Polyphase converters by flux reversal: New polyphase signal generators

New polyphase signal generators of high reliability and simple construction are presented. The principle is based on the propagation of the reversed flux region in the saturable core controlled by switching operation of transistors. We use the ring core of a ferrite disk or metal sheets such as 50-percent Ni-Fe alloy, in which the flux reversal takes place from the inner to the outer periphery of the ring core due to the difference of the magnetic path length. We make small apertures in the core and arrange a suitable number of windings between the apertures. We obtain polyphase ac voltage from these windings when the saturable core itself is operated by switching transistors as in Royer´s multivibrator. We discuss the methods of shaping of the output voltage waveforms. The same kind of polyphase signal generator is also possible with the tape-wound core.