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 is a bridge for the measurement of low value resistances and high values too. The circuit...
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...
We found this audio preamplifier circuit with a 741 operational in a 1976 publication. However,...