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, obtained from the component manual used, has an ultra narrow 1 kHz range given by...
Found in a 1967 Delco documentation, this circuit can deliver power from 40 to 50 W at 8-ohm load....
This traditional configuration from a simple 12 V source is from a 1977 publication. The...