| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a signal switching circuit, with which an audio video signal composed of a video signals and left and right audio signals and left and right headphone signals can be outputted while being switched to output both the signals from one jack, with simple configuration. SOLUTION: When a microcomputer 2 detects a plug is connected to a jack 1, the microcomputer 2 switches 1st-3rd switches to the side of an input terminal B. When a four-pole mini plug for outputting the audio video signal is connected, a transistor Q2 is not turned into a connected state but when a stereo mini plug for outputting the headphone signals is connected, the transistor Q2 is turned into the connected state. By detecting the presence/absence of signals at an AHDET terminal, the microcomputer 2 changes over the 1st-3rd switches.</p> |
