being charged is superimposed on the voltage of the secondary battery 25, resulting in a superimposed voltage higher than the battery voltage, as shown in FIG.

This superimposed voltage a is applied to both ends of the divided resistors 26 and 27, increasing the base-to-edge voltage of the first NPN transistor 28, and forcing the first transistor 28 to turn on.

When this first transistor 28 is turned on, a PNP type second transistor 28 is turned on.
As the transistor 29 turns on, the PNP type third
The transistor 30 is turned off and the display element 31 such as a light emitting diode is momentarily turned off (reset), but in this case,
When the emergency light source 32 such as an incandescent lamp or a fluorescent tube is turned on, as shown in FIG.
2, the rush current (large current) A flows, and the voltage across the dividing resistors 26 and 27 becomes a voltage d lower than the off-voltage C of the first transistor 28 shown in FIG.・The emitter voltage drops to a voltage that cannot maintain the on-voltage.

As a result, the first transistor 30 is turned on, and as a result, the display element 31 lights up and enters the overdischarge display state again.

In this case, the voltage of the secondary battery 25 rises above the specified voltage after the rush current (large current) passes, but in the conventional circuit configuration, even though the secondary battery 25 is not over-discharged, As mentioned above, the battery checker malfunctioned by displaying an overdischarge display, and the overdischarge display could not be stopped (reset).

Furthermore, when the power outage detection contact 21 closes due to a power outage and the emergency light source 32 is turned on by the emergency power supply, the above-mentioned phenomenon occurs, and as a result, even though the battery voltage is high, the display element 31 turned on to display an over-discharge indication, and the over-discharge indication could not be stopped (reset).

The present invention has been devised to solve the above-mentioned conventional problems, and the present invention will be explained below based on drawings showing embodiments thereof.

In Figure 3, 1 is a transformer that steps down the power supply voltage.
The alternating current voltage appearing on the secondary side of the transformer 1 is rectified by a rectifier circuit 2, and the secondary battery 3 is constantly charged.

The positive side of the secondary battery 3 is connected to one side of an emergency light source 5 such as an incandescent lamp or a fluorescent tube via a power failure detection contact 4.
The other end of the emergency light source 5 is connected to the negative side of the secondary battery 3.

Furthermore, the positive side of this secondary battery 3 is connected to a power failure detection contact 4.
The other end of the capacitor 6 is connected to one end of a resistor 7, and the other end of the resistor 7 is connected to the negative side of the secondary battery 3.

Furthermore, dividing resistors 8 and 9 are connected to both ends of the secondary battery 3.

10 has an anode connected to the midpoint of the series circuit made up of the capacitor 6 and resistor 7, and a cathode connected to a dividing resistor 8.
．． The diode 11 has its base connected to the midpoint of dividing resistors 8 and 9, its emitter connected to the negative side of the secondary battery 3 via resistor 12, and its collector connected to the midpoint of resistor 1.
The first NPN transistor 14 is connected to the positive side of the secondary battery 3 via 3, and the base is connected to the first transistor 1.
1, the emitter is connected to the positive side of the secondary battery 3 through a resistor 15, and the collector is connected to the negative side of the secondary battery 3 through a resistor 16.
The transistor 17 is a PNP whose base is connected to the collector of the second transistor 14, whose emitter is connected to the emitter of the second transistor 14 via a display element 18 made of a light emitting diode, and whose collector is connected to the emitter of the first transistor 11. This is the third transistor of the type.

To explain the operation of the above circuit configuration, when the power is on, the battery voltage of the secondary battery 3 is high due to charging, but when a power outage occurs, the power outage detection contact 4 closes and the secondary battery 3 is connected to the power outage detection contact. 4 to the emergency lighting light source 5.

At the beginning of discharge, the battery voltage of the secondary battery 3 is high, so
The first transistor 11 and the second transistor 14 are turned on, and the third transistor 17 is turned off, and the display element 18 is turned off. However, as time passes, the secondary battery 3
When the battery voltage of the first transistor 11 drops and the voltage between the base and emitter of the first transistor 11 becomes such that it cannot remain on, the first transistor 11 turns off, and as a result, the second
The transistor 14 is turned off and the third transistor 17 is turned on.

This causes the display element 18 to light up, indicating an overdischarge state.

When electricity is started in this state, the battery voltage of the secondary battery 3 increases due to charging.

In this case, when the third transistor 17 is turned on, the emitter voltage of the first transistor 11 (the emitter voltage determined by the division ratio of the resistor 15 and the resistor 12) is high. voltage (voltage of resistor 9) to emitter voltage (voltage of resistor 12)
However, in this case, the divided resistance ratio of the resistor 8 and the resistor 9 is set so that the first transistor 11 is not turned on within the battery voltage increase range of the secondary battery 3, so the first transistor 11 The transistor 11 and the second transistor 14 continue to be off, and the third transistor 17 continues to be on, and as a result, the overdischarge display state continues.

Next, in order to stop (reset) this overdischarge display, when the power failure detection contact 4 is closed, the emergency light source 5 is energized.

When the emergency lighting light source 5 is turned on, a rush current (large current) B flows as shown in FIG. 4, and the voltage across the dividing resistors 8 and 9 varies from battery voltage a to The voltage drops to a voltage C lower than the off-voltage of the transistor 11.

As a result, the voltage between the base and emitter of the first transistor 11 becomes such that it cannot maintain the on state, but on the other hand, by closing the power failure detection rear point 4, the power failure detection contact 4 is connected from the positive side of the secondary battery 3. A current flows through the series circuit consisting of the capacitor 6 and the resistor 7, and a voltage d higher than the base-emitter voltage e required to turn on the first transistor 11 is generated in the resistor 7, and that voltage is applied to the diode 10. The on-voltage e is applied between the base and emitter of the first transistor 11 through the inverter, and the on-voltage e is applied between the base and emitter of the first transistor 11 until the rush current passing time, that is, the time t3 which is longer than the time from ti to t2. Therefore, the first transistor 11 is turned on, and as a result, the second transistor 14 is turned on and the third transistor 17 is turned off, so that the display element 18 is turned off and reset.

After this reset, even if the power failure detection contact 4 is closed, the capacitor 6 is charged, so no charging current flows from the secondary battery 3, and as a result, no voltage is generated across the resistor 7. First, the base-emitter voltage of the first transistor 11 returns to its normal state.

In addition, when the power failure detection contact 4 is opened, the capacitor 6
The charging voltage is discharged into the closed circuit consisting of the resistor 7 and the emergency light source 5, and the state returns to the state for the next reset.

This also applies to emergency operations when the power failure detection contact 4 closes when the battery voltage is high and the display element 18 is off.
The above operation does not cause a malfunction in which the display element turns on from off to display an overdischarge display as in the conventional case.

Here, the diode 10 blocks the current flowing from the secondary battery 3 to the resistor 7, and prevents the operating point of the first transistor 11 from changing.

Further, a capacitor 19 connected between the base of the second transistor 14 and the base of the third transistor 17 absorbs high surge voltages that cause malfunctions.

FIG. 5 shows the first transistor 1 in the embodiment of FIG.
Resistors 8 and 13 formed between the base and collector of 1
A diode 20 is connected to a closed circuit consisting of the following: the cathode of the diode 20 is connected to one of the divided resistors 8, and the cathode is connected to the resistor 13.

The diode 20 blocks the voltage of the resistor 7 applied between the base and emitter of the first transistor 11 from flowing into other circuits at the time of reset, thereby making the reset operation more stable.

Furthermore, in FIG. 5, the display element 18 is connected between the collector of the third transistor 17 and the emitter of the first transistor 11, and in this circuit, the display element 18 is connected between the collector of the third transistor 17 and the emitter of the first transistor 11. Since the third transistor 17 is connected to the side, the emitter potential of the first transistor 11 when the third transistor 17 is on can be increased compared to the circuit shown in FIG. Can be used in saturated conditions down to low ranges.

As described above, according to the present invention, when the power failure detection contact closes and the emergency light source is turned on by the emergency power source, the display element changes from OFF to ON due to the influence of the rush current (large current) that flows for a certain period of time. There is no possibility of a malfunction in which the overdischarge display is performed again, and the operation for stopping (resetting) the overdischarge display can be performed in a stable state.

[Brief explanation of the drawing]

Figure 1 is an electric circuit diagram of a conventional battery checker, Figure 2 is an explanatory diagram of the reset operation of the same battery checker,
Fig. 3 is an electrical circuit diagram of a battery checker showing one embodiment of the present invention, Fig. 4 is an explanatory diagram of the reset operation of the same battery checker, and Fig. 5 is an electrical circuit diagram of a battery checker showing another embodiment of the present invention. It is a circuit diagram. 1, 2...Power supply circuit for charging, 3...Secondary battery, 4...Contact for power failure detection, 5...
・Light source for emergency lights, 6... Capacitor, 7...
...Resistance, 8,9...Divided resistance, 10...
...Diode, 11,14.17...Transistor, 12.13,15゜16...Resistor,
18... Display element, 19... Capacitor, 20... Diode.

Claims (4)

[Scope of utility model registration request] (1) A charging power supply circuit that charges the secondary battery, a battery checker that is connected to the secondary battery and that detects the battery voltage and displays the required display, and a battery checker that connects the secondary battery to the secondary battery via a power outage detection contact. The battery checker includes a divided resistor connected to both ends of a secondary battery, one end of which is connected between the emergency light source and a power outage detection contact, and the other end of which is connected to the emergency light source and a power outage detection contact. A series circuit consisting of a capacitor and a resistor whose ends are connected to the other side of the secondary battery, a diode connected between the midpoint of this series circuit and the midpoint of the dividing resistor, and a base connected to the midpoint of the dividing resistor. A first transistor having an emitter connected to the other side of the secondary battery through a resistor and a collector connected to one side of the secondary battery through a resistor, which is a different type from this first transistor, and whose base is connected to the first transistor. A second transistor is connected to the collector of the transistor, the emitter is connected to one side of the secondary battery via a resistor, and the collector is connected to the other side of the secondary battery via a resistor, and the base is connected to the second transistor. Connect the emitter to the collector of the second transistor through the display element.
A battery checker for an emergency light, comprising an emitter of a transistor and a third transistor whose collector is connected to the emitter of the first transistor. (2) The emergency light battery checker according to claim 1, wherein a diode is connected to a closed circuit formed between the base and collector of the first transistor. (3) The battery checker for emergency lights according to claim 1, which is a registered utility model and comprises a capacitor connected between the base of the second transistor and the base of the third transistor. (4) The emergency light battery checker according to claim 1, wherein the display element is connected between the collector of the third transistor and the emitter of the first transistor.