The figure shows a multi-channel touch switch composed of TTL and non-gate, which has the characteristics of simple structure and easy installation and debugging. When the power is turned on, the voltage across C1 cannot be abrupt, so the collector of BG1 is “0”. At this time, the source voltage of BG2 is “1”, and the RS flip-flop composed of F1 and F2 is set to “0”. "At this time, the RS flip-flops in all the units are also set to "0", the output terminals are also "0", and the LEDs are not lit. When C1 is charged, the collector voltage rises to "1" and the trigger is triggered.

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