SU1275757A1 - Optronic selector switch - Google Patents

Abstract

The invention relates to contactless switching technology of alternating current circuits and can be used in automation, in particular in digital systems of pulse-phase control of thyristor converters. The purpose of the invention is to expand the functional capabilities and increase noise immunity. For CO 1 cl vl) SP s

Description

A first transistor optocoupler 1 is inserted into the device; its LED is connected to a source of control signals, and the collector circuit of the composite phototransistor is connected to the first input of the NAND 7 element, the second transistor optocoupler 2, which LED through the current limiting resistor and bridge 8 connected to a source of alternating voltage as well. composite transistor emitter circuit - with RS75757 S-input

trigger 3j, the R input of which is connected via a variable resistor 5 to a constant voltage source and through a capacitor 4 to the Q output of the RS trigger and the input of inverter 6, the output of which is connected to the second input of the NAND element. The drawing shows two thyristor optocouplers 9, a connection circuit through an electronic amplifier circuit with an output of the NAND element, with a load ZH and a source of alternating voltage. 2 Il.

The invention relates to contactless switching technology of alternating current circuits and can be used in automation, in particular in digital systems of pulse-phase control of thyristor converters.

The purpose of the invention is to enhance the functionality and increase noise immunity.

FIG. 1 is a diagram of the switch; in fig. 2 - time diagrams, according to his work.

The switch contains transistor optocouplers 1 and 2, RS-flip-flop 3, the input of which is connected to the output of transistor 2, and a Q-input through a capacitor 4 is connected to the R-input of the trigger and resistor 5, the inverter 6, the input of which is connected to the Q-output RS- trigger 3, and the output - with the input of the element AND-HE 7, the second input of which is connected to the output of the input transistor optocoupler 1, the bridge rectifier 8, the output of which is fed to the input of the transistor optocoupler 2, the output of the element AND-HE 7 through the emitter follower connected with a common emitter input transistor switch, thyristor optro Connect to the input of new 9.

The device works as follows.

The network voltage 10 (Fig. 2) goes to the bridge terminal 8, at the output of which the voltage is converted to a pulsating frequency doubled relative to the network (11,

FIG. 2). This pulsating voltage is applied to the input LED of the transistor optocoupler 2, from the output of which the trapezoidal pulses 12 are removed (Fig. 2), which are fed to the S input of the RS flip-flop 3.

RS-Trigger 3 converts the input voltage to. rectangular pulses 13 (Fig. 2). Inverter 8 inverts square pulses, but at the expense of a circuit consisting of a capacitor 4 and a variable resistor 5, the trailing edge of the inverted pulses 14 (Fig. 2) can be controlled during a half-period, which allows The signal from the input transistor optocoupler 1 receives a signal to turn on the thyristor optocouplers 9 at a certain moment relative to zero of the mains voltage. Transistor optocouplers 1 and 2 and thyristor optocouplers 9 are used for the galvanic isolation of input and output power circuits.

Thus, the optoelectronic switch ensures that the load is switched on not only when the mains voltage passes through the zero state, but also during the half-period when it is allowed by an inductive load.

Claims (1)

Invention Formula An optoelectronic switch containing two thyristor optocouplers, the LEDs of which are connected in series and according to the collector circuit of a transistor switch with a common