Abstract: An alternator generates output power at two or more independent voltages. The alternator has two independent output windings configured to generate the power needed for each output. Each output voltage is sensed by a regulator that controls switching rectifiers to supply the current needed to satisfy the electric power demand of the loads connected to each output. After both output load demands are satisfied, the regulator switches off the alternator field. When power demand from either load rises, the alternator field is switched on along with the respective switching rectifier to satisfy the power demand. The output voltage grounds and control signals may be electrically isolated from each other.

Abstract: An alternator regulator controls both output voltage and output current, limits input drive power and torque, and maintains output power within a prescribed range while operating over a wide ambient temperature range and shaft speed range. Voltage, shaft speed, and temperature signals are monitored, and the results are processed to determine the output current and to control the output power without exceeding the programmed limits for output voltage, output current, temperature, output power, drive power, torque, and shaft speed. This provides a predictable output power characteristic for the alternator and it eliminates high input drive power and torque excursions that occur at low temperature and certain shaft speeds. If programmed limits are exceeded over a specified interval, and the alternator does not respond to the control changes imposed by the regulator, the regulator will turn off the alternator's field current, activate an alarm circuit, and set fault codes.

Abstract: A microprocessor-based voltage regulator for an alternator reduces battery drain by removing current from the field coil during times when the alternator is not rotating, as indicated by an AC Sense signal responsive to one of the windings of the alternator prior to rectification. The field coil switch is controlled by the microprocessor to one of four duty cycles to provide effective voltage regulation with a minimum of additional hardware. The microprocessor generates a warning signal in the event of a non-standard operating condition such as drifting voltage regulation, disconnected batteries, or thermal limits that approach shut down.

Abstract: A control for an electrical charging system for selectively connecting a single alternator with two stator coil sets producing charging current at each of six outputs to the output of a first battery and the output of a second battery serially connected to the first battery output. The control comprises a plurality of switchable full wave bridge rectifiers for connecting each of the alternator outputs to one of the first battery output and the second battery output so that the one battery is charged by the alternators. The switchable rectifiers are alternatively switchably connectable to the other battery output so that the other battery is charged by the alternators.

Abstract: A load dump circuit for a wye connected electric generating machine includes a silicon controlled rectifier connected between the common terminal of the wye and one of the output terminals of the machine. A Zener diode sensing circuit is connected to the common wye terminal and to the control terminal of the controlled rectifier for rendering the controlled rectifier conductive to shunt the output windings in the event of an excessive voltage being developed thereacross as a result of a rapid load reduction or similar condition. Means are also provided to terminate field excitation during the shunting condition.

Abstract: An over-voltage protection circuit for an electric generating machine having a controlled rectifier for shunting the output winding of the machine in the event of an over-voltage condition includes impedance means connected in series with the controlled rectifier and regulation circuitry responsive to current flowing through the impedance means for preventing the excitation of the field when the controlled rectifier is conductive. An improved triggering circuit including a Zener diode and a transistor switch is employed to assure proper triggering of the controlled rectifier.