Delay Power On Circuit - Need Help

**we87** · 08-22-2006, 07:50 PM

I have my carputer installed, and I am using an 600watt Inverter to power the 300watt ATX Power Supply that I use....

I built the "Ghetto SDC" shutdown controller for my inverter to start up and shut down with the car's ignition, and it all works flawlessly....excecpt for one minor thing: My inverter doesnt survive crank. So what happens when I start my car, the inverter comes on and while the start is being cranked for that few seconds, the inverter thinks the battery is dead and the led goes from green to red and the inverter no longer supplies power to the computer. I have to manually switch the inverter off and then back on again.

So what I need is some sort of a way to delay the power going to the inverter for a few seconds, that way I can let my car fully start itself before the inverter kicks on.

Can anybody point me in the right direction? What do I need? How can I get this done....

Many thanks in advance!

**yrean** · 08-23-2006, 12:20 AM

it sounds like your inverter is getting its power from your accessory(lighter outlet) so when you crank the car it drops the power. If this is the case grab your 12v, straight from the battery itself and see, if it is right to the battery, you might be able to put a small cap inline. so when the battery takes the drain from start, the cap still has power charged in it so you wont drop.

not sure your scenario just the first couple of things that popped in my head

**we87** · 08-23-2006, 02:57 AM

The inline cap is a great idea... I wonder if that would work though?

I dont use a cig lighter for power, but it doesnt come straight from the battery either. I have a 2002 Chevy Trailblazer LS, and in the back under the rear seats there is a fuse box with a 12volt bolt that I think (99% sure) that the wire is coming straight from the battery......but.....i could be wrong....

Also what I noticed is if nothing is plugged into the inverter, it runs fine during crank. But when something is plugged into it, it dies...

**Queenambeach** · 08-23-2006, 08:23 AM

Originally Posted by we87

I have my carputer installed, and I am using an 600watt Inverter to power the 300watt ATX Power Supply that I use....

I built the "Ghetto SDC" shutdown controller for my inverter to start up and shut down with the car's ignition, and it all works flawlessly....excecpt for one minor thing: My inverter doesnt survive crank. So what happens when I start my car, the inverter comes on and while the start is being cranked for that few seconds, the inverter thinks the battery is dead and the led goes from green to red and the inverter no longer supplies power to the computer. I have to manually switch the inverter off and then back on again.

So what I need is some sort of a way to delay the power going to the inverter for a few seconds, that way I can let my car fully start itself before the inverter kicks on.

Can anybody point me in the right direction? What do I need? How can I get this done....

Many thanks in advance!

Same problem I have. Inverter powers directly from the battery and doesn't survive crank.

**DarquePervert** · 08-23-2006, 09:04 AM

Inverters rarely survive crank.
Search the forums for TANK CIRCUIT for one potential solution.

**Bugbyte** · 08-23-2006, 09:16 AM

DP's right. Some survive crank, some don't. Even the same model may survive crank on one setup, but not on the other.

It sounds like you are pulling too much power from the inverter to allow it to survive crank, since it seems to do so with no load on it.

I've seen automotive relays with built in delay timers on them. Try a Google for them. But remember that you are going to either have to get on e that is rated for the load, or build a circuit that triggers higher amperage relays after startup.

I have a delay-on circuit that I use in my car for a different purpose. I bought it as a kit and soldered it together. It triggers a relay after startup. Can't remember where I bought it, but just do a search and you'll find lots of them.