Abstract: A method for reducing current ripple at an output of a power supply includes sensing an alternating current (AC) input voltage waveform; determining a correction factor for a switching frequency of the power supply based on the sensed AC input voltage; and applying the correction factor to the switching frequency of the power supply to modify the power supply switching frequency. A modification of the switching frequency synchronizes the switching frequency of the power supply to the AC input voltage waveform.

Abstract: A solid state driver to adapt current ripple characteristics therein, at least partially based on operating characteristics of a solid state lighting device operated by the driver, is provided. The driver senses operating voltage, operating current, or a combination of operating voltage and operating current of a solid state lighting device. The driver stores pre-determined current ripple percentage settings in a data structure, for example, in a controller circuit. The driver selects and implements one of the pre-determined current ripple percentage settings based on one or more of the sensed operating characteristics of the solid state lighting device, to improve efficiency, to reduce the operating frequency, and/or to lower the operating temperature of one or more components of the driver.

Abstract: Programmable drivers (or power supplies) for solid state light sources are disclosed, on which output regulation is improved to expand the dimming range to 1% and reduce and/or remove flicker. Additional fault conditions are set up to avoid latching, and thus provide for a controllable restart feature. Such drivers include an isolated half bridge resonant converter with an improved control approach designed to regulate very low current though primary side in a feed-forward loop. Such drivers include both digital and analog loops that improve the performance in steady state and/or during transients, particularly for a lighting load, in comparison to a single full digital control.

Abstract: A solid state driver to adapt current ripple characteristics therein, at least partially based on operating characteristics of a solid state lighting device operated by the driver, is provided. The driver senses operating voltage, operating current, or a combination of operating voltage and operating current of a solid state lighting device. The driver stores pre-determined current ripple percentage settings in a data structure, for example, in a controller circuit. The driver selects and implements one of the pre-determined current ripple percentage settings based on one or more of the sensed operating characteristics of the solid state lighting device, to improve efficiency, to reduce the operating frequency, and/or to lower the operating temperature of one or more components of the driver.

Abstract: Programmable drivers (or power supplies) for solid state light sources are disclosed, on which output regulation is improved to expand the dimming range to 1% and reduce and/or remove flicker. Additional fault conditions are set up to avoid latching, and thus provide for a controllable restart feature. Such drivers include an isolated half bridge resonant converter with an improved control approach designed to regulate very low current though primary side in a feed-forward loop. Such drivers include both digital and analog loops that improve the performance in steady state and/or during transients, particularly for a lighting load, in comparison to a single full digital control.

Abstract: A ballast including a driver circuit, a filament heating circuit, a current detector circuit, and a control circuit is provided. The driver circuit generates an oscillating current signal. The filament heating circuit heats filaments of a lamp connected to the ballast and includes a heating transformer with primary and secondary windings and a switching circuit. The primary winding is connected to the driver circuit and the switching circuit. The secondary winding is connected to the primary winding and may be connected to the lamp. The duty cycle of the switching circuit controls current provided from the driver circuit to the primary winding to heat the lamp. The current detector circuit is connected to the switching circuit and detects a parameter of the current in the primary winding, which indicates the number of lamp filaments connected to the ballast. The control circuit controls the driver circuit based on the detected parameter.