Time delay power cutoff / ignition on

**manntis** · 05-07-2009, 12:38 AM

with the carputer hooked to my battery, the batt drains to below starting voltage if I let it sit for more than a day.

What I want to do is create a time delay circuit with input for ignition on, and close the 12V batt power circuit to the carputer to turn it on, but when ignition power is cut (when I shut the car off) it will delay about 3 minutes (allowing the carputer ample time for shutdown), then cut off the 12V batt power.

Is there an off-the-shelf solution, or must I design my own?

**trader007** · 05-07-2009, 01:05 AM

check out the mp3car.com store for intelligent power supplies

**manntis** · 05-07-2009, 01:13 AM

I already have a PSU in the carputer - everything works other than the battery drain. All I need is a circuit that will cut the 12V supply a few minutes after shutdown, yet close the circuit again when the ignition signal turns on.

**almera** · 05-07-2009, 02:41 AM

You can use something like off-delay timer relay maybe?

http://www.google.com/products?hl=en...er+relay+12vdc

**trader007** · 05-07-2009, 06:45 AM

what psu do you have? i thought most of them shut off pc's after you turn the ignition off... my m2atx can specify how long you want that shutdown sequence to go for...

**Injector** · 05-07-2009, 12:49 PM

are you leaving your pc on after you shut off the car?

**Sal R.** · 05-07-2009, 01:05 PM

I wired my pc's +12V to my turbo timer via relay.

Essentially doing what I believe you're asking.

I turn the ignition off and the timer starts counting down. During the count down, the PC will shut off by way of intelligent PSU. At the end of timer count down, all power is cut to the PC.