This 1967 Raytheon circuit uses a Raystor, an optical coupler with a lamp and an LDR. The circuit can be adapted to use another type of coupler.
With this circuit we can use a high impedance source to excite a low impedance output. The input is...
This circuit was found in a 90s Electronic Engineering. The circuit has the tube's critical...
Found in documentation from the 1980s, this circuit can have several adaptations to use modern...