In this 555 timer project, I have shown how to make a time delay relay circuit using 555 timer IC to automatically turn Off the switch after a predefined delay.

You can also adjust the off delay time up to 20 minutes with a 1M POT.

In this article, I have shared the required components, complete circuit diagram, PCB layout, and all other details for this simple 555 timer project.

Time Delay Relay Circuit Diagram

In this circuit, if you want to use the 5V DC supply, then use the 5-volt relay instead of the 12-volt relay.

The delay time depends on the R2 resistor and C1 capacitor. For the constant delay time use a fixed resistor in R2, but for the adjustable off delay time, you can use a 1M POT.

I will discuss how this circuit works later in this article.

PCB Layout for Delay Timer circuit

Required Components for Time Delay Relay

555 Timer IC

BC547 NPN Transistor

1000uF 16V Capacitor (C1)

1k 0.25watt Resistors – 2 no (R3, R4)

10k 0.25watt Resistor (R1)

1M Trimmer POT (R2)

LED 5mm – 1no

1N4007 Diode

12V SPDT Relay

Pushbutton

Connectors & IC Base