| 摘要 |
PURPOSE:To prevent the leakage of a signal, by canceling the signal which is given to a switching means of a channel circuit not selected, in a circuit which can perform switching and selection of an output signal with a switching means. CONSTITUTION:When a switch 1a of a channel A selected is at an on-terminal side, a switching transistor (TR)3a only is conductive and a signal of a signal source 7a is outputted to a common resistor 5 for output. On the other hand, in channel circuits B, C not selected, control TRs 12b, 12c are conductive. Thus, the signal from the signal sources 7b, 7c is by-passed between the collector and the emitter of the TRs 12b, 12c, and the input signal to the emitter of the switching TRs 3b, 3c can almost be canceled. Thus, the leakage of signals can be avoided. |
