Two Auto-OFF Timer Circuits || 555 IC or Transistor

The Timer circuit turns ON when connection is given and turns OFF automatically after few seconds, depending on the value of Capacitor used in the circuit.

Here, I will show you two different ways to make this circuit using :

1. 555 Timer IC

2. Transistor

Pushing the push button switch turns ON the output (LED), which then turns OFF automatically after few seconds, influenced by the capacitance used.

These are the Components Required for making the circuit:

1. Using 555 Timer IC ()

• 555 Timer IC

• Momentary Switch

• Resistors: 47 K Ω, 330 Ω

• Capacitor: 100 μF

• LED

2. Using Transistor ()

• Transistors: BC 547

• Momentary Switch

• Resistors: 10K, 330Ω

• Capacitor: 100 μF

• LED

Other Requirements :

• Battery: 9V and battery clip

• Breadboard

• Breadboard Connectors

These are the Circuit Diagrams for making the circuit using :

• 555 Timer IC
• Transistor

This video shows step-by-step, how to build all these circuits.