555 realy delay circuit

[stevenc_hmfc]

Hi i am making a circuit for my car. This will be triggered by the feed to the central locking motor (switch on diagram). The circuit will be providing a timed delay to allow lights to stay on for a set period of time when the central locking motoer is activated.

Can someone have a look at the circuit iv made up and see if its ok. It seems to work fine on croc clips.

**broken link removed**

 

[StudentSA]

Good Attempt.

Let me just highlight what I feel may be a few issues.

You need to have a "flyback" diode across your relay for protection.

Why is your variable resistors wiper (middle pin) connected to your output pin 3?

Pin 5 should have the 10pF straight to ground not to after the output diode.

Lastly your 555 Timer might not be able to directly drive the relay so you can use a N Channel Mosfet or leave it out your choice.

Suggestion:

 

[stevenc_hmfc]

Thanks for the reply. Tbh i dont really know what im doing hence the mistakes with the circuit. I will try this circuit and let you know. Thanks