The main feature of this circuit found in an old American publication is that it is powered by the very signal it converts. The transistors are of the time and can be replaced by current types.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit is from the American magazine that no longer exists Science & Electronics,...
This circuit was found in a 1969 US documentation. It provides a signal that can be externally...