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.
This circuit is from a 1966 Motorola Field Effect Transistors Manual. The circuit makes use of...
This light-activated switch triggers a 6 V relay. The circuit can operate with 12 V and relays for...
This high gain small signal amplifier circuit was found in an old publication on transistors....