Startup pulse fix with Jeff Shutdown Controller

**moahdib** · 03-03-2004, 07:13 AM

I found a nice and relatively easy fix for those who are using laptops or atx mobos with no auto turn on feature in bios.

Just add a relay, a cap and resistor. See image below.
You get a nice 2 second pulse on the ATX wire ( connects to ground) when you first turn on the car. Then the shutdown controller takes care of everything when you turn off the car. Basically you are getting a pulse whenever the switched 12V line goes from off to on.

This is an old drawing I made of the controller years ago and I just edited a bit.
Hope helps those of you with that problem.

If you are looking to build the whole controller go to www.carpc.tk for a detailed description of all the parts.

**Jamez_Warner** · 03-03-2004, 08:28 AM

jeff's shutdown controller can be modified to add auto turn on by adding a single capacitor to the board - ask him about it...
all that effort may have been in vain

**moahdib** · 03-03-2004, 12:51 PM

No, I have talked to him. If you add a single capacitor and resistor, when you manually turn off the computer, then turning off your car will restart it again. This doesn't happen in my drawing. You only get a pulse when turning ON. The simple relay, cap and resistor can be used for other applications like auto turning on the lilliput etc... If you use a pot you can also vary the timing of the pulse.
Well thi

This certainly beats using somethign like a DEI 528T pulse timer relay. =)

I have some pics of my modified mastero shutdown controller.
Sorry for the quality, im using my palm camera.