Abstract: A current control that employs a magnetic amplifier and an active feedback circuit. The feedback circuit establishes the effective operating current of the amplifier at a fixed point. The magnetic amplifier includes a pair of oppositely wound gate windings, a bias winding and a control winding. The gate windings are driven by an oscillator driver that generates a gate winding current and a gate winding voltage. A reference voltage and the gate winding voltage are applied to a feedback amplifier and the feedback circuit. When the gate winding voltage becomes equal to the reference voltage, the feedback circuit is stable and the gate winding current is set to a desired zero current operating point.

Abstract: A solar array maximum power point tracking system for regulating the power output of a solar array associated with a spacecraft. An on-board computer measures the bus voltage and current from the solar array and generates a power calculation of the solar array power output. The on-board computer applies a first reference signal to a remote error amplifier representative of an incremental change in the solar array power. Additionally, the solar array bus voltage is applied to the remote error amplifier such that the remote error amplifier senses the solar array bus voltage and generates an output voltage indicative of the change of the solar array power. The output voltage of the error amplifier is applied to a power processor unit. The output voltage from the remote error amplifier and the bus voltage are applied to a power stage within the power processor unit. The power stage generates an output current that is applied to an arcjet thruster.