Abstract: An adaptive AC power exchanger generates stable 120 VAC 60 Hz power from variable grid input power nominally at 220 VAC and 50 Hz. The exchanger includes an AC-DC circuit stage coupled to receive the input AC current and generate a VDC output, and a DC-AC circuit stage to generate power for a load. The AC-DC stage includes an EMI filter and surge protection circuit, a 50 Hz rectifier and a power factor correction (PFC) circuit controlled by a PFC controller to yield a 400 VDC output coupled through a bulk capacitor stack to a common connection to generate a 200 VDC voltage node. The 200 VDC and 400 VDC voltages are coupled to the DC-AC circuit including a pulse width modulator; current load limiter; an LC filter having a capacitor, dual inductors and an inductor by-pass relay; and a load disconnect relay all controlled by an AC bridge controller.

Abstract: A voltage and frequency converter device for converting a primary voltage and frequency from an electrical supply to a secondary voltage and frequency particularly useful in powering the timing mechanisms in appliances made to operate at the secondary voltage and frequency, includes a rectifier circuit for converting the alternating current oscillating at the primary frequency to direct current, circuitry for causing the current to oscillate at the second frequency and for converting the primary voltage to the secondary voltage. The output of the converter is preferably coupled only between the power source and the timing circuitry of the appliance but may also be coupled to the power circuitry for motors and the like provided the converter is further configured to generate a true sine wave output.