Abstract: The alternator has a stator (12) with a rotor (10) mounted for rotation therein. The armature and field windings (20, 22, 24; 18) are both carried on the stator. The rotor is mechanically driven so as to rotate within the stator. Both the rotor and stator have poles (14; 16) formed at regular spacings on facing surfaces thereof so that as the rotor is rotated, rotor poles rotate past the field poles which are formed on the stator. The rotor poles are regularly spaced about the rotor such that at certain rotor positions all rotor poles are opposed to alternate field poles. Field coils (18a, 18b) are provided, each wound about a corresponding one of the field poles. An excitation circuit (FIG. 4) applies an excitation potential to the field coils such that field coils about adjacent field poles produce oppositely directed magnetic fields. The polarity of the this excitation potential is reversed each time the rotor poles become opposed to alternate field poles.

Abstract: Testing appartus and method for testing a regulator for switching current to an external load device in response to applied voltage, e.g., field current of an alternator. This tester is arranged to enable accurate determination of regulated voltages and operates to apply load circuitry to simulate in a closed loop mode of operation the operation of the regulator in its operating environment. A power delay circuitry is connected across the terminals of the regulator and supplies load current to a third terminal when the regulator is turned on by charging a capacitor in the delay circuitry. When the charge on the capacitor reaches a high limit, the regulator switches off and load circuitry is switched on to ramp the capacitor voltage downwardly until the regulator again switches on. The load circuitry at that time switches off. An auxiliary power supply is effective when the regulator is switched on to supply additional load current.

Abstract: A field regulating circuit for a brushless alternator or the like in which a field winding is disposed on a rotor and energized from the secondary winding of a rotary transformer which has its primary winding connected to be energized from a circuit controlled by an oscillator and wherein the frequency of the oscillator is varied in response to a voltage sensing circuit providing a potential which varies with the output of the alternator, the output of the oscillator effecting the generation of first and second pulse trains with the trains being 180.degree. out of phase and effecting energization of the primary of the rotary transformer by current pulses of a fixed width with the current pulses caused by the first and second pulse trains flowing in different directions through the primary winding of the brushless transformer, the pulse trains have pulses of fixed duration which is substantially equal to a half period of the oscillation for the frequency of the oscillator for supplying full field current.