JPS5812396Y2 - 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 steps down the power supply voltage with the transformer 22 and rectifies it with the rectifier circuit 23, so that the charging voltage of the capacitor 24 to be charged is superimposed on the voltage of the secondary battery 25. As shown in FIG. 2, the superimposed voltage becomes higher than the battery voltage.

This superimposed voltage a is applied across the dividing resistors 26 and 27, and increases the voltage between the base and emitter of the NPN type first transistor 28.
Forcibly turn on.

When this first transistor 28 is turned on, an NPN type second transistor 28 is turned on.
The transistor 29 is turned off and the display element 30 such as a light emitting diode is momentarily turned off (reset), but in this case,
When the emergency light source 31, 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 voltage between the emitters drops to a point where it is no longer possible to keep the voltage on.

As a result, the first transistor 28 is turned off and the second transistor 29 is turned on, so that the display element 3
0 lights up, and the overdischarge display state occurs 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).

In addition, when the power outage detection contact 21 closes due to a power outage and the emergency light source 31 lights up with the emergency power supply, the above-mentioned phenomenon occurs, and as a result, even though the battery voltage is high, the display A malfunction occurred in which the element 30 turned on and displayed an overdischarge indication, and the overdischarge 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 6 such as an incandescent lamp or fluorescent tube via a power failure detection contact 4 and a rush current detection resistor 5. The other end is connected to the negative side of the secondary battery 3.

Further, a dividing resistor 7.8 is connected to both ends of the secondary battery 30, and one side of a capacitor 9 is connected to the midpoint of this dividing resistor 7.8.

Further, the other end of the capacitor 9 is connected to the negative side of the secondary battery 3.

10 is a PNP whose base is connected to one side of the rush current detection resistor 5, the emitter is connected to the other side of the rush current detection resistor 5, and the collector is connected to the midpoint of the dividing resistor 7°8.
The third transistor of the type, 11, divides the base with a resistor 7.8
A first transistor of NPN type, 14, connected to the midpoint of has its base connected to the collector of the first transistor 11 and to the negative side of the secondary battery 3 via the resistor 15, its emitter connected to the emitter of the first transistor 11, and its collector connected to the display element 16 made of a light emitting diode. and a second NPN transistor connected to the positive side of the secondary battery 3 via a resistor 17.

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 and the rush current detection resistor 5 to start discharging to the emergency lighting light source 6.

At the beginning of discharge, the battery voltage of the secondary battery 3 is high, so
The first transistor 11 is turned on, the second transistor 14 is turned off, and the display element 16 is turned off. However, as time passes, the battery voltage of the secondary battery 3 decreases, and the base voltage of the first transistor 110 decreases. When the emitter voltage reaches a voltage that cannot maintain the on state, the first transistor 1
1 is turned off, and the second transistor 14 is turned on.

This causes the display element 16 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 second transistor 14 is turned on, the emitter voltage of the first transistor 11 (resistor 17 and resistor 120
Since the emitter voltage (determined by the division ratio) is high, in order to turn on the first transistor 11, the base voltage (voltage of resistor 8) is changed to the emitter voltage (voltage of resistor 12).
However, in this case, the resistor 7 and resistor 80 divide the resistance ratio so that the first transistor 11 does not turn on within the range of increase in the battery voltage of the secondary battery 3. The first transistor 11 remains off and the second transistor 14 remains on.
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 6 is energized.

When the emergency light source 60 is turned on, a rush current (large current) B flows as shown in FIG. 4, and the voltage across the dividing resistor 7.8 increases from the battery voltage a to the The voltage drops to a voltage C lower than the off-state voltage of the transistor 11.

As a result, the voltage between the base and emitter of the first transistor 110 becomes a voltage that cannot maintain the on state, but on the other hand, by closing the power failure detection contact 4, the rush current is transmitted to the rush current detection resistor when the emergency lighting light source 6 is turned on. 5, an emitter-base voltage necessary to turn on the third transistor 10 is generated in this resistor 5.

As a result, the third transistor 10 is turned on for the rush current passing time, and the capacitor 9 is charged with a voltage d greater than the base-to-hole voltage e necessary to turn on the first transistor 11.

The charging current of the capacitor 9 is discharged between the base and emitter of the first transistor 110, and the on-voltage between the base and emitter of the transistor 110 is discharged between the base and emitter of the first transistor 110, and the on-voltage between the base and emitter of the transistor 110 is reached by the rush current passing time, that is, the time t3 which is longer than the time from t□ to t2. Since e is applied, the first transistor 11
is turned on, the second transistor 14 is turned off, the display element 16 is turned off, and the display element 16 is reset.

After this reset, the rush current will not flow again even if the power failure detection contact 4 is closed, so the rush current detection resistor 5 has the emitter base required to turn on the third transistor 10. Since no voltage is generated between the capacitors and the third transistor 10 is turned off, no charging current flows to the capacitor 9 and the capacitor 9 is not charged.

Therefore, the base-emitter voltage of the first transistor 110 returns to its normal state.

Furthermore, if the power failure detection contact 4 is opened after being reset, the current to the rush current detection resistor 5 is cut off, so the third transistor 10 is turned off, and as a result, the capacitor 9 is not charged. , first transistor 1
10 The voltage between the base and the plant returns to the normal state.

That is, in either case, 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 16 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.

Furthermore, when the power failure detection contact 4 is closed and the emergency power source is used, when replacing the emergency light source 6 such as an incandescent lamp or fluorescent tube, the display element turns off as before by the above operation. There is no possibility of malfunctions such as lighting up and displaying an overdischarge indication.

FIG. 5 shows the first transistor 1 in the embodiment of FIG.
10 Resistors 7 and 13 formed between the base and the collector
A diode 18 is connected to a closed circuit consisting of a diode 18 which connects a cand to one of the dividing resistors 7 and an anode to the resistor 13.

This diode blocks the charging voltage of the capacitor 9 discharged between the base and emitter of the first transistor 110 from discharging to other circuits at the time of reset, thereby allowing a more stable reset operation.

Furthermore, the capacitor 9 connected between the base of the first transistor 110 and the negative terminal of the secondary battery 3 absorbs high surge voltages that may cause malfunctions.

As described above, according to the present invention, a rush current detection resistor connected between an emergency lighting light source and a power failure detection contact;
A third transistor has a base connected to one of the rush current detection resistors, an emitter connected to the other of the rush current detection resistors, and a collector connected to the midpoint of the divided resistor connected to both ends of the secondary battery. Due to the action of the capacitor connected between the middle point and the other side of the secondary battery, the power failure detection contact closes and the emergency power source turns on the light source for the emergency lights. It is possible to prevent malfunctions in which the display element goes from OFF to ON and displays an overdischarge display again due to the influence of current), and also allows the operation to stop (reset) the overdischarge display to be performed in a stable state. can.

[Brief explanation of drawings]

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 electric 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 electric circuit diagram of a battery checker showing another embodiment of the present invention. It is a diagram. 1.2...Power supply circuit for charging, 3...Secondary battery, 4...Contact for power failure detection, 5...
・Rush current detection resistor, 6... Light source for emergency lights, 7.8... Division resistor L 9... Capacitor, 10.11.14...・Transistor,
12.13.15.17...Resistance, 16...
...Display element, 18...Diode.

Claims (2)

[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, and a rush current detection contact connected between the emergency light source and a power outage detection contact. a third transistor whose base is connected to one of the rush current detection resistors, whose emitter is connected to the other of the rush current detection resistors, and whose collector is connected to the midpoint of the divided resistor; A capacitor is connected between the capacitor and the other battery, the base is connected to the midpoint of the dividing resistor, the emitter is connected to the other side of the secondary battery through the resistor, and the collector is connected to one side of the secondary battery through the resistor. the first transistor, and the first transistor
It is of the same type as the transistor, and its base is connected to the collector of the first transistor and connected to the other side of the secondary battery via a resistor, the emitter is connected to the emitter of the first transistor, and the collector is connected to the display element and the second transistor via the resistor. A battery checker for an emergency light, comprising a second transistor connected to one side of each battery. (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.