Abstract: A relatively high efficiency, relatively light weight, relatively small electronic ballast or AC power controller for use in aircraft and elsewhere for controlling a fluorescent lamp load or other load includes an EMI filter, a multi-purpose transformer, a power conversion stage and a control circuitry stage. The ballast or controller operates to increase or decrease the voltage of the incoming sine wave AC voltage through a charging path for an energy storage inductor choke cooperating with an energy storage capacitor wherein the charging path for the capacitor is different from the discharge path of the capacitor to isolate the load from the charging of the capacitor and thus to provide an output to the load which is independent of the charging path and which is out of phase with the incoming waveform.

Abstract: A relatively high efficiency, relatively light weight, relatively small electronic ballast or AC power controller for use in aircraft and elsewhere for controlling a fluorescent lamp load or other load includes an EMI filter, a multi-purpose transformer, a power conversion stage and a control circuitry stage. The ballast or controller operates to increase or decrease the voltage of the incoming sine wave AC voltage through a charging path for an energy storage inductor choke cooperating with an energy storage capacitor wherein the charging path for the capacitor is different from the discharge path of the capacitor to isolate the load from the charging of the capacitor and thus to provide an output to the load which is independent of the charging path and which is out of phase with the incoming waveform.

Abstract: A method is described for controlling synchronous motor torque, utilizing a three-phase switch connected in a circuit to the input of a polyphase synchronous motor, and a switch control circuit. The switch control circuit senses the AC voltages input to the synchronous motor and produces signals that open and close the three-phase switch in phase with the input motor voltage, producing positive motor torque during normal operation. If input AC power is lost, the switch control circuit acts to prevent a reverse flow of high current from the motor from entering the power source bus. When input power, after a short time, returns, the switch control circuit acts to close the three-phase switch in such a manner as to permit only real power applied to the synchronous motor and thus positive torque that accelerates the motor speed and quickly restores the motor to synchronism with the input power source.