The method of the invention in one aspect involves electronic power
control by varying the amplitude of an electrical power supply voltage,
independent of frequency, whereby the output frequency will always be the
same as the input frequency. An electrical circuit apparatus for
accomplishing this function in a specific embodiment is also disclosed
herein. The specific circuitry of this aspect of the invention uses eight
solid state switches, such as IGBT's, eight diodes, an inductor, input
and output filters and novel controlling circuitry. The controller
apparatus and methods of the invention may be used to implement all
otherwise conventional converter types, buck, boost, and inverting (and
duals of these) versions to obtain different regulating characteristics,
including galvanic isolation of the output from the input. Indeed, the
eight-switch controller can act to either buck or boost the input
voltage, and can switch between bucking and boosting during a cycle, thus
providing more control of the regulated output voltage. The inventive
methods and devices may be used in power factor correction, voltage
and/or current harmonic filtering and neutralization, line and load
conditioning, control of power transfer between two power grids, and
programmable control of surges, sags, dropouts and most other voltage
regulation problems.