SU1665451A1 - Device for user protection from minimal voltage with time delay - Google Patents

Abstract

The invention relates to electrical engineering and is intended for use in relay protection and automation systems. The purpose of the invention is to simplify and increase reliability by reducing the number of relays and contacts, simplifying setup, and eliminating the possibility of unauthorized re-activation after pressing and releasing the "Stop" button. When the start button 1 is pressed, the voltage is applied to the magnetic starter 6, capacitor 12 and intermediate relay 7. Starter 6 and relay 7 are activated, capacitor 12 is charged through resistor 13 and diode 14. When button 1 is released, magnetic starter 6 and relay 7 held in the on state. When the mains voltage disappears without delay, the magnetic starter 6 is turned off, and the relay 7 is held in the on state by the discharging current of the capacitor 12 flowing through the resistor 13 and the winding of the relay 7. If the mains voltage is restored for a specified period of time, the magnetic starter 6 automatically on, the capacitor 12 is recharged through the resistor 13 and the diode 14. If the network voltage is restored after a period of time greater than the specified one, then the relay 7 after a specified period of time returns to and the similar state and the magnetic starter 6 are not turned on after the mains voltage has been restored. 1 il.

Description

one

(21) 4663504/07

(22) 01/03/89

(46) 07.23.91. Bul

(72) A.L. Zvershanovsky and A.A. Shchabelsky

(53) 621.316.925 (088.8)

(56) USSR Copyright Certificate No. 543077, cl. H 02 H 3/24, 1977.

USSR Author's Certificate No. 943962 Cl. H 02 H 3/24, 1982. (54) DEVICE FOR PROTECTION OF ELECTRICAL CONSUMER AGAINST MINIMUM VOLTAGE WITH TIME EXTRACT

(57) The invention relates to electrical engineering and is intended for use in relay protection and automation systems. The purpose of the invention is to simplify and increase reliability by reducing the number of relays and contacts, simplifying setup and eliminating the possibility of unauthorized re-activation after pressing and releasing the Stop button. When you press the Start button 1, the voltage is applied to the magnetic starter 6, the capacitor

12 and intermediate relay 7. Starter 6 and relay 7 operate, capacitor 12 is charged through resistor 13 and diode 14. When button 1 is released, magnetic starter 6 and relay 7 are held in the on state. When the mains voltage disappears without delay, the magnetic starter 6 is turned off, and the relay 7 is held in the on state by the discharge current of the capacitor 12 flowing through the resistor

13 and the winding of the relay 7. If the mains voltage recovers within a predetermined period of time, the magnetic starter 6 automatically turns on, the capacitor 12 is charged through the resistor 13 and the diode 14. If the mains voltage recovers after a period exceeding the specified one, then the relay 7 after the expiration a predetermined period of time returns to the initial state and the magnetic starter 6 does not turn on after the restoration of the mains voltage. 1 il.

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The invention relates to electrical engineering and is intended for use in relay protection and automation systems.

The purpose of the invention is to simplify and increase reliability by reducing the number of relays and contacts, simplifying setup and eliminating the possibility of unauthorized re-activation after pressing and releasing the Stop button.

The drawing shows a diagram of the device.

The device to protect the consumer from the minimum voltage with time delay contains the Start button 1 with the first closing contact 2, the Stop button 3 with the first normally closed contact

4 and the second pin 5, magnetic starter 6, intermediate relay 7 with the first closing contact 8, the first 9 and second 10 input terminals for connection to the terminals of the monitored mains voltage, and the chain of the series 1 connecting contact 2 of the Start 1 button shunted by the first closing contact 8 intermediate relay 7, first break contact 4 buttons Stop 3 and a magnetic starter 6 coil are connected between the first 9 and second 10 input pins.

The device has a rectifying bridge 1.1, a capacitor 12, a trimming resistor 13, a diode 14, with the Start button

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1 is equipped with a second closing contact 15, the intermediate relay 7 is equipped with a second closing contact 16, and the second contact 5 of the Stop button 3 is made as a break contact. The rectifier input of the bridge bridge 11 is connected in parallel to the coil of the magnetic actuator 6. Between the output terminals of the rectifier bridge 11, the first chain is connected in parallel, consisting of 10 connected capacitors 12 in series and a trimming resistor 13 of the shunt diode 14, whose cathode is connected with a negative output pin of the rectifying bridge 11, and the second chain consisting of 15 serially connected windings of the intermediate relay 7, the second contact 5 of the Stop 1 button and the second closing contact 15 of the Start 1 button, shunt the second closing 20 pin 16 intermediate relay 7.

The device works as follows.

When the Start button 1 is pressed, contact 2 is closed and the voltage is applied to the coil of the magnetic starter 6 and the input of the rectifier bridge 11, the capacitor 12 is charged through the resistor 13 and the diode 14, the contact 15 of the Start button 1 is closed and through the intermediate relay 7 coil 30 current flows. In this case, the intermediate relay 7 is activated and by its closing contacts 8 and 16 bypins the contacts 2 and 15 of the Start 1 button. Further, when the Start button 1 is released, the intermediate relay 7 and 35 magnetic starter 6 is held in the on state.

When the mains voltage disappears without delay, the magnetic starter 6 is turned off, the voltage at the output of the direct bridge 11 disappears, but the intermediate relay 7 is kept in the on state by the discharge current of the capacitor 12 flowing through the circuit of the negative capacitor 12, the trimmer - 45 the resistor 13, the closed contact 16 of the intermediate relay 7, the closed contact 5 of the Stop 3 button, the coil of the intermediate relay 7, the positive plate of the capacitor 12. The magnitude of the discharge current, and hence the holding time of the intermediate In the on state, the relay 7 is determined by the resistance value of the trimming resistor 13. If the mains voltage recovers within a predetermined period of time when the current flowing through the winding of the intermediate relay 7 exceeds the release current of this relay, the magnetic starter 6 automatically turns on and capacitor

12 is discharged through the resistor 13 and the diode 14, since the contacts 8 and 16 of the relay 7 remain closed for a given time delay.

If the network voltage is restored after a period of time greater than the set one, the current flowing through the coil of the relay 7 is reduced to the magnitude of the release current, contacts 8 and 16 open, and the magnetic starter 6 does not turn on.

Thus, when successive short-term power disappears in the network within a predetermined period of time, the magnetic starter 6 automatically switches on.

When the Stop button 3 is pressed, the power supply circuits of the magnetic actuator 6 and the intermediate relay 7 are broken, contacts 8 and 16 are opened. In this case, the device is disconnected regardless of whether there is or is no power supply at the moment when the Stop 3 button is pressed.

The advantages of this device are: the exclusion of the possibility of unintended switching on the magnetic starter, a small number of intermediate relays, the absence of a time relay, as well as ease of setup.

The invention makes it possible to increase the reliability of the device, to expand the field of application of automatic backup of electrical installations in all areas of the national economy.

Claims (1)

Invention Formula The device to protect the consumer from the minimum voltage with time delay, containing the Start button with the first closing contact, the Stop button with the first opening contact and the second contact, the magnetic starter, the intermediate relay with the first closing contact, the first and second input terminals for connecting to the terminals of the monitored network voltage, and the chain of serially connected closing contact of the Start button, shunted by the first closing contact of the intermediate relay, the first opening contact The stop button cycle and the magnetic starter coil is connected between the first and second input pins, characterized in that, in order to simplify and increase reliability by reducing the number of relays and contacts, simplifying setup and eliminating the possibility of unauthorized re-activation after pressing and releasing the Stop button, into it a rectifying bridge, a capacitor, a tuned resistor, a diode, a start button equipped with a second closing contact, an intermediate relay equipped with a second closing contact, and a second contact kN Folders stop is designed as a break contact, the input bridge rectifying unit connected in parallel with the coil of the magnetic actuator, and between the output terminals of the bridge parallel to the rectifying unit includes a first chain consisting of the following connected capacitor and tuned resistor, shunted by a diode, the cathode of which is connected to the negative output terminal of the rectifying bridge, and the second chain consisting of the intermediate relay winding, the second contact of the Stop button and the second closing contact of the Start button, shunted by the second closing contact of the intermediate relay .