Time Delay Circuit Using 555 Timer

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In this tutorial, we will show you how to make a Time Delay Circuit using 555 Timer IC. The main principle of this circuit is to generate a pulse signal after some time delay. A time delay circuit can be useful for any circuit that needs a delay before the output turns on. In order to obtain time delay, we are using a 555 timer IC for this purpose. We can adjust the time of delay by changing the values of the resistor and capacitor used in the circuit.

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Hardware Components

The following components are required to make Time Delay Circuit

S. NO	Component	Value	Qty
1.	Breadboard	–	1
2.	Battery	9v	1
3.	Electrolytic Capacitor	10uF	1
4.	IC	NE555 Timer	1
5.	LED	5mm	1
6.	Ceramic Capacitor	0.01uF	1
7.	Resistors	220 ohm, 10k	1, 2
8.	Push Button	–	1

555 IC Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer

Time Delay Circuit

Connections

Make power connections by connecting Pin 4 & 8 To VCC and Pin 1 to GND.
Use a jumper wire to connect Pin 6 to Pin 7.
Add 100k Ω Resistor between Pin 7 and VCC.
Add 0.01uF Capacitor between Pin 5 and GND.
Use a 10K Ω Resistor as a Pull-up resistor and connect it to the push button and Pin 2.
Connect LED at Output Pin 3 with a 220 Ω Resistor.

Working Explanation

A time delay circuit can be made in two ways. Either we can achieve a delay before the circuit turns on or we can turn off the circuit after a delay of some time period. In this circuit, we will first turn on the circuit and after a time period of 10 seconds, it will turn off automatically. The 555 timers will operate in monostable mode and there will be only one stable state.

If we want to connect more than one LED at the output then we will connect the output of the 555 timers to a transistor first. Since the current generated by the 555 timers is not enough to drive more than one LED.