Relay To Replicate Momentary Switch

Ok, I've searched google and the forums here and I seem to just be getting more confused.

What I would like to do is use a relay (or if there is something better for this) as a momentary switch without requiring manual intervention. Basically when the relay gets power, it shorts(closes) two wires out momentarily, and then goes back to normally open. Is this possible? Is there a better way to do this?

Thanks in advance. The assistance is greatly appreciated :-)

Google monostable multivibrator and use that type of circuit to control any normal relay

Thanks for the reply. I did look up the circuits and they look like exactly what I need, except for one thing... I don't want to send power out on the line, I only want to short two wire together. I'm no electronics guru so do you have any ideas on how to adapate one of those circuits to what I need? I can build the circuit, that's no problem, just not great at figure the circuit itself out. Thanks again :)

https://www.the12volt.com/relays/page5.asp#ctm

The capacitor allows the coil of the relay to be energized until the capacitor stores a charge, thus de-energizing the coil. The resistor bleeds off the charge of the capacitor when positive voltage is removed from the other side of the coil. You can increase the output time by simply changing the value of the capacitor. This one will give you about a 1/2 second output.

Instead of power on 30 and 87 just use those terminals as your contacts instead. It just shorts out those 2 terminals.
 

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

This isn't a one shot circuit though is it? This will continue to short out the circuit on a timeframe controlled by the cap size right?

correct me if I'm wrong... just want to make sure I understand everything right.

Basically, I have two wires, when shorted out (button pushed and released) with a momentary switch, they turn a device on. Basically what I want to do is when I start the car up, a relay (or other device/circuit) shorts out the two wires 'once' and that's it. It won't do anything again till the vehicle is started again.

This is a one shot as far as I know.

I tried the circuit out and it works as a one shot.

Otherwize they would call it a flasher.

It 's okay to think something so simple won't work.

Einstein had the same problem.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

alrighty, I'll give it a try. One additional question, that is a diode across 86/85 right? which diode should be used for that? Thanks again, I greatly appreciate it.

Just about any 3 amp switching diode will work 1N2003, 1N2004 for example

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Just wanted to say thanks. The relay, capacitor/resistor method worked perfectly. :-)

The results

NICE JOB

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Thanks :-) I actually figured out how to have the circuit NOT activate if the laptop is already on, by adding another relay and tapping into the +5vdc lead of a usb line, this way it won't turn the laptop off, if it's already on. i.e. you the car dies and you restart it immediatly. Basically for extra protection...
I'll be building that circuit tomorrow and post the pics with the others. Thanks again for pointing me in the right direction... PEACE :-)