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 is one of the channels of an amplifier suggested by Westinghouse in 1970s documentation. The circuit...
The basis of this circuit is a double T in the feedback, which has the components calculated to...
This circuit was obtained from American documentation from the 1990s. The transformer can be a car...