2-5 sek delay of 12V compressor

[Lars'ern]

Hello!

I am going go bulid in two 12V compressors in my car, and I want a 2-5 sek deley on the start between them.

When the switch (it is a pressureswitch) is operated, relay1 switch on and compressor1 starts, after 2-5sek relay2 switch on and compressor2 starts. When the switch i off, both compressors stops.

I tryed this, but it wount work, whats wrong?
**broken link removed**

Or do someone got a better way too do this?
I am not all green, it is just too long time since I was doing some electronic


Thanks

 

[MikeMl]

Several issues. The regulator cannot work. It has no headroom. The 555 is not wired as a delay-on-start.

This should work. Compressor wiring not shown. Bypass caps not shown.

I added snubbers around the relays. D2 resets the timing network for a new cycle.

 

[Lars'ern]

Thanks!