| 摘要 |
PURPOSE:To reduce number of optical coupling circuits used for transmitting a signal between a non-charging section and a charging section by selecting plural external input signals at the noncharging part in a multi-input TV receiver. CONSTITUTION:Changeover circuits 41-43 are switched via an optical coupling circuit 30 of simple constitution offering on/off operation to apply isolation coupling between a charging part and a noncharging part from a changeover control circuit 29 of the charging part of hot chassis constitution. Thus, one of video signals at external video signal input terminals Va, Vb of the noncharging part is delivered to the charging part via an optical coupling circuit 31 being an insulation coupling circuit. Stereo input audio signals from external audio signal input terminals Aal, Aar, Abl, Abr are selected similarly switchingly and the number of optical coupling circuits is reduced by using the optical coupling circuit in common, the constitution is simplified to enhance economics.
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