TELEVISION RECEIVER STANDBY POWER SUPPLY

摘要

In a power supply for a remote controlled television receiver, a bridge rectifier includes first and second unidirectional current conducting devices, an output terminal, a current return terminal and two input terminals. A remote control circuit generates an on/off command signal. A source of alternating voltage available during both states of the command signal is coupled between the two input terminals. A first direct voltage is developed between the output and current return terminals during both the on and the off states of the command signal upon alternate conduction of the two unidirectional current conducting devices. A first power supply is coupled between the bridge rectifier output and current return terminals and is responsive to the command signal for developing an operating potential from the first direct voltage only during the on-state of the command signal. A load circuit is energized by the operating potential to draw power from the bridge rectifier output terminal. The remote control circuit is energized by a standby DC power supply that employs one of the bridge rectifier unidirectional current conducting devices to develop a second, lower magnitude direct voltage that energizes the remote control circuit during both the on and off states of the command signal. The standby power supply includes a filter circuit having an input terminal coupled to one of the unidirectional current conducting devices of the bridge rectifier for half-wave rectifying and filtering the alternating voltage. The second direct voltage is developed between the filter output and current return terminals.