This circuit was found in an American 1980s documentation. It analyzes the exhaust gas of a vehicle using a special sensor. The indicator is a milliamperimeter.
This circuit appeared in a noverber 1962s Practical Electronics. The magazine is no more, but the...
Found in a 1960s RCA manual, this circuit uses components from the era. For the indicated circuit R1 is...
This circuit is from an old publication about transistors, using types of germanium that are no...