Reliable trigger circuit based on silicon controlled rectifier

Abstract

The invention relates to a reliable trigger circuit based on a silicon controlled rectifier. The reliable trigger circuit comprises a gate circuit, a high-frequency oscillator, a transformer and the silicon controlled rectifier, wherein the gate circuit comprises an input end for receiving a control signal; the control signal can be used for controlling the on / off of an output end of the gate circuit; the high-frequency oscillator is electrically connected with the gate circuit, and used for inputting a generated high-frequency oscillation signal into the gate circuit; a primary coil of the transformer is electrically connected with the output end of the gate circuit; two ends of a secondary coil of the transformer are electrically connected with a gate electrode and a negative electrode of the silicon controlled rectifier respectively; a positive electrode of the silicon controlled rectifier is connected with one phase of a three-phase power supply; and a negative electrode of the silicon controlled rectifier is an output end of the reliable trigger circuit. Sinusoidal pulses are generated by a high-frequency sinusoidal pulse generator, and amplified through an amplifying circuit. Unipolar sinusoidal pulses are loaded to a control electrode of the silicon controlled rectifier through the gate circuit by means of a pulse transformer and a rectifier diode; a pulse loading moment can be controlled through a control circuit; and an inductive load can be triggered reliably.

Description

technical field [0001] The invention belongs to the technical field of control devices for three-phase motors, and in particular relates to a reliable trigger circuit based on silicon controlled rectifiers. Background technique [0002] The SCR trigger of the traditional phase control technology adopts voltage-synchronized wide pulse or double narrow pulse. When these two triggering methods are applied to the motor circuit, because the motor is a resistance-inductive load, there will be a situation where the trigger phase shift angle α is smaller than the load power factor angle φ. In addition, the working state of the motor is high voltage and high current, and there are many problems. strong interference signal. In this case, the wide pulse and double narrow pulse trigger signals often cannot reliably trigger the thyristor, resulting in a momentary phase loss of the motor, causing serious fluctuations in the motor voltage, and the motor will generate serious heat, vibrati...

AI Technical Summary

Problems solved by technology

When these two triggering methods are applied to actual circuits, there are the following disadvantages: because the working state of the motor is high voltage and high current, there are many strong interferences, and the wide pulse and double narrow pulse trigger signals are often interfered. It will not be able to trigger the thyristor reliably, causing the motor to lose phase instantaneously, causing serious fluctuations in the motor voltage, and the motor will generate serious heat, vibration, increased noise, and even over-current, resulting in the motor not operating normally

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