This circuit is from an American 80's documentation. The integrated circuit is from the time and the sensor consists of a smoke chamber measuring its transparency change.
This 0.5W amplifier was found in a publication of the 1980s. The output transistors can be the...
This configuration was found in old documentation and is valid for most general purpose NPN...
This SCR circuit was found in an American 1980s documentation. The circuit is still current,...