SU1350734A1 - Apparatus for undervoltage protection of a.c.circuit - Google Patents

Abstract

The invention relates to electrical engineering. The purpose of the invention is to enhance the functionality by providing protection and against overvoltage. By introducing the second semiconductor capacitor 2, which shunts the controlled transition of the first semiconductor switch 1, the device protects the alternating current circuits from both decreasing and increasing the voltage. 1 il. G (L S p I with SL O with

Description

The invention relates to electrical engineering and can be used to protect AC circuits that are critical to voltage changes.

The purpose of the invention is to enhance the functionality by providing protection and against overvoltage.

properties.

The device contains semiconductor switches 1 and 2 in the form of a triac, connected in series with the load

The drawing shows the circuit of the device - IQmention of voltage transition through zero value, due to the fact that capacitor 5 is connected to the control circuit of triac 2 and reaches the value equal to the operation current 3, capacitors 4 and 5, is made of triac 2, the last The semiconductor switches the control transition of the bluetooth keys, and, the resistor 6, Mistor 1, opens them in the control junction, thereby locking the device. The device works as follows,; Capacitor capacitor 5 can be changed again.

When applying a voltage from a source of alternating voltage, the current passing through the control junction is a half-match from the condition of the triac's operation current 2 and the maximum voltage at which it can work

load.

conductor key 1, has a capacitance. For a more reliable bypassing nature and is ahead of the supply control switch of the triac 1 voltage at an angle of 90. When using 25 in series with it, turn on the device in the circuit with an active resistor 6.

load current and voltage on the load 3 coincide in phase and the maximum current through the control junction of the triac 1 will be at that moment when the current through the load passes through a zero value, which allows to ensure the inclusion of the triac 1 with zero control angle with a minimum average value of control current,

When 1 decreases the supply voltage amplitude or it disappears, the current through the triac's switching junction 1 decreases, at the moment of a hundred, no less than the tripping 1 tripping current, the latter closes and the load 3 terminates. The capacitance value of the capacitor 4 is selected so that when the amplitude of the supply voltage decreases to a certain predetermined value, the current through the control junction becomes less than the trigger current of the triac 1.

Editor C, Baker

Compiled by T. Shegolkova

Tehred M. Morgental Proofreader S. Shekmar

Order 5291/52 Circulation 618 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab, 4/5

Production and printing company, Uzhgorod, st. Project, 4

In this case, at nominal voltage and below, the imistor 2 is closed, since the current through the control junction is less than the tripping current of the simulator 2. With an increase in the voltage of the tantrum, the current through the control junction of the triac 2 increases, the amplitude of which will be maximum at the moment the voltage goes over zero, due to the fact that capacitor 5 is turned on in the control circuit of triac 2 and reaches a value equal to triac tripping current 2, the latter will open and back up the control switch of symistor 1, thereby zap ira last,;; capacitance capacitor 5 can

choose from the condition of the triac current 2 and the maximum voltage at which mbzhet work

five

Claims (1)

Invention Formula Device to protect the chain re-. current from undervoltage, 0 containing a semiconductor switch made in the form of a triac, which is connected in series with the load and has a lead for connection to a single power bus, characterized in that, in order to extend the functionality by providing protection and against voltage increase, it is additionally equipped with a resistor, two reactive elements and a second semiconductor switch in the form of a triac, which shunts the control transition of the first semiconductor switch through the resistor, and The elements are included in the control junction circuit of the first and second semiconductor switches, respectively, and have leads for connection to a different power supply. 0 five