This circuit detects when a powered circuit suffers a malfunction, lighting an LED. The supply voltage can be changed according to the monitored load.
This is the basic configuration of a function generator with the 8038 integrated circuit (uncommon...
This filter for receiving audio in telegraphy was found in a magazine 73 for radio amateurs, in an...
This circuit amplifies VHF signals in the two-meter range and is very critical, especially...