Found in a 90s EDN, this circuit is indicated for power control through a 4-20 mA line. The circuit makes use of optical couplers of the time.
The circuit presented is from a 1977 Italian magazine (Elettronica Pratica). We can mount it with...
We found this circuit in documentation from Ferranti from 1968. The circuit uses transistors from that...
This circuit makes use of an old Texas Instruments component. The buzzer is also from the era. The...