JPH01278221A - Voltage monitoring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a voltage monitoring device for monitoring the voltage of a commercial power source and protecting connected equipment from voltage fluctuations.

[Prior Art] Conventionally, there have been devices not shown in FIG. 2 as devices for stabilizing voltage fluctuations in a commercial power source and protecting connected devices. In Figure 2, (1) is A V R (au
tomatic voltage regulation
or), (2> indicates the connected equipment. As shown in Figure 2, in places where the commercial power supply voltage fluctuates frequently, do not supply power directly to the equipment (2) from the commercial power supply. After stabilizing the voltage via an AVR (automatic voltage regulator), power is supplied to the device (2) to protect the device (2) and drive it normally.

[Problem to be solved by the invention] In the conventional device as described above, commercial power is always supplied to the AVR and the equipment, so it is possible to supply stable power against normal voltage fluctuations. However, there is a problem in that if a voltage fluctuation exceeding a permissible range occurs, there is a risk that the connected AVR or equipment (hereinafter referred to as equipment) may be destroyed.

This invention was made to solve this problem, and it monitors the voltage value of the commercial power supply to supply stable power against voltage fluctuations, and to prevent voltage fluctuations exceeding the permissible range from occurring. However, the aim is to obtain a voltage monitoring device that will not destroy connected equipment.

[Means for Solving the Problems] A voltage monitoring device according to the present invention includes a high voltage monitoring device that monitors the high voltage range of a commercial power supply, a low voltage monitoring device that monitors the low voltage range, and a voltage monitoring device that monitors the high voltage range of a commercial power source. It is equipped with a timer that measures a predetermined time from
We decided to connect or disconnect the power supply to VR.

[Function] The present invention includes a high voltage monitoring device that monitors the high voltage range of a commercial power supply, a low voltage monitoring device that monitors the low voltage range, and a timer that measures a predetermined time after the power is turned on. In preparation, we decided to connect or cut off the power supply to the AVR according to commands from each of these devices, so the AVH
Connected equipment can be protected even in the event of abnormal voltage fluctuations that exceed the allowable range and cannot be stabilized.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 2 indicate the same or corresponding parts, and (
3) is a rectifier, (4) is a resistor, (5) is a Zener diode, (6) is a high voltage monitoring device, (7) is a low voltage monitoring device, (8) is a timer, (9) is an AND gate, ( 10) is a relay circuit, (10a) and (10b) are relay contacts, (11), (12), (13), (1
4) is a resistor, (15) is a gate transistor,
(16) is a relay circuit.

Next, the operation will be explained. The commercial power supply is converted to direct current by a rectifier (3), and the voltage is divided by a resistor (4) and made into a constant voltage by a Zener diode (5), which is then connected to a high voltage monitoring device (6) and a low voltage monitoring device (7). .

Timer (8), AND gate (9), relay circuit (1o
) etc. On the other hand, the output from the flow path device (3) is input to the high voltage monitoring device (6) as a voltage divided by the resistors (11) and (12).

This high voltage monitoring device (6) monitors the high voltage value of the commercial power supply, and the voltage value is within a predetermined normal high voltage range (A
If the voltage is within the range that can be stabilized by V R (1) (for example, +20% of the commercial power supply voltage value), a logic "1" is output to the AND gate (9), and the voltage exceeds the normal high voltage value. If so, the logic “0” (ie, output is stopped) is output to the AND gate (9).

On the other hand, the output from the rectifier (3) is also a resistor (13).

Low voltage monitoring device (7) as voltage divided by (14)
is input.

This low voltage monitoring device (7) monitors the low voltage value of the commercial power supply, and the voltage value is within a predetermined normal low voltage range (
If the voltage is within the range that can be stabilized by the AVR (1) (for example, -20% of the commercial power supply voltage), a logic "1" is output to the AND gate (9), indicating a normal low voltage value. If the value is less than 0, a logic "0" (ie, output is stopped) is output to the AND gate (9).

On the other hand, the timer (8) remains constant (
T) Outputs logic r□ until time elapses, and outputs logic "1" to AND gate (9) after a certain time elapses.

The AND gate (9) is connected to the gate of the gate transistor (15) and provides an output to the gate transistor (15) when all inputs are logic "1".

When there is an output from the AND gate (15), the relay circuit (10) is energized, operating the relay contact (10a),
The relay circuit (16) is energized, operating the relay contact (10b), and the commercial power supply is connected to the equipment (
2).

That is, in this invention, if the voltage fluctuation of the commercial power supply is within a range that does not damage the connected equipment (
In this example, ±15%) is regarded as a normal voltage, and if the voltage is higher than this, the output from the high voltage monitoring device (6) is set to logic "0", and the gate transistor (15%) is regarded as a normal voltage.
) to cut off the commercial power input to the AVR, (1), and if the voltage value drops below the predetermined normal voltage, the output from the low voltage monitoring device <7) is set to logic "
0", the gate transistor (15) is turned off and the commercial power input to the AVR (1) is cut off to protect the equipment (2), and the voltage value of the commercial power supply has returned to normal. In this case, the relays (10) and (16) are operated to input commercial power to the AVR (1) again.

In addition, the timer (8) sets the output to the AND gate (9) to logic "0" until a predetermined (T) time elapses after commercial power is applied to this device, and then turns off the power and then turns the power back on. If the transient voltage of the commercial power supply immediately after recovery is A
This prevents the liquid from flowing into the VR (1) and equipment (2) and damaging the equipment.

[Effects of the Invention] As described above, the present invention includes a high voltage monitoring device that monitors the high voltage range of a commercial power supply, a low voltage monitoring device that monitors the low voltage range, and Equipped with a timer to measure the AV
Since we decided to connect or cut off the power supply to R, even if abnormal voltage fluctuations exceeding the allowable range that cannot be stabilized by AVR occur, the connected equipment will be destroyed. This has the effect of being suitable for driving equipment in an unattended state.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional device. (1) is the AVRl (2) is the equipment, (3) is the rectifier, (4
) is a resistor, (5) is a Zener diode, (6) is a high voltage monitoring device, (7) is a low voltage monitoring device, (8) is a timer,
(9) is an AND gate, (10) is a relay circuit, (10
a) and (10b) are respectively relay contacts, (11)
, (12). (13) and (14) are resistors, (15) are transistors, and (16) are relay circuits. In addition, the same symbols in each figure indicate the same parts. Jōsen Figure 1 Procedural Amendment (Voluntary) August 26, 1988

Claims (1)

[Claims] A relay circuit having a relay contact that connects and disconnects between a commercial power source and an AVR (automatic voltage regulator); A high voltage monitoring device that inverts the output logic when a voltage value is detected, and a low voltage monitoring device that monitors the low voltage range of the commercial power source and inverts the output logic when a low voltage value below a predetermined low voltage value is detected. A voltage monitoring device, a timer that inverts the output logic when a predetermined time has elapsed after the power is turned on to the device, and each output of the high voltage monitoring device, low voltage monitoring device, and timer all has a logic “ 1, the voltage is output to the relay circuit to connect the relay contact, and an AND gate that cuts off the relay contact when the logic of any of the outputs is reversed. monitoring equipment.