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US 4,048,543 AGranted
Discharge lamp operating circuit
AssigneeGeneral Electric Company
InventorsDaniel V. Owen, David W. Knoble
Life of this patent
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AssigneeGeneral Electric Company
InventorsDaniel V. Owen, David W. Knoble
Estimating the term…
Circuit operating from a direct current source applies DC pulses to a high pressure sodium vapor lamp to improve the color properties of the lamp. The circuit includes a controlled thyristor switch in series with the lamp, an RC timing circuit for periodically turning on the switch at predetermined intervals, and an LC circuit for turning the switch off. An inductor comprising the primary winding of a transformer in series with a diode across the capacitor of the LC circuit provides for discharge of the capacitor to enable subsequent re-charging thereof, so as to produce the desired pulsed operation of the circuit, and the transformer secondary winding in series with a diode clamps the voltage of the primary winding. The disclosed arrangement prevents excessive voltage across the controlled switch and provides for the control of lamp wattage with respect to changes in lamp voltage.
A load operating circuit comprising, in combination, a direct current power source, a capacitor connected across said power source, an inductor, controlled switch means and load connecting means connected in series across said power source, a transformer having a primary winding and a secondary winding, said primary winding having a higher inductance than said inductor, first unidirectional conducting means connected in series with said primary winding across said power source, second unidirectional conducting means connected in series with said secondary winding across said power source, and control means coupled to said controlled switch means for repetitively operating the same at predetermined intervals, whereby DC pulses may be applied to the load for operation thereof.
Dependencies are inferred from the claim text.