摘要 |
A half-bridge inverter is powered from a constant-magnitude DC supply voltage and provides at the inverter's output a first AC output voltage that is describable as a modified squarewave voltage. This first AC voltage is applied across a series-combination of an inductor and a capacitor, the junction between which is clamped to the DC supply voltage. As a result, a second AC voltage gets established across the capacitor; which second AC voltae is also describable as being a modified squarewave voltage. However, the phasing of the second AC voltage is delayed by approximately 90 degrees with respect to the first AC voltage; which results in the voltage across the inductor being of approximately sinuosidal waveform. A fluorescent lamp is connected in series with a ballast capacitor; and the lamp-capacitor series combination is connected across the inductor, thereby reslting in a nearly sinusoidal current being provided to the fluorescent lamp.
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