two second ground out without pulse timer

i am an idiot wrote: He is using the positive voltage from the door lock solenoid.

Ah, missed that part. Then current's not a problem, it should be plenty.

i am an idiot wrote:

Thanks. I will grab some parts, build it and test it.

Seems to work fine. I can pretty much do a quick tap to positive with the input wire and it shows a true ground output that my alarm is seeing. When before I was using just a standard relay to flip the positive into a negative output the relay would not produce a strong enough or long enough ground output to be seen by the alarm. With the 2.2 microfarad it still seems quick so I'll try maybe use a larger microfarad capacitor and it should do the trick. I'm thinking the 4.6 mf one I almost grabbed will do just right. I gutted some old alarm brains that I had for the on-board micro relays. They work great. My plan is to build a small circuit board with two of these circuits (lock & unlock) on it that will fit in the small 2x4 project boxes. I found the same micro PCB relays online for about $0.98 each. Less if I buy more. If I buy a 20 quantity of everything I need I can get the price down to about $8.00 each or less! Quite a bit cheaper than using two $14 to $20 pulse timers. Plus it takes less room than zip-tying the two pulse timers together.

OK. I wired it up and tried it with my alarm on the test bench. What I find is that if I simply tap or pulse the input in the circuit it is not enough to produce the signal that I need, however if I hold the input to ground for about a second it will work. The relay clicks but doesn't produce the output that I need. I put my negative side of my volt meter on the ground out from the relay and connected my positive to obviously the 12 volt positive. I find that if I do a quick tap of 12 volts to the input I will only receive a flash of 8 or so volts on my meter. Yet if I hold it for a second it will give me the full 12 volts showing me I'm getting a full ground out from the relay.   I've tried this with a 1, 2.2 and a 4.7 mf capacitor. I think the problem might be in the bulk of the relay. Anyone know where to find say a lighter weight relay as in lower amperage relay? Maybe I'll try some of the ones that come in the door lock relay packs and see what I get out of them.

dualsport wrote: The MOSFETs work on voltage rather than current, so you can switch those things just by touching it with your finger.  However, because of that, they're much more sensitive to damage from static , so they'll require more careful handling.

So I guess I'll have to watch scooting my sock covered feed across the carpet just before touching them....lol