2 Touch Alarm Circuit ver 3.0

Another simple touch alarm that uses 555 timer IC.
schematic diagram
555 IC pinout
Part List:
R1 - 5.6 Mega ohms 1/4W
R2 - 47 kilo ohms 1/4W
R3 - 1 kilo ohms 1/4W
C1 - 22uF electrolytic capacitor rated 16V
LED - red or any LED (see led info to know more)
BUZZER - any 5v to 12v buzzer
555 IC - LM555 or any timer IC

Other versions:
Simple Touch alarm
Touch switch using Transistor
Touch Alarm ver 1.1.0
Touch switch (ON and OFF separated)


  1. can i use 1/2 w resistor for 1k instead of 1/4 w

  2. Yes you can use resistor of higher capacity.