This circuit was found in a 1969 Motorola documentation. The FET admits an equivalent. The circuit has high input impedance and is powered by voltages from 6 to 30 V.
I found this circuit in a 1993 technical documentation. When we press the switch in parallel with...
Found in 1980s Electronic Engineering, this circuit uses common phototransistors as sensors. The...
This power supply was found in the December 1970 issue of Radio Electronics magazine. The...