Magnetic output amplifiers for digital control

WITH THE ADVENT of power-frequency magnetic-amplifier devices for logic systems, a need has developed for 10 to 1,000 volt-ampere output magnetic amplifiers conrolled by 0.1 to 1 volt-ampere logic signals. Digital output requirements are particularly stringent because the amplifier is adapted to complete, existing lines of transducer devices (e.g., solenoid valves, power contactors, small motors, etc.) intended to operate from a power line directly or through a step-down transformer where flat (0 to 5%) voltage regulation is demanded of the amplifier, although instantaneous load variation may be as great as 20 to 1 between transient and steady-state conditions.