TV set switch:on surge protection - has thyristor line output protected by Zener diode reference bridged by capacitor

摘要

The circuit for improving the switch-on performance of television equipment using thyristor line output stages is designed to reduce the risk of damage to components due to rapid switch-on surges developing before the suppression circuits come into operation. The circuit comprises a zener diode which is bridged by a capacitor. The zener diode provides the reference voltage for the voltage regulator circuit in the equipment. At the moment of switch-on, the reference voltage is reduced until such time as the capacitor voltage reaches the zener voltage. In this way the regulator circuit is brought into full operation at the moment of switch-on so that the set operates for a short time at reduced voltage.