Precision regulated low loss high-power power supply

In an improved power supply of the kind having an AC current input and an output, the output having an output line at an output potential (V.sub.o) and a return line at zero potential, the power supply being adapted to supply a regulated output DC current to a load, with a bi-polar controller, having an output generating a control current, and a first sensor, the controller and the first sensor being adapted to control, via the control current, an instantaneous value, measured by the first sensor, of a control variable to a predetermined setting within a tolerance of less than 0.1% at 1 Hz, and with an adjustable rectifier means, a filter capacitor, and a storage inductor connected between the rectifier means and the filter capacitor, whereby the control current is electrically connected to the output line of the power supply output, the improvement comprising a decoupling inductor means adapted to AC decouple the controller output from the filter capacitor, a first potential means for supplying a first potential (V.sub.o +V.sub.1) to the controller, a second potential means for supplying a second potential (V.sub.o -V.sub.2) to the controller, a second sensor for measuring the control current and for generating a second sensor output signal, and a control unit being connected to the second sensor and to the adjustable rectifier means, the control unit being adapted to regulate, using the second sensor output signal, the adjustable rectifier means to minimize a mean value of the control current.