The present invention is broadly directed to the field of high efficiency phase modulated DC-to-AC or DC-to-DC power converters (i.e. power amplifier).
In the prior art there have been DC-to-AC power converters utilizing pulse-width modulation such as is shown in the publication "Four Quadrant Bilateral Power Converter", by Paul U. Lind, GTE Automatic Electric Laboratories, in PCI Proceedings of March 1982, P142-150.
The present invention is an improvement over the prior art in the use of a phase modulated system in contrast to a pulse-width modulation system, the present phase modulating system overcoming many of the problems and limitations of the prior art. It is useful in DC-to-AC power conversion, and in DC-to-DC power conversion where all the DC outputs are individually regulated. The apparatus can convert DC to power of any frequency or voltage level. The apparatus provides four quadrant operation of the circuit so that it is usable in noninterruptable power supply applications in which when the battery voltage is low, the battery is charged backward through the circuit from the AC source. The invention is also advantageous for use in general amplifiers such as audio amplifiers and instrumentation amplifiers, in servodrivers, step motor drivers and the like.