This is a very simple touch sensor switch that is build with the 555 timer IC. You just need to touch the metal plate and the relay gets energised and is kept in this state for about 100 seconds, then ...

Here’s your useful and beautiful circuit for the day — [New Pew]’s vibration sensor takes manual control of the flip-flop inside a 555 timer and lights an LED in response. Use it to detect those ...

The circuit was designed to produce a circuit that will alarm a sleeping person to prevent snoring by using a vibrator instead of an audio alert so as not to affect the whole household. It contains a ...