need ideas for a high-charge warning light

[-=Charley]

recently, some components on my megasquirt board were fried after an alternator flipped out and started charing @ 17V plus. MS is fixed, but before i start it up again with the new alternator, i'd like to install some kind of warning light that activates @ ~15V just in case the regulator bones out again. yes.. i am an electronics student, but my aas degree only shows me how to use an ohm meter HAHAHA. any suggestions = mucho appreciated.

-Charley

aargh!

[albawhore]

Why not put a voltage limiting gate with an led attached, a choke with an indicator you know.

[jgerry2002]

Also your basic VDO Voltage Gauge would also be a good idea.

I had the same problem (noticed the voltage was all over the place and suddenly very high), though nothing needed replacing except the regulator on the alternator. Obviously you have other parts involved.

[RandyMolson]

Why not put a voltage limiting gate with an led attached, a choke with an indicator you know.

Wire the overflow from the voltage limit-gate to a joy buzzer mounted in the seat cushion. Then you'll be able to monitor both the frequency and magnitude of overvoltage events in a way that an idiot-light can't replicate.

[DanOKC]

I haven't done a megasquirt yet, but would reccomend if your ee student, look up basic zener regulator power supply circuits & apply it to your car. So maybe put a 15 or 16 volt zener diode to ground with appropriate size resistor in series & you have a 15 or 16 volt regulator that would be inactive at 13.8 volts if all was going well.. Would cost all of 2 bucks. 1N4744A or 45A, maybe get a 5 watt version, which would be a different #. As far as high-charge warning light, either you need a full time voltmeter on the dash, or you need to fix your charging system to be reliable, imo. Or if you like playing with LED's, you could build a simple comparator circuit to drive an LED if it went over say 14.8 volts, or look up LM3915 & LM3914 IC's if you want that circuit prebuilt to drive 10 LED's over any volt range.