Power converter apparatus for a discharge lamp
First Claim
1. A discharge lamp lighting apparatus comprising:
- a plurality of cells respectively comprising a capacitor as a voltage source, and a bridge circuit of switching elements for inverting a polarity of said capacitor;
a switched capacitor circuit of one or more sets of said cells connected in series;
a discharge lamp connected as a load to output terminals of said switched capacitor circuit;
means for controlling said bridge circuits to charge the capacitors of said cells in parallel with voltage from a D.C. voltage source; and
means for connecting said capacitors in series to discharge said capacitors to supply a sinusoidal A.C. voltage to said discharge lamp;
wherein an output voltage of said switched capacitor circuit is controlled to achieve a light sustaining value and thereby stably light the discharge lamp and, wherein each of the capacitors of said switched capacitor circuit is capable of being charged for an arbitrary period of time.
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Accused Products
Abstract
A power converter apparatus in which a switched capacitor circuit includes one or more sets of cells connected in series each having a capacitor as a voltage supply source and a bridge circuit for inverting the polarities of the capacitor, the switched capacitor circuit is connected to a load, there is provided a means for parallelly charging the capacitors of the cells with a D.C. voltage source, any number of the cell capacitors are connected in series with any polarity to control supply of an A.C. output to the load. Whereby the power converter apparatus using the switched capacitor circuit can supply A.C. power with less distortion to the load without increasing the withstand voltage of the switching elements and without any need for provision of large inductors or capacitors.
99 Citations
26 Claims
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1. A discharge lamp lighting apparatus comprising:
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a plurality of cells respectively comprising a capacitor as a voltage source, and a bridge circuit of switching elements for inverting a polarity of said capacitor; a switched capacitor circuit of one or more sets of said cells connected in series; a discharge lamp connected as a load to output terminals of said switched capacitor circuit; means for controlling said bridge circuits to charge the capacitors of said cells in parallel with voltage from a D.C. voltage source; and means for connecting said capacitors in series to discharge said capacitors to supply a sinusoidal A.C. voltage to said discharge lamp; wherein an output voltage of said switched capacitor circuit is controlled to achieve a light sustaining value and thereby stably light the discharge lamp and, wherein each of the capacitors of said switched capacitor circuit is capable of being charged for an arbitrary period of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A power converter for a discharge lamp, the power converter comprising:
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a switched capacitor circuit that includes one or more series-connected cells, each of which cells includes; a voltage source in the form of a capacitor, a bridge circuit comprising a plurality of switching elements for inverting a polarity of the capacitor; means for controlling each bridge circuit to charge capacitors within a cell in parallel from a D.C. voltage source for charging other capacitors of the switch capacitor circuit, at least one of the capacitors in a cell being capable of operating as a D.C. voltage source; and means for connecting the capacitors in series whereby an output produced thereby is in the form of a sinusoidal A.C. voltage that is applied to the discharge lamp.
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Specification