SU794556A1 - Voltage monitoring device - Google Patents

Description

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The invention relates to an electrical measuring technique and can be used to monitor a single-phase voltage.

Devices are known that contain light signaling devices according to the number of phases of a controlled three-phase voltage 1.

A disadvantage of the known devices lies in their limited functionality, since they do not provide an audible signal of voltage disappearance and do not memorize short-term voltage drops.

It is also known a voltage control device comprising a rectifying bridge, resistors, capacitors and a separation diode 2}.

A disadvantage of the known device is its limited functionality.

The purpose of the invention is to expand the functionality.

This is achieved by the fact that in a known device containing a rectifying bridge, one of the diagonals of which includes a source of controlled voltage, capacitors, resistors, the first diode, one of the corners of the rectifying bridge is connected to the first lining of the first capacitor and the anode of the first diode, the cathode which is connected to the first plate of the second capacitor and the first output of the first resistor, a buzzer, first and second thyristors, a second and third diodes and a control button with opening and closing coders are entered contacts, the corresponding vertex of the rectifying bridge being connected through the serially connected closing contact of the control button and the second resistor to

control electrode of the first thyristor, the anode of which is connected to the second output of the first resistor and the anode of the second diode, the cathode of which is connected to the control electrode of the second thyristor, anode

through the disconnected contact of the control button and the buzzer is connected to the cathode of the first diode, the cathode of the second thyristor is connected to the second plate of the second capacitor and the anode of the third diode, the cathode of which is connected to the cathode of the first capacitor and the corresponding rectifier bridge.

The drawing shows a schematic diagram of the device.

The device contains a rectifying bridge 1, capacitors 2 and 3, diodes 4-6, a control button 7 with an opening contact 8 and a closing contact 9, thyristors 10 and 11, resistors 12 and 13, an audible alarm 14 and input terminals 15 and 16.

The device works as follows.

The supply voltage of the monitored voltage to the input terminals 15, 16 of the device is positive potential from the rectifying bridge 1 through diode 5, resistor 12, diode 6 to the control electrode of the thyristor 10, which opens and connects the buzzer 14 through diodes 4, 5 to the rectifier to the swine bridge 1.

The disconnection of the signaling device 14 is made by briefly pressing the button 7. At the same time, the disconnecting contact 8 breaks the power supply circuit of the thyristor 10, which turns off the warning device 14, and through the closing contact 9 of the button 7 and the resistor 13 turns on the thyristor 11, which blocks the diode 6 by negative voltage, thereby disconnecting thyristor control electrode 10 against a positive potential.

Since the thyristors 10 and 11 are powered from bridge 1 by a pulsating voltage, a capacitor 2 is used to smooth the voltage pulsations, which feeds the thyristor 11 between the pulses when the voltage becomes zero.

When the monitored voltage disappears, capacitor 2 is discharged through thyristor 11, which disconnects and unlocks diode 6. At the same time, the positive potential from capacitor 3 through resistor 2 and diode 6 opens thyristor 10, which connects signaling device 14 to capacitor 3. Duration of signaling device 14 at the continuous absence of voltage is determined by the capacitance of the capacitor 3 and the resistance of the detector 14.

The device signals both a short-term voltage drop (one, two times), and a long absence of voltage. This is achieved by selecting the capacitance of the capacitor 2, which, when the monitored voltage disappears, keeps the thyristor 11 in the on state and blocks the diode 6 with a negative voltage for a certain time, depending on the constant discharge time of the capacitor 2.

If the time of disappearance of the monitored voltage is longer than the constant time of the discharge of the capacitor 3, then after its discharge at the time of the occurrence of the monitored voltage, the capacitor 3 is charged and the thyristor 10 is turned on again.

If the time of disappearance of the monitored voltage is shorter than the time constant of the discharge of capacitor 3, then when the thyristor 10 is turned on during this time interval, the analyzer 14 operates from the capacitor 3, which leads to its partial discharge. When a monitored voltage is applied, a capacitor 3 is charged and the detector 14 continues to operate from bridge 1 until button 7 is pressed. Thus, the device, due to the capacitor 3 capacity, allows a certain time, depending on the constant discharge time of the capacitor 3, to signal long disconnected controlled voltage. When a controlled voltage appears, even if the capacitor 3 during the pause, the warning lamp 14 is fully de-energized, is re-activated. Depending on the choice of the capacitance of the capacitor 2, the device reacts either to the short-term disappearance of the monitored voltage (one, two half-periods) or to its long absence (from one period to several seconds).

Claims (2)

1. USSR author's certificate number 479192, cl. H 02 H 3/24, 1973. 2. USSR author's certificate number 565345, cl. H 02 H 3/24, 1972 (prototype). J6 s.