This sensitive two-transistor circuit was found in the June 1965 Radio Electronics magazine. The circuit has low drift and uses an analog instrument. The input resistance is high.
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...