SU1228257A1 - A.c.switch - Google Patents

Abstract

The invention can be used in electronic and electrical equipment for the non-contact switching of the mains voltage of the industrial frequency. The purpose of the invention is to reduce the distortion of the shape of the switched voltage at the output and reduce the level of radiated noise. The device contains a switching voltage source 1, a load 2, diodes 3-6, a bridge, thyristor 7, zener diode 8, resistors 9 and 11, a capacitor 10, a photodetector (photo thyristor) 12 optocoupler, a light emitter (LED) 13, source 14 a control signal and a limiting resistor 15. Connecting the second output of the parallel RC circuit to the connection point of the switching voltage source 1 with the load allows the thyristor to be kept open by the discharge current of the capacitor at zero switching voltage. 1 il. i (About tc to 00 to eat

Description

The invention relates to a pulse technique, and can be used in electronic and electrical equipment for contactless switching of a mains voltage of an industrial frequency.

The purpose of the invention is to reduce the distortion of the shape of the switched voltage at the output and to reduce the level of radiated interference by keeping the thyristor in the open state by the discharge current of the capacitor at zero values of the switching voltage.

The drawing shows a circuit diagram of the device.

The device contains a source of 1 kom1-1utirovogo voltage, connected in series with the load 2 in the diagonal of the alternating current of the bridge of diodes 3-6, in the diagonal of the direct current of which the thyristor 7 is connected. connected to the first parallel parallel circuit from a capacitor 10 and a resistor 11, the second pin of which is connected to the connection point of source 1 with load 2. Between the cathode of the Zener diode 8 and the control electrode thyristor 7 is turned on a photodetector (phototiris torus) 12 of the optocoupler, the light emitter (LED) 13 of which is connected to the output of the control signal source 14 In series with the photo thyristor 12, the limiting resistor 15 is turned on

The device works as follows.

In the operating mode, the thyristor 7 is opened at the beginning of the half-cycle of the switching voltage of the control current pulses along the circuit: source 1 - capacitor 10 - resistor 9 - photo thyristor 12 - diode 5 - source. At the beginning of another half-period, com Editor M.Tovtin Order 2296/57

Compiled by M. Shchedrin

Tehred I. Veres Proofreader T, Kolb

Circulation 816 Subscription

VNIIGSH State, USSR Committee

for inventions and discoveries 113035 ,, Moscow, Zh-35, Raushsk nab., d. 4/5

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

of the mutable voltage, the thyristor is maintained by an open-capacitive reactive current flowing through the ro circuit: source - 1 - diode A - thyristor 7 zener diode B - resistor 9 - charge female capacitor 10 - source 1. This current is out of phase relative to the active load current 90 ° and exceeds (together with the active

component of the load current) the desired value of the thyristor holding current 7.

In standby mode, the help of the photo thyristor 12 is aborted.

control pulses on the thyristor 7 and the latter is closed.

In the operating mode, the photo thyristor 12 is opened by the arrival of a pulse of light from the LED 13, which is excited by a control signal from the source 14.

Claims (1)

Invention Formula An alternating current key containing a diode bridge, the diagonal of an alternating current of which is connected in series with a switching voltage source and load, and the diagonal of a direct current is connected to a thyristor parallel to the RC circuit, the first output of which is connected via a resistor to the zener diode whose anode is connected with a thyristor cathode, and an optocoupler, the photodetector of which is connected between the cathode of the Zener diode and the control electrode of the thyristor, and the light emitter of the optocoupler is connected to the output of the control signal source, differing and u and in that, to reduce the distortion of shapes of dial voltage at the output and reduce the level of radiated noise vtod second parallel RC-circuit is connected to point of connection of the source of the switched voltage with the load.