We found this solid-state relay circuit that can function as a shield in a Radio Electronics magazine from December 1989. The optocoupler is a phototransistor type.
This circuit was found in a 90s EDN. Its purpose is to increase the efficiency of operational...
This circuit is used to match a high impedance input source with a low impedance output device...
This is an improved version of the previous circuit also found in the December 1990 Radio...