Abstract A circuit for starting a gas discharge lamp connected across a high voltage direct current source. The circuit comprises a saturable core transformer having primary windings connected in parallel with the lamp, and secondary windings connected in series therewith. A capacitor is connected in series with the primary winding. Switching means are provided for discharging the capacitor through the transformer to breakdown gas in the lamp. Another capacitor is connected across the serially connected secondary windings and lamp to provide a starting current through the lamp once it has become conductive. An operating circuit is also disclosed comprising a low voltage direct current source connected in parallel with the lamp across the high voltage source with like terminals of the two sources coupled together.
A starting circuit in accordance with claim 1 wherein said switching means comprises a silicon controlled rectifier connected across said seriallY connected capacitor and primary windings.
Claim 2
Dependent Claim
32 words
A starting circuit in accordance with claim 1 wherein said switching means comprises a resistor to prevent said first capacitor from discharging through the switch itself prior to discharging through the lamp.
Claim 3
Dependent Claim
15 words
A starting circuit in accordance with claim 1 wherein said transformer has a saturable core.
Claim 4
Dependent Claim
85 words
A starting and operating circuit for gas discharge lamp having a starting circuit in accordance with claim 1 combined with an operating circuit for said lamp, said lamp operating circuit comprising: G. a low voltage direct current source connected in parallel with said lamp and said high voltage direct current source with like terminals of the voltage sources coupled together; said starting and operating circuit further comprising; H. means to prevent said high voltage direct current source from charging said low voltage direct current source.
Claim 5
Dependent Claim
17 words
A starting and operating circuit in accordance with claim 5 wherein said charge preventing means a diode.
Claim 6
Dependent Claim
45 words
A starting and operating circuit in accordance with claim 5 further comprising a third capacitor connected in parallel with said high and low voltage direct current sources with said charge preventing means in series with said third capacitor and said high voltage directed current source.
Claim 7
Dependent Claim
32 words
A starting and operating circuit in accordance with claim 5 wherein said lamp operating circuit further comprises: I. a capacitor connected in parallel with said low voltage direct current and said lamp.
Claim 8
Dependent Claim
166 words
Improved circuitry for providing a stepped-up voltage from a high voltage source of direct current across a gas discharge lamp sufficient to ionize the gas therein, and for providing sufficient current through the lamp following said ionization to cause the lamp to flash, said circuitry comprising: A. a step-up transformer having a saturable core and primary windings connected across said high voltage source through first energy storage means, and secondary windings connected across said high voltage source through said lamp; B. means for discharging energy stored in said first energy storage means through said primary windings to induce a stepped-up voltage across said serially connected secondary windings and lamp to ionize gas in the lamp and thereby make the lamp conductive, said energy discharging means providing a portion of the connection of said primary windings across said high voltage source; and C. second energy storage means connected across said high voltage source to store energy for discharge through the lamp when gas therein has been ionized.