Patent ID: 9369075
Filing Date: 2016-06-14
CPC Classification: H02P

Claim Text:
1. A system for exciting a field coil of an alternator in order to produce a magnetic field that induces electricity in an alternator output coil assembly, the system comprising: a generator that has an excitation output coil assembly for producing alternating electricity; a rectifier having an input coupled to the excitation output coil assembly and an output, converting the alternating electricity into a direct current with an output voltage, and providing the direct current at the output; a capacitor connected to the output of the rectifier and having a capacitance that forms a resonant circuit with inductance of the excitation output coil assembly, wherein the resonant circuit causes the output voltage and direct current to vary cyclically; a switch connected in series with the field coil, the switch being operable to control application of the direct current to the field coil; a minimum current detector coupled to the output of the rectifier and operable to determine when the magnitude of the direct current is at a minimum level and in response thereto producing an indication; and a controller coupled to a control terminal of the switch and an output of the minimum current detector, the controller,