An alternating current conditioner is provided with a magnetic structure that provides smoothing, transient suppression, ride through and power factor correction. The structure has a gapped magnetic core and primary and secondary windings. A shunt is provided between the primary and secondary, with the gap being on the primary side. A capacitor is in series with the secondary winding. The capacitor and the shunt inductance provide an LC low pass filter. The inductance caused by the gap cancels the capacitive effect of the LC filter.
A ferroresonant transformer includes a three-legged magnetic core. The core includes a center leg, and first and second flanking legs. Each of the center and flanking legs have respective first and second longitudinal ends. The first flanking leg is positioned at an opposite side of the center leg relative to the second flanking leg. A first end-connecting portion magnetically couples the first ends of the center and flanking legs, and a second end-connecting portion magnetically couples the second ends of the center and flanking legs. The center leg defines a substantially non-magnetic space, such as an air gap, along a magnetic flux path extending along the center leg from the first end-connecting portion to the second end-connecting portion in order to reduce the total harmonic distortion of the ferroresonant transformer.
A ferroresonant ballast for regulating the current level of gas discharge lamps includes a magnetic core for supporting coil windings. A first or input coil is wound about the magnetic core for supplying a changing input voltage. A second or capacitor coil is wound about the magnetic core and is induced by the first coil to generate an output voltage across an output or resonant capacitor. A third or lamp coil is wound about the magnetic core and coupled to a gas discharge lamp which is regulated at a constant voltage in response to the voltage generated across the output capacitor. The ferroresonant ballast may include a control circuit and inductor that is switchable coupled to the output capacitor for simulating core saturation.
A power factor corrector includes a power stage that is electrically coupled to a controller. The controller is configured to receive a rectified AC voltage signal, summed with a reference level, and compare the received signal to a ramp signal. When the ramp signal exceeds the rectified AC voltage signal, the controller turns on a switch within the power stage. The switch is turned off synchronously with a periodically generated switch mode power supply drive signal.
