[bouda]

I installed a cavy electric fan on my S10 to increase milage and performance. I used a wireing kit with a relay and adjutable thermostat.


I want the fan to stay on for about five minutes after the ignition is turned off. If I put a capacitor or something like that on the switched side of the relay I should be able to do this right?

I know almost nothing about capacitors, what sizes they come in, or where to get them.

Help me out.

 

[Smaart Aas Saabr]

You mean like an RC circuit?

I would just use a timer IC and make that like that...

or switch it with the key like everyone else

 

[bouda]

RC circuit?

I googled timer ic and got confused.

I've got it on ignition switched power now, but I want it to stay on after the ignition is switched off.

 

[bouda]

 

[dauntlessVsix]

The capacitor you would need to accomplish this with a RC (resistor and capacitor) timing circuit is too large to be practical.

The easiest way I can think of off hand to do what your asking would probably be to build a simple circuit using a 555 timer chip with a transistor on it's output, providing enough current to run the relay.

You can buy a timer designed for use in industrial controls, but those are probably more expensive than you'd like.

On another note, why you would want to run the fan that long after the car has been shut off?

 

[bouda]

On another note, why you would want to run the fan that long after the car has been shut off?

Because I'm out of work for a week and I'm bored.

But anyway heat-soak and what not aside I just thought it would be cool. 5 min may be too long though I guess.

Thanks

 

[dauntlessVsix]

I did a little searching this afternoon and found this --> http://www.smarthome.com/7279.html
It will do what your asking and more. Plus, the price is pretty good.

You can set it up to trigger the relay for a set time as soon as the ignition is turned off, so it would be in addition to the relay you are currently using.

A word of caution though, it says in the manual that it cycles once when activated, so that means your fan will turn on for the set time as soon as you connect the power. Something to be aware of so everyone keeps their digits.

If you get this working good you can put one on your heater fan too. Keep ya warmer in those Minnesota winters.

 

[bouda]

I did a little searching this afternoon and found this --> http://www.smarthome.com/7279.html
It will do what your asking and more. Plus, the price is pretty good.

You can set it up to trigger the relay for a set time as soon as the ignition is turned off, so it would be in addition to the relay you are currently using.

A word of caution though, it says in the manual that it cycles once when activated, so that means your fan will turn on for the set time as soon as you connect the power. Something to be aware of so everyone keeps their digits.

If you get this working good you can put one on your heater fan too. Keep ya warmer in those Minnesota winters.

Thanks for the help, I'm gonna look into this.

 

[Water Boy]

Try these people....
http://www.the12volt.com/

http://www.electro-tech-online.com/

http://www.electronic-circuits-diagrams.com/forum/

 

[bouda]

Thanks.