DIRVE CIRCUIT FOR SILICON CONTROLLED RECTIFIER, DEVICE AND CONTROL METHOD THEREOF

摘要

A drive circuit for a silicon controlled rectifier (SCR), a device with the drive circuit for the SCR and a control method thereof. The drive circuit for the SCR includes a drive unit, the SCR (Q1) controlled by the drive unit, a control unit for providing a drive signal to the drive unit and a direct current (DC) power supply for providing power to the control unit. An alternating current (AC) is full-wave rectified after the alternating current is stepped down by a resistance-capacitance (RC) voltage-reducing circuit, so as to generate the DC power supply. One pin of the control unit is directly connected to an AC input terminal (CN1, CN2) of the full-wave rectification circuit so as to obtain an AC zero-crossing detection signal corresponding to the zero-crossing point of the alternating current. With the RC voltage-reducing circuits provided with the same circuit parameter, a higher load-carrying capability can be obtained with the drive circuit for the SCR than other drive circuits. The circuit parameters of the elements of the RC voltage-reducing circuit can be stepped down for energy saving. The zero-crossing detecting circuit is provided with a simple structure for cost reduction.