wsinsle wrote:

I got this low fuel light to work on the test bench. The varable resistors adjusts where the light comes on. Did not test the oil and water but feel they are simular so theyshould work. Water is hooked up opposite so light comes on on the high end of the scale. If you only want one LED you can connect the 3 outputs together and use just 1 LED. Did not post the pic of the power supply figured you had that.

So...you are planning on an LED warning light for the Oil and Temp as well as the fuel?  That's actually a pretty cool idea.  That's a pretty neat mess of circuitry. 

Yes, I'm still interested and I'll be happy to trade my "Gas Gauge Gage" sender adjusting how-to and my  windshield/backlite trim replacement how-to for a copy of  that skizzy.

Email: efi4u@bresnan.net

Good Job, wsinsle

Well, I've been working on the new 66 fuse panel and harness all day so I went and took my shower, got my evening libation, and now I'm thinking clearly...or more so.

Does that IC have enough V out and I out to drive a small computer relay.  what I'm thinking is a guy could build a little holding ckt pretty easy to keep the light form flashing when the fuel gets low but not low enough.

Also...could this thing be supervised by a  timer so conditions would have to be met on the fuel circuit for 45 seconds or a minute before the warning light sealed in.  If they make an IC timer it could be driven with the fourth comparitor in that IC....maybe. 

You'd only want the timer and seal in ckt on the fuel.

Three minutes later:
Oh man...what fun!  I just checked and they sure do make IC timers.  Gotta do some research.

Later...and thanks again.

BB

Last edited by Bullet Bob (9/15/2013 5:29 PM)

wsinsle wrote:

Yea it’s a pretty simple circuit; the IC does all the work. One voltage input from the adjustable resistor one from the gauge. I used a 15 turn variable resistors for more sensitivity, can be bought at RS. When the negative input is higher than the positive the output turns on. Keep in mind the output is an open collector, basically when it turns on it just closes a switch to ground. If you look at the LED's are tied to positive, when the output comes on it completes the path to ground. I was thinking about a delay on the gas myself. I was thinking 30 - 45 sec for going up and down hills. If you delay it that much I don't think it will need locked in. The 555 is a very common timer. Let me know if you come up with anything. Just remember the output goes low when on.

Thanks again, wsinsle.  I found the 555 timer but will have to study a bit to figure out how to use it.  You gotta remember that all my electronic training involved filiments and cathodes and anodes and heptoads.  IC was short for Ice Cream.

BB

Last edited by Bullet Bob (9/16/2013 10:05 AM)