2-second power on circuit needed

nst6563 · 10-31-2007, 01:10 PM

this is sort of an odd request maybe, and I don't think it would be very hard, but I have a need of a circuit (most likely involves a relay) that upon detection of the power button on the pc, will close a circuit for 2-3 seconds.

Basically I have a bluetooth GPS that doesn't auto-power on (but it does auto-off). What I'd like to do is have a circuit that detects when the carpc is turned on, and simulate the button press on the gps receiver for 2-3 seconds to turn it on. The circuit can be located anywhere, and if this is possible I'll be installing small jumper pins connected to the power button on the GPS unit to which I can connect to the circuit easily.

can anyone help with this? Please

2k1Toaster · 10-31-2007, 01:15 PM

I think they make adjustable amp anti-thump kits. Basically a 555, a pot, and a relay. You can build one yourself (easy) or buy one (easiest) then use the amp turn on output as your delayed switch for anything. I think that would be the easiest way. And if you decide to build it yourself I am sure it can be done for under a dollar and there are millions of schematics floating around the web.

nst6563 · 10-31-2007, 03:12 PM

I never thought about the anti-thump method....that would work...but I would need it to hold the circuit closed for 2-3 seconds otherwise the gps receiver won't power on. maybe an anti-thump with a modification would work....

thanks, I'll do some searching on that idea

ajscomp372 · 11-01-2007, 11:16 PM

Go to the12volt.com and look in the "special application" relays section. If you combine a few of those circuits, you should have something that will do exactly what you need.

pRoFiT · 11-01-2007, 11:23 PM

I would use a simple RC circuit with a relay. The capacitor would have to be big though.

nst6563 · 11-03-2007, 12:46 AM

thanks for the link to the12volt.com... looks like I may be able to put something together that would work judging from what I've looked at. Only problem I'll run into is I don't need to feed +12v from the relay, just need it to simply make a closed circuit for about 2 seconds then release

What's an "RC circuit"?

I apologize, my first major was in electronics...but that was over 8 years ago now and I've forgotten most of that since I don't use it much.

2k1Toaster · 11-03-2007, 12:52 AM

RC Circuit = Resistive Capacitive Circuit

afterdigital · 11-05-2007, 08:58 PM

I'd like to know how i can have my power inverter turn on automatically when i turn my car on?

The inverter itself has an on/off switch. i would like to control this thru the car accessory switch. I'm not sure if i use a relay and how?

I've visited the12volt.com and read up some but it's over my head...

any help would be appreciated.....