This is a very useful timer that can run 110/220v AC load up to 10A.
This circuit give 5 time periods from 1 minute to 60 minutes, you have to select the time by time selector switch then press START to activating the relay for running the AC load and turning OFF the load after selected time automatically.
Maximum time period in this timer is 60 minutes but if you need to higher period so you have to increase the value of 470uF capacitor or 4M resistor to higher value.
If you need this timer for DC loads so can use second circuit diagram.
Parts list:
IC 555
Transistor 2N5551
Relay 12v
Red LED
Green LED
Push switch
Selector switch
Diode 1N4007
Bridge diode 1A
Zener diode 12v 1W
Capacitor 470nF 400v
Capacitor 220uF 16v
Capacitor 100nF
Capacitor 470uF 16v
Resistor 270 ohm 2W
Resistor 30K
Resistor 1K(3pcs)
Resistor 100K
Resistor 500K
Resistor 1.5M
Resistor 2M
Resistor 4M
