| 摘要 |
PURPOSE:To change optionally a mode in case when a power source is turned on, by providing a changeover switch on a connecting line between a signal switching circuit for switching a mode of a television receiver, and its controlling circuit. CONSTITUTION:A controlling circuit constituted of JKFFs 1a, 1b sets alternately an output terminal 2 and 3, and 4 and 5 to a high level. A signal switching circuit 6 has plural input terminals 9a, 9b and 9c, and selects and outputs one of an output of a television antenna and a VTR, or a video signal from a computer, by turning on or off of transistors 7, 8. When a changeover switch 11 between the controlling circuit 1 and the signal switching circuit 6 is set to an (a) side, the transisors 7, 8 become on by the output 2 and 4 when a power source is turned on, and a television set becomes a television mode. When the changeover switch 11 is set to a (b) side, the television set becomes a video mode as soon as the power source is turned on. |
