First design was with three LEDs, red green and yellow in a resistor tree basically. The problem is the red light would always be lit (when the green light went out you were in caution, and when the red light went out the battery was dead) and nine LEDs is a real pain to try and watch.
Thus the simplicity: No light normally means that when a LED comes on it will attract your attention fast. Which is the idea: Cut back power before you reverse a battery. Ideally they should all come on together; the trick is that batteries drift out of balance and this circuit will tell you which one needs an extra charge or if you need a long equalize charge.
Also I noticed that the human eye can sense light levels and turn on and off time far better than a computer. Which is neat and handy. In fact I noticed that after mowing the lawn and running around for awhile if I turned the deck off then on I could see one LED go off just a *split* second later than the other two after they all flashed on. Apparently that battery might be a little bit weaker than the other two.
Very cool stuff. I'll probably put a DB9 plug in the tractor with all the sense pins, and plug & unplug the device as needed.
Chris neil wrote:
Chris, wonder if you have looked at using a yellow also for a working range (on the low side) ?Also, are you going to share the circuit ? wombat _______________________________________________ Elec-trak mailing list Elec-trak cosmos phy tufts edu https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak