This small tone generator was found in the November 1987 issue of Radio Electronics magazine. The phototransistor is common and controls the sounds generated. The basic frequency is given by C1.
This simple inverter was found in a 1997 documentation. Its purpose is to apply a high voltage to a...
For this circuit, the polarity of the power input does not matter, as the output terminals will...
In the figure we have the way to control an SCR with a programmable unijunction transistor (PUT)....