| 20110260634 | ELECTRONIC BALLAST CIRCUIT FOR FLUORESCENT LAMPS - Disclosed is a single switch integrated electronic ballast circuit for a fluorescent lamp, comprising an input for receiving a rectified DC voltage; a power factor correction portion for shaping the input line current to substantially a sinusoidal waveform and in phase with the rectified voltage, wherein the power factor correction portion includes capacitors; an energy storage portion for storing energy during dimming operations of the fluorescent lamp, wherein the capacitors also form part of the energy storage portion; an inverter with a resonant tank forming a resonant circuit for converting the DC voltage to an AC voltage to be delivered to the lamp; and a single switch for: 1) shaping the input line current to a substantially sinusoidal waveform as part of the power factor correction portion; and 2) providing a square voltage waveform across the input of the resonant circuit resulting in a substantially symmetrical waveform across the output of the resonant circuit. | 10-27-2011 |
