Ok guys heres what i have, i Have a high idle on my pickup truck. Its activated by just applying 12v's to one wire. the thing is when i let my truck warm up i dont want it on high idle for more then 5 minutes. So i need to make a timer type deal that when i give it a signal it will supply 12volts for 0-10 minutes. I dont know anything abought electrical stuff really other then how to use a rely. Hope you can help me out i making a gadgit to compleat this.

 

i recommend a 555 timer most common kind of timer available.

 

555? what type? how do i wire it up? how to adjust times? ect. i need a very willing person to put in plain engish to help me out. Thanks for the bit of info.

 

960 is the one i want to make basiclly, just much simpler. i only need minutes. Hope someone will come alone to save the day.

http://www.hometech.com/hts/products/automation/timers/standalone/index.html

 

The gizmo you are looking for is a "one shot" a.k.a. "monostable multivibrator."

You can make one from a 555 timer - see page 7 of this datasheet: http://www.national.com/ds/LM/LM555.pdf

You might also want to look through Tony Van Roon's tutorial: http://www.uoguelph.ca/~antoon/gadgets/555/555.html

You can trigger the one-shot with a switch which temporarily grounds the input. The 555 output can (via a transistor) drive a relay.

 

in this http://www.uoguelph.ca/~antoon/gadgets/555/555.html in figuar 8 it shows 9volts. it 12 is used will all the data in it be wrong and have to be adjusted for 12 volts?

 

This is an example of a 555 Monostable...

http://forum.allaboutcircuits.com/showthread.php?t=14018

 

wow thats some good info, still wondering if 12v would be applied it different supply's must be used? Also where can i get a test board like that? that would be very helpful.

 

Most of the parts are available from Radio Shack, if you're talking about my post.

 

yes thank you, my mind is fried trying to figure this all out and what every thing is but im learning. thanks again.

 

using your model what would i have to change to make it 0-10 minutes possibly with a potentiometer to select. im more a visual learner then mathematics. sorry if its asking alot.. I just cont know what all the k m uf ect stand for, what the values are ect.

 

Twelve volts will work just as well as nine.

 

Thanks, i found a 1-10 minut model out there... http://www.kpsec.freeuk.com/docs/timer.pdf just not to happy that the capacitors can vary as much as +- 30% of their rated value.. wonder if there is a way to make sure its more stable.

 

The 1Mohm potentiometer will allow you to adjust for any variation in the capacitor.

 

ok i got every thing working with the 9v batt. but now heres the thing. when i put 12v to the circut the .1uf fried instantly, sounded like a bottle rocket going off.. i copied the kpspec build, used a 39K resistor and a 470uf cap to set the time. worked perfect till i siwtched the 9v to 12? whats the reason for this? i thought every thing would be fine.

 

when i put 12v to the circut the .1uf fried instantly, sounded like a bottle rocket going off..

If your cap is an electrolytic, this symptom is consistent with reversed polarity, or with a cap working voltage rating less than the potential applied across it.

 

the package says high K dielectric

 

because its a high K dielectricis that y it would have failed?

 

What was the voltage rating of the cap? It would have been written on the side of the cap. I suspect it was in backwards myself, having done both over the years, but either could blow it up.

 

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