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 traditional preamp configuration with the common emitter configuration has a polarization setting...
The FET of this circuit of a 1971 publication may be the BF245. The circuit serves as a voltage...
We found this circuit in a 90s Electronic Design. Through a capacitor it can increase the growth...