This circuit was found in an Experimenters Handbook of the 1990s. The purpose of this circuit is to keep constant the audio signal level of a system, increasing the lower signals.
This circuit can source up to 1,000 V from a 9 V battery. Output current is very low, some...
This circuit detects the presence of strong signals from spy transmitters, enabling their...
This circuit of a publication from the 70's uses a different type of power that we had already...