This circuit was found in a 1965 General Electric manual. It is intended for cars that have negative ground. At the time there were vehicles with positive mass.
This metering bridge circuit uses one power supply only. The operational ones depend on the...
This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference,...
This 1967 Raytheon circuit uses an optical coupler of the era and has a range of 800 to 200 Hz....