TV receiver power supply circuit - is switched from stand by to full operating voltage using thyristor in switching circuit

摘要

The power supply has two rectifier sections for the normal operating and standby voltages. The supply is changed over by an electronic switching circuit which includes a thyristor between the a.c. input point of the rectifier for the high voltage and the path of the low voltage connection. A control voltage from the TV receiver is applied to the control electrode of the thyristor to initiate the voltage changeover. The a.c. voltage at the input to the high voltage rectifier is also applied to the control electrode which has a connection for a capacitor and also a diode connected to earth. ADVANTAGE - Switching load is reduced and circuit is simplified.