Jeff20B

iTrader: (13)

Correct. EFI is smaller.

aGoGo

Thanks everyone, I will not make things complicated (the PID controller was just an example of what can be programmed with a PIC), and the programming part is really easy and I have full control. It is clear now that, all I am trying to do is to build a $5 flex-a-lite kit. I will even do the temp sensor (couple cent) the same way this kit is doing since the SE sensor is not a straight drop in. Thanks again, oh I will do a manual over ride switch as well located perhaps in the dash.

One last question, which Junk Yard Fan is the best?

renns

Use a pic with hardware PWM output, to control a motor drive circuit. Then you can program all the flex-a-lite features DF mentioned into your controller as well.

Sure, it's a Rube Goldberg solution that could be replaced by a thermoswitch, but the educational value of pursuing such endeavours is priceless.

Roger.

Siraniko

iTrader: (13)

just buy the cheap $25.00 auto temp controller from autozone. I finally picked one up since the price went down from $49.99 a few years back to $25.00. And get a junkyard e-fan from a fiero. Total cost for the project is less than $50 + ur own labor. Save the rest of ur $$$ for some heine

aGoGo

PWM I got you, tweaking with duty cycles! amazing what you can do with a dollar. I will try to start to get a fan then and work on it in the summer.

Thanks for all the supports, bros!

aGoGo

PWM on a relay, BTW? Cuz PIC can not drive it, that's for sure.

aGoGo

Sorry for my short posts, Renn, I think I will need to build a driving circuit too then instead of running a relay if I use PWM. Mmm... Transistor...

aGoGo

Sorry for the short post again, A solid state relay will do.

renns

No way a relay would work, as its response time is way too slow. Take a look at driving a logic-level mosfet with your pic. There should be loads of circuits floating around that would be suitable. You can also gang these devices in parallel to increase current capabilities as well if needed.

aGoGo

I had impression that, the solid state relays are actually MOSFETs. I will sketch out the details when I am not as busy in May, I will make sure to discuss about it here and let you know. Thanks much man!

kirkosaki

It's been awhile now. Did you get that circuit wrote up yet?