wow thats almost identical to the first thing i ever built which was a 12v indicator for a car battery, used a 741 opamp and a standard diode for the zener so one side of the opamp was held at 0.6v and the variable side was set similar, way back in 1977 lol, we fitted it into my grandads vauxhall viva (uk car) was always good to see the red and green led on together when we got in the car, then it would go red as the car was cranking to start and then to green when started and the alternator started to charge the battery. I cant remember if it had any feedback to make a bigger dead spot / hysteresis in the middle region. makes me want to build a new one lol
wow thats almost identical to the first thing i ever built which was a 12v indicator for a car battery, used a 741 opamp and a standard diode for the zener so one side of the opamp was held at 0.6v and the variable side was set similar, way back in 1977 lol, we fitted it into my grandads vauxhall viva (uk car) was always good to see the red and green led on together when we got in the car, then it would go red as the car was cranking to start and then to green when started and the alternator started to charge the battery.
I cant remember if it had any feedback to make a bigger dead spot / hysteresis in the middle region.
makes me want to build a new one lol
Very cool :)