Free Circuit Diagram

This 555 circuit will activate a buzzer and turn on a LED lamp when you touch the probe. Here is the circuit’s schematic diagram:

lf you touch the plates, the lamp and the buzzer will be activated for a predetermined time period. The time period is determined by 100k resistor and the 10uF capacitor. You can [...]

We  can make a simple touch switch using only two inverter gates, two resistors, and two capacitors. The schematic diagram of the circuit is shown in the figure below. At power up, the output (of U1A) will be high, and the inverting output will be low because U1A gate will be triggered to ground level [...]

Many efforts has been made to make simpler circuit, and here is one result, a very simple touch switch.  You can build up to 6 similar circuit using only one 4050 chip. If you touch the “on” pad, the output will be on on remains on until you or some one the “off” pad. Here [...]