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US 7,256,549 B1Granted
Three electrode arc-discharge lamp
AssigneeHewlett-Packard Development Company, L.P.
InventorsDonald L. Michael, Matthew Beasley
Life of this patent
Estimating the term…
Abstract
A method of operating an arc discharge lamp that has first and second electrodes is described. First, the first electrode is heated with a third electrode with a first arc until the first electrode temperature is sufficiently elevated to allow for thermionic emission. Then, a first voltage is applied between the first and second electrode at a voltage less than 1000 volts to create a second arc.
Claims17
An arc discharge lamp, comprising:
- an assembly enclosing an ionizable medium;
- a first, second, and third electrodes sealed within the assembly, the first electrode separated from the second electrode by a first distance, the first electrode separated from the third electrode by a second distance less than the first distance;
- a ballast circuit configured to use the first electrode as an anode and the third anode as a cathode to initiate a first arc at a first voltage, and configured to use the first electrode as a cathode and the second electrode as an anode to initiate a second arc with a second voltage after the first arc is initiated, wherein the second voltage is less than 1000 volts and the first voltage is less than 10,000 volts;
- and
- a temperature sensor thermally coupled to the first electrode and wherein the second voltage is not applied until the temperature sensor detects a predetermined temperature of the first electrode.
2 more elements
An arc discharge lamp, comprising:
- an assembly enclosing an ionizable medium;
- a first, second, and third electrodes sealed within the assembly, the first electrode separated from the second electrode by a first distance, the first electrode separated from the third electrode by a second distance less than the first distance;
- and
- a ballast circuit configured to use the first electrode as an anode and the third anode as a cathode to initiate a first arc at a first voltage, and configured to use the first electrode as a cathode and the second electrode as an anode to initiate a second arc with a second voltage after the first arc is initiated, wherein the second voltage is less than 1000 volts and the first voltage is less than 10,000 volts wherein the ballast circuit further includes an ignition transformer connected to the third electrode and wherein a current required to maintain the arc between the first electrode and the second electrode does not flow in the ignition transformer.
1 more element
An arc discharge lamp, comprising:
- an assembly enclosing an ionizable medium;
- a first, second, and third electrodes sealed within the assembly, the first electrode separated from the second electrode by a first distance, the first electrode separated from the third electrode by a second distance less than the first distance and wherein the first electrode has an aft portion and a tip portion and is suspended bV Vogel mount members and the third electrode is positioned near the aft portion of the first member;
- and
- a ballast circuit configured to use the first electrode as an anode and the third anode as a cathode to initiate a first arc at a first voltage, and configured to bombard electrons from the third electrode to the first electrode causing the first electrode to heat until a second arc is initiated at a second voltage between the first electrode and the second electrode.
1 more element
An arc discharge lamp, comprising:
- an assembly enclosing an ionizable medium;
- a first, second, and third electrodes sealed within the assembly, the first electrode separated from the second electrode by a first distance, the first electrode separated from the third electrode by a second distance less than the first distance;
- and
- a ballast circuit configured to use the first electrode as an anode and the third anode as a cathode to initiate a first arc at a first voltage, and configured to bombard electrons from the third electrode to the first electrode causing the first electrode to heat until a second arc is initiated at a second voltage between the first electrode and the second electrode and wherein the ballast circuit further includes an ignition transformer connected to the third electrode and wherein a current required to maintain the arc between the first electrode and the second electrode does not flow in the ignition transformer.
1 more element
A method of operating an arc discharge lamp having first and second electrodes, comprising:
- heating the first electrode with a third electrode with a first arc until the first electrode temperature is sufficiently elevated to allow for thermionic emission;
- and
- applying a first voltage between the first and second electrode at a voltage less than 1000 volts to create a second arc;
- wherein heating the first electrode includes a first circuit having a first current, and wherein the applying of a first voltage between the first and second electrode includes supplying a second current and wherein the second current does not flow within the first current.
1 more element
Dependencies are inferred from the claim text.