Found in a 1964 CQ magazine this circuit consists of an automatic telegraphic key, providing the correct duration for points and dashes. The circuit can be made with a current PNP transistor.
We found this circuit in English documentation from 1996 for PCs. The circuit is for common...
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...
Using this circuit the lamps glow in sequence in a speed given by the capacitors. The SCRs present a...