EMERGENCY ALARM BROADCAST RECEIVER

摘要

PURPOSE:To release the emergency alarm broadcast transmission/reception state at the time of channel switching only by making a defeat pulse from a channel selection circuit ineffective at turning on/off of a power switch of a television receiver. CONSTITUTION:A change in a collector voltage of a transistor (TR) 15 for driving a relay generated at the on/off state of the power switch is processed by a leading/trailing edge differentiation circuit 22. At output of the circuit 22 and a defeat pulse outputted from a channel selection circuit 6 are ORed exclusively by a gate circuit 19. Then only the defeat pulse at turning on/off of the power switch is fed to an emergency alarm broadcast decoder circuit 8. Thus, the emergency alarm broadcast reception state is not released by the turning on/off of the power switch and the emergency alarm broadcast reception state is released at the channel changeover only.