Constant frequency alternator

Abstract

A double induction dynamo electric machine of the exciter-generator type provides an AC electrical output that has a substantially constant frequency characteristic by using a closed frequency loop arrangement without requiring electronic controls or, in most instances, continuous application of an externally derived AC excitation signal. Moreover, the machine preferably provides such AC electrical output with a substantially constant voltage characteristic as the load current varies, without electronic voltage feedback controls. The machine includes an exciter for developing an AC signal, a generator excited by such AC signal for generating such AC electrical output, coupling means for directly electrically coupling the generator to the exciter to provide an AC excitation signal to energize the latter to produce such AC signal and thereby to close a frequency loop, and a relationship of the exciter and generator that obtains a net cancellation of the influence of mechanical rotational frequency of the machine on the frequency of the AC electrical output therefrom.

Dependencies are inferred from the claim text.