Found in a 90s documentation, this circuit makes use of D1, a switching diode that is uncommon today. D3 is an LED. The circuit monitors 12 V batteries.
This very high input impedance circuit is suggested by Texas Instruments. The circuit can be...
We found this circuit in the August 1994 issue of Electronics Now magazine. The circuit is based on...
This bargraph circuit using LM3914 was found in the October 1980 Radio Electronics magazine. Note...