Friends this is very easy circuit for automatic stair lights , light will auto off after some time .
Actually this is a simple delay timer circuit based on transistor BC547 if you want to light for extra time use 2200uf capacitor instead 1000uf
This circuit diagram constructed by using simple and easily available components.
The bulb is connected between phase line and relay N/O contact, the Pole terminal of relay is connected to the Neutral line of AC supply.
Here 230V AC primary to 12V AC 500mA secondary stepdown transformer is used.
- Parts List:- Transistor BC547
- Relay 12 Volt
- Resistor 22k , 1k 1/4watt
- Capacitor 1000uf/25volt
- Push to on Switch