Found in a 90s American documentation, this circuit can be used as a shield, just change the coupler for one that uses a phototransistor.
This power control for powers up to about 10 W uses wire potentiometers in an arrangement that...
This simple transistor test circuit was found in Radio Elecronics magazine from October 1961. It...
Another triggered oscillator that we found in the November 1984 Radio Electronics magazine. The...