This transistorized circuit appeared in a Radio Electronics magazine in March 1958. The frequency range depends on the tuned circuit, being within a few megahertz.
This circuit, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
Found in General Electric's 1969 documentation, this circuit uses two Foto Darlingtons to control...
The output voltage of this inverter depends on the employed transformer. The circuit is from a 90s...