Abstract: The present invention relates generally to a simple, low cost ballast for fluorescent lamps that incorporates an integrated circuit and a number of ballast protection functions to cost effectively enhance its reliability. End of lamp life circuitry is provided to shut down the ballast when rectification currents due to lamp aging exceed a predetermined level. This circuitry also functions to stop the ballast operation when the lamp's voltage exceeds a predetermined cutoff level for a set period of time. Re-ignition circuitry is provided that restarts the ballast when new lamps are installed without shutting off the ballast. Multiple striking attempt circuitry is provided that initiates a predetermined number of striking attempts such that cold or old lamps are quickly ignited without the introduction of excessive flickering.

Abstract: The present invention relates generally to a simple, low cost ballast for fluorescent lamps that incorporates an integrated circuit and a number of ballast protection functions to cost effectively enhance its reliability. End of lamp life circuitry is provided to shut down the ballast when rectification currents due to lamp aging exceed a predetermined level. This circuitry also functions to stop the ballast operation when the lamp's voltage exceeds a predetermined cutoff level for a set period of time. Re-ignition circuitry is provided that restarts the ballast when new lamps are installed without shutting off the ballast. Multiple striking attempt circuitry is provided that initiates a predetermined number of striking attempts such that cold or old lamps are quickly ignited without the introduction of excessive flickering.

Abstract: An electronic ballast having end of lamp life and overheating protection, and automatic reignition and multiple striking capabilities includes AC/DC rectifier, PFC/boost, inverter, and ballast protection and control circuits. The ballast protection and control circuit is operable to place the ballast in a protected state when the lamp load connected to the ballast reaches an end of lamp life condition or the ballast overheats. The ballast protection and control circuit also automatically ignites the lamp load when it is connected to the ballast and generates multiple striking attempts for hard to strike lamp loads. The ballast may be connected to AC or DC power sources and different types of lamp loads, and may include various different types of inverter circuits.

Abstract: An electronic ballast having end of lamp life and overheating protection, and automatic reignition and multiple striking capabilities includes AC/DC rectifier, PFC/boost, inverter, and ballast protection and control circuits. The ballast protection and control circuit is operable to place the ballast in a protected state when the lamp load connected to the ballast reaches an end of lamp life condition or the ballast overheats. The ballast protection and control circuit also automatically ignites the lamp load when it is connected to the ballast and generates multiple striking attempts for hard to strike lamp loads. The ballast may be connected to AC or DC power sources and different types of lamp loads, and may include various different types of inverter circuits.

Abstract: A multiphase induction motor system is disclosed. The system comprises a motor having at least five phases and comprising a stator and a rotor. For each phase, the motor receives a command current to power the motor, where the command current has a fundamental frequency. A processor determines, for each phase, at least one harmonic component of a signal indicative of the fundamental frequency, generates a command current from the harmonic component and the fundamental frequency, and supplies the command current to the stator. A method for operating a multiphase induction motor system is disclosed. A first command current is supplied to a motor having at least five phases, where the first command current powers the motor. The first command current has a fundamental frequency, and the motor comprises a stator and a rotor. For each phase, at least one harmonic component of a signal indicative of the fundamental frequency is determined.