Abstract: A ballast protecting device is connected between an AC input voltage and a ballasted lamp. The device includes a voltage sensing block, a current sensing block, a pulse forming block, a switch block, and a micro-controller unit (MCU). The pulse forming block converts positive half cycles of the voltage and current provided by the voltage and current sensing blocks to square wave pulses, and the MCU performs a phase angle comparison between generated pulses. Upon lamp malfunction, ballast current is phase shifted. Current may also be phase shifted when there is a radical change in the input voltage. As a trend of the phase shift between current and voltage is determined by the MCU, a ballast disconnect decision is made, and the MCU actuates the switch block to disconnect the connected ballast and malfunctioning lamp.

Abstract: A power regulator for use with an AC power source includes a voltage converter having a first input and a second input. The first input is connected with the AC power source and receives AC current therefrom. The second input is connected to a controller and receives a control signal therefrom. The voltage converter generates a substantially sinusoidal regulator output signal, the amplitude of which is responsive to the control signal. The power regulator also includes a controller having a first input and a second input. The first input receives the regulator output signal and the second input receives a set point signal. The set point signal determines the amplitude of a substantially sinusoidal reference signal which is substantially in-phase with the regulator output signal. The controller generates the control signal indicative of the instantaneous difference between the regulator output signal and the amplitude of the substantially sinusoidal reference signal.

Abstract: A fluorescent lighting system connected to an AC voltage source providing a first AC voltage is disclosed. A converter circuit connected to the AC voltage source converts the first AC voltage to a DC voltage. An oscillator circuit receives the DC voltage and produces a second AC voltage. The oscillator circuit includes a series resonant circuit and a removable installed fluorescent lamp. The series resonant circuit includes a resonant capacitor and a resonant conductor in series. The lamp has first and second elements and is connected in parallel with the resonant capacitor of the series resonant circuit such that lighting current runs between the first and second elements. The second element is connected in series with the resonant capacitor and the resonant inductor and acts as a switching element. When the lamp is removed from the system, the absence of the switching element creates an open circuit between the resonant capacitor and the resonant inductor such that the oscillator circuit does not operate.

Abstract: A power regulator system provides power to an electrical load. A power level selector generates a reference signal which indicates a desired power level for the electrical load, and a control circuit connected with a AC power source interrupts flow of the AC current for periods of time responsive to a reference system from the power selector. A filtering circuit filters the output of the control circuit and generates therefrom a second output AC circuit which is smooth relative to this interrupted AC circuit. This smooth AC output is applied to the load. A relay is provided to prevent overload conditions from forming adjacent the load in the circuit. Various types of sensors may be used as the power level indicator, such sensors including the light detector as movement detectors, and other electrical sensors.