Automatic globe light control circuit

Automatic globe light control circuit, globe light control circuit automatically turn off globe light after some time when someone turn on it. This is simple circuit diagram of globe light control system. It used one transistor and number of resistors to control the flow of current through globe light.

Globe lights are used in homes and industrial offices. we usually turn on globe light in hurry and forget to turn off it which results in wastage of electricity. In country like pakistan where electricity is already a main issue, electrical devices can be turn off manually when they are not in use. But what if you forget to turn off it when you are in hurry. In such situation automatic control system can help us to save electricity and money. similarly automatic globe light control circuit resolve this issue and turn off globe light automatically after some time.

Circuit diagram :

Circuit diagram of globe light control circuit is given below. It used two transistors, resistors and capacitors to include delay and to turn off light automatically.

List of components for circuit :

List of components for above circuit is given below.

Category,Reference,Value,Order Code
Resistors,"R1",10k,
Resistors,"R2",150k,
Resistors,"R3",120R,
Resistors,"R4",100k,
Capacitors,"C1",220uF,
Capacitors,"C2",10nF,
Transistors,"Q1",BC547,
Transistors,"Q2",BC557,
Miscellaneous,"BAT1",6V,
Miscellaneous,"GLOBE",6V, and Switch

Above circuit diagram keep the globe light turn on for sometime after the switch button is turned on. On time can be increased by changing the value of resistors and capacitors connected with first transistor. When a push button is pressed, NPN transistor BC547 turn on due to forward braising voltage from base to emitter. At the same time capacitor C1 starts charging  through battery of 6 volt. Transistor Q1 turned on pnp transistor Q2 through collector output of transistor Q1. When push button is released, globe still remains turn on due to charge stored in capacitor Q1. globe light remain turn on untill capacitor discharge fully. So by adjusting the value of capacitor turn on time can be increased.