We found this circuit in a Radio Electronics from February 1966. The transistor is from the time and so are the transformers. The circuit is battery powered. Observe the impedances.
The circuit, shown in the figure, activates a relay when the logic level applied to its input, from...
The traditional circuit was taken from a French magazine Radio Plans that no longer exists but can...
This circuit makes use of the LM11, 112 or 113 operatives and was found in a 1980s documentation. The...