The figure shows how to obtain a pulsating continuous signal from an alternating signal using only one diode. The load resistor depends on the application.
This circuit was found in a 1975 documentation. Current general-purpose transistors can be used,...
We found this circuit in a publication for radio amateurs in 1974. The bipolar transistors can be...
This conventional humidity or water alarm circuit was found in an English documentation from 1974....