Abstract: An AC frequency conversion technique is provided by alternately switching between AC power lines at irregular times to yield a chopped sinusoid switched output waveform of given fundamental frequency. The technique does not rely on an input rectifier bridge nor on capacitive filtering to DC.

Abstract: A single to multiphase AC frequency conversion technique is provided by alternately switching between a pair of AC power lines at a plurality of sets of coordinated but irregular times to yield a plurality of chopped sinusoid switched output waveforms each of a given frequency phase shifted from each other.

Abstract: A single to multiphase AC frequency conversion technique is provided using H-switches. A plurality of H-switches are toggled in a composite coordinated but irregular timing pattern under control of logic means to yield a plurality of chopped sinusoid switched output waveforms each of a given frequency phase shifted from one another.

Abstract: An AC frequency conversion technique is disclosed using an H-switch toggled at irregular times to yield a chopped sinusoid output waveform of a given fundamental frequency. The irregular switching pattern is a departure from the classical cycloconverter frequency conversion approach. The H-switch is connected between a pair of power lines L1 and L1 and alternately switched between one and another ON state at any point in the AC cycle to yield any up-converted or down-converted output frequency of the chopped sinusoid output waveform. The output waveform has a positive half cycle during which the H-switch is in one ON state when L1 is positive with respect to L2 and is in the other ON state when L2 is positive with respect to L1. The output waveform has a negative half cycle during which the H-switch is in the one ON state when L1 is negative with respect to L2 and is in the other ON state when L2 is negative with respect to L1.

Abstract: A simple combinational technique is disclosed using one or more H-switches for start-up control and frequency conversion in an AC motor. A coordinating logic system provides H-switch toggling timing patterns yielding phase shifted voltage waveforms in the motor windings to afford a rotating field during start-up, and provides irregular switching times yielding a chopped sinusoid output waveform of converted frequency for variable speed operation.

Abstract: A start-up control technique is disclosed for an AC motor. At least one H-switch connects a motor winding to a pair of AC-supplied power lines and is switched between designated states to yield a fundamental frequency component voltage waveform in the winding phase shifted from the voltage waveform in another winding. A rotating field is provided for start-up, without energy-storage phasing capacitors or inductors.

Abstract: A simple rectified AC frequency conversion technique is provided by chopping positively and negatively rectified AC signals by alternatively switching therebetween to yield a switched output waveform of given frequency without capacitive filtering to DC. The direct AC switching provides an irregular chopped sinusoid output waveform.

Abstract: A control for establishing a rotating field in a single phase AC induction motor (10) having a rotatable output and first (12) and second (14) sets of mechanically displaced windings which are energized alternately and cyclically by a single phase AC input for establishing the rotating field to effect rotation of the output. The control includes a single phase AC input, first and second solid state switch means, 18, 20, for interconnecting the first and second sets of windings, respectively, of the motor with the AC input. The first and second switch means when conductive apply energy from the input to the first and second sets of windings, respectively, and when non-conductive prevent the application of energy from the input to the first and second set of windings, respectively.