Abstract: An electric power regulator circuit for discharge of a spacecraft battery is employed for powering a load with energy stored in the battery. In order to produce a simplification of circuitry with reduction in the total number of components, the regulator circuit has two loops which share a common inductor. In a first loop, the inductor is serially connected with a gate, in the form of a first field effect transistor (FET) connected to the battery. The second loop includes the inductor with a series connection via a diode or a second FET to a capacitor which charges to feed the load. The load is serially connected via a current monitor between terminals of the capacitor, the monitor serving to sense the presence of short circuit current. The first FET is pulse-width modulated by a modulator operating in response to voltage sensed across the capacitor.