This circuit was obtained from a National Semiconductor manual from the 1990s. The circuit employs a pair of matched transistors, and the indicator is analog.
This circuit with the PA7601 was found in a 1967 Philco-Ford documentation. The circuit has a pass...
After starting, this circuit turns off the relay in a time that depends on the 4020 pulse-count. This...
This circuit is from an Electronics World of 1967. The described calculations can be applied to...