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 circuit supplies 115 VAC (not perfectly sinusoidal) from a car battery. The circuit is from a...
This circuit is from a 1982 publication but can be assembled with BF245 for Q1 and BC548 for Q2....
This circuit was obtained in a 1973 publication. The circuit uses two operational amplifiers to...