This 6-transistor circuit had excellent sensitivity using germanium transistors. The push-pull stage used two transformers, one drive and one output as we usually find at the time.
This circuit can be used to add a delay to a logic signal as shown by the input and output...
This circuit was found in a 1980 publication. With it we can test low and medium power NPN and PNP...
This circuit fires emitting sound when light hits the sensor. The adjustment can be a...