JPH0226067Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a voltage detection device for a power outage power supply in an alarm device such as an emergency bell, and is particularly useful for clearly turning on and off an indicator light that detects the voltage of an AC power supply or power supply for a power outage. , it is possible to accurately display the voltage of the power supply for power outage even when the AC power supply is in a power outage.

Below, the example will be explained with reference to the figures.
Tr is a transformer that steps down the AC 100V power supply, and on its secondary side there is a charging path 1 for battery B as a power supply for power outages equipped with a resistor R1 and a diode D1, and a power supply path equipped with a full-wave rectifier Br and a capacitor C1. 2
In addition, the negative terminals of the charging path 1 and the power feeding path 2 provided with the fuse FU are collectively connected back to the transformer via the normally closed contacts NC of the instantaneous return type detection switches T and S.

A diode D2 for blocking reverse current is inserted and connected to the power supply path 2, and a transistor Q is connected between the upstream side of this diode D2 and the battery positive electrode of the charging path 1.
1 and a transistor Q2 is connected between the downstream side and the positive electrode of the battery. A resistor R6, a power source, a voltage indicator LED, and a transistor Q3 are connected in series between the battery positive electrode of the charging path 1 and the load of the power feeding path 2. A diode D3 and a resistor R are connected between the base of the transistor Q2 and the load of the power supply path 2.
8 and transistor Q4 are connected in series. A voltage dividing path 3 consisting of a resistor R2, a variable resistor R3, and a resistor R4 is connected in parallel to the power supply path 2 upstream of the diode D2, and a capacitor C2 is connected in parallel to the resistor R2.

The base of transistor Q4 is connected to the collector of transistor Q3 via resistor R7, and the base of transistor Q3 is connected to the voltage dividing path 3 via variable resistor R3 and the collector of transistor Q4 via feedback resistor R5. are doing.

The base of the transistor Q1 is connected to the normally open contacts N, O of the detection switches T, S via a diode D4 and a resistor R9.

At the latter stage of the power supply path 2, a series circuit of a transistor Q5 and an emergency bell Be serving as an emergency alarm serves as a bell drive circuit, a series circuit of a relay Ry and a transistor Q7 serves as a relay starting circuit, and an emergency bell switch. The indicator lights L at the installation locations are connected in parallel. A resistor R15, a diode D5, and an emergency bell starting switch SW which is locked when closed are connected in series between the base of the transistor Q5 and the base of the transistor Q7. A diode D6 is connected in parallel in the opposite direction to the starting switch SW, and a signal terminal 4 for attaching another starting switch is connected in parallel. A diode D9 is connected in parallel to the relay Ry, and its contact 5
is inserted and connected to the circuit of the transmission terminal 6.

A self-holding circuit is attached to the transistor Q5 in order to continue driving the emergency bell Be even if the switch SW or its circuit is opened for some reason after the start switch SW is closed and locked. In this circuit, a self-holding switch T, a transistor Q6, and a resistor R12 are connected in series to the base of a transistor Q5, and a resistor R10 and a resistor R11 are connected in series between the base of this transistor Q6 and the collector of a transistor Q5.
A capacitor C3 is connected between the base and emitter of. On the other hand, in order to release this self-retention,
The connection midpoint between resistor R10 and resistor R11 connects to the normally open contact NO of detection switches T and S via diode D7.
Also, the base of transistor Q5 is connected to its normally open contact NO through resistor R14 and diode D8.
They are connected to each other. Resistor R14 and diode D8
A simulated resistor R13 of the relay Ry is connected between the connection midpoint of the transistor Q5 and the collector (power supply path 2) of the transistor Q5, and this resistor R13 and the resistor R14 determine the sensitivity of the transistor Q5 as the base resistance of the transistor Q5. The transistor Q5 cannot be turned on unless the resistance between the signal terminals 4 is considerably reduced. This function also includes a resistor R16 between the base and emitter of transistor Q7.

Next, the power supply display and battery B voltage display according to the present invention will be explained. When a commercial 100V power supply is present, the transistor Q3, which receives the base potential from the voltage dividing line 3, turns on and lights up the power supply and voltage indicator LED. Transistors Q1, Q2, Q4 are
In particular, the feedback resistor R5 maintains the base potential of the transistor Q3 high, making it clear that the transistor Q3 is turned on. In the event of a power outage, transistor Q3 is turned off, transistor Q4 is turned on, and the power supply and voltage indicator LED are turned off. During this power outage, the transistor Q2 receives a base current through the transistor Q4 and turns on, and the battery B supplies power to the emergency bell drive circuit and the like in the subsequent stage.

When checking the state of charge of battery B, close the normally open contacts NO of detection switches T and S. When the power supply is present, power is continuously supplied from transistor Q1 while the charge from power supply route 2 remains in voltage dividing route 3, and if the supply voltage of battery B is greater than, for example, 4.8V, transistor Q3 is continuously turned on.
The power and voltage indicator LED will continue to light up to indicate that battery B has sufficient voltage.
Also, when the voltage is below 4.8V, transistor Q3 does not turn on, so the light goes out. When displaying this voltage or when displaying the power supply mentioned above, the base of transistor Q3 is connected to the collector of transistor Q4 via feedback resistor R5, so transistor Q3 is turned on.
and OFF can be made very clear. That is, when used in a linear region, the power supply and voltage indicator LEDs change in brightness, making the display ambiguous, but in this embodiment, it is possible to clearly distinguish whether the lights are on or off. In addition, the specified voltage of 4.8V mentioned above is the variable resistor R.
It is set by adjusting 3.

If transistor Q3 has already been turned OFF due to a power outage and the power and voltage indicator LEDs have gone out, and if you want to check the state of charge while power is being supplied from battery B, the normally open contact NO is closed and transistor Q1 is turned off.
Turn on. In this case, transistors Q2 and Q4
is ON and is supplying power, but the base potential of transistor Q3 is kept low by feedback resistor R5 and is OFF. That is, since the feedback resistor R5 is connected in parallel to the resistors R3 and R4 between the base and emitter of the transistor Q3, the divided voltage (base potential)
is greatly reduced. As a result, when battery B is at the maximum of about 7V, transistor Q3
However, if the charging state is higher than 4.8V but lower than 7V, transistor Q3 can be turned on.
It cannot be turned on and the power and voltage indicator LEDs cannot be turned on. However, this embodiment eliminates the phenomenon such as this hysteresis characteristic. That is, the capacitor C2 connected in parallel to the resistor R2 of the voltage dividing line 3 shorts the resistor R2 of the voltage dividing line 3 when the transistor Q1 is turned on (for checking), and the base potential (divided voltage) of the transistor Q3 temporarily increases. Therefore, if the battery B has a voltage higher than 4.8V, for example about 5V, the transistor Q3 can be turned on, and the power source and voltage indicator LED can be turned on. Of course, since the transistor Q4 is turned off, the transistor Q2 is also turned off, but the transistor Q1 is feeding power instead. In this way, in this embodiment, the voltage of battery B when the power supply and voltage indicator LED lights up, the so-called lighting voltage, can be brought close to the lighting voltage (4.8V), for example 5V, and the state of charge of battery B can be can be checked even during power outage. During this investigation, the detection switches T and S close the normally open contact NO, so the transistor Q5 turns on and drives the emergency bell Be, and the simulated resistor R13 is also supplied with power. Battery voltage can be checked at full load without using the start switch SW.

Next, driving and holding of the emergency bell Be will be explained. When the start switch SW or signal terminal 4 is closed and locked by operation, transistors Q5 and Q7 are turned on, and the emergency bell Be and relay Ry are turned on.
Drive and start. Note that the indicator light L is always lit. By closing the relay contact 5, the appliance connected to the transfer terminal 6 is powered from another power source and used. Since the signal terminal 4 and the starting switch SW may be burnt out in the event of a fire, it is sufficient to close the self-holding switch T. That is, when the transistor Q5 is turned on, the transistor Q6 is turned on in sequence, thereby securing the base current of the transistor Q5. Therefore, transistor Q5
Even if the switch SW etc. is opened afterwards, the emergency bell will be activated.
Continue to drive.

If you want to release the self-holding of such transistor Q5, you can open the self-holding switch T.
This switch T first sets whether or not the emergency bell Be is self-held, that is, it establishes the emergency state of the entire building, and must not be easily opened or closed. Therefore, in this embodiment, when releasing the self-holding, the detection switches T and S are replaced with normally open contacts NO, and the base current of the transistor Q5 is first connected to the resistor R14 and the diode D.
8, the base potential of the transistor Q6 is lowered by the diode D7 to turn it off, and then the switches T and S are returned to the normally open contact NC to cut off the base current of the transistor Q5. At this time, transistor Q6 is turned off until capacitor C3 is charged, and during this time transistor Q6 is turned off until capacitor C3 is charged.
5 turns off. In this way, the detection switches T and S are used both when checking the voltage of battery B and when canceling self-holding.

As described above, the device according to the present invention can display the voltage of the power supply and the power supply for power outage on a single indicator light, and when driving the indicator light with the transistor Q3, the collector potential of the transistor Q4 is fed back.
ON and OFF can be clearly indicated, and the indicator light can be displayed accurately by turning it on and off. When displaying the voltage of the power supply during a power outage, the feedback resistor makes it difficult to turn on transistor Q3, but a capacitor that temporarily provides a high divided voltage to the base of transistor Q3 is installed in the voltage dividing path. It is also possible to accurately detect voltage during power outages.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram of the device of the present invention. 1... Charging path, 2... Power supply path, 3... Voltage division path,
B...Battery, LED...Power supply, voltage indicator,
Be...Emergency bell, C2...Capacitor, R5...
...Feedback resistance, T, S...Detection switch, Q1, Q
2, Q3, Q4...transistor.

Claims (1)

[Scope of utility model registration request] In a device that is equipped with an AC power source and a battery as a power supply for power outages, and the AC power source is provided with a charging path to the battery and a power feeding path to alarms such as emergency bells, power is supplied from the AC power source and the battery. Transistor Q3 is used as an indicator light to display the power and voltage.
are connected in series, and power is supplied from the power supply path to the voltage dividing path that gives a divided voltage to the base of this transistor Q3.When the AC power supply is cut off or the voltage of the battery is checked at the time of a power outage, power is supplied from this battery. A transistor Q4 is connected to the base of a transistor Q2 that connects the battery to the power supply line instead of an AC power supply, the collector of the transistor Q4 is connected to the base of the transistor Q3 via a feedback resistor, and the base of the transistor Q4 is connected to the collector of the transistor Q3. , respectively, and the voltage dividing path is connected to the transistor Q3 when checking the battery voltage.
A voltage detection device for a power supply during a power outage in an emergency alarm device, characterized by having a capacitor that temporarily provides a high partial voltage at the base of the device.