Arc lamp power supply using a voltage multiplier

• US 4,723,096 A
• Filed: 06/27/1986
• Issued: 02/02/1988
• Est. Priority Date: 06/27/1986
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Leighty, Bradley D.
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): Nickerson, Michael J.
• Application Number:
  US06/879,758
• Time in Patent Office: 585 Days
• Field of Search: 315/205, 315/207, 315/254, 315/255, 315/257, 315/276, 315/277, 315/DIG. 5, 315/DIG. 7, 315/200 R, 315/206, 315/227 R, 315/241 R, 315/245, 363/59, 363/61
• US Class Current: 315/254
• CPC Class Codes: H05B 41/384 in case of hot-restriking
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A power supply is provided for an arc discharge lamp (38) which includes a relatively low voltage high current power supply section and a high voltage starter circuit (10). The low voltage section includes a transformer (15), rectifier (24), variable resistor (26) and a bank of capacitors (28), while the starter circuit (10) comprises a plurality of diodes (D1 to D12) and capacitors (C1 to C12) connected as a Cockcroft-Walton multiplier. The starting circuit is effectively bypassed when the lamp arc is established and serves to automatically provide a high starting voltage to re-strike the lamp arc if the arc is extinguished by a power interruption.

Claims

1. An apparatus comprising at least one high voltage arc discharge lamp and a power supply circuit for the lamp, said power supply circuit comprising a relatively low voltage, high current power supply section and a high-voltage multiplier circuit connected between said low voltage section and said at least one lamp, said low voltage power supply comprising a voltage transformer adapted to be connected to an A.C. source, a rectifier bridge circuit for rectifying the output of the voltage transformer, and a variable resistance device for limiting the current to the lamp, and said multiplier circuit comprising a plurality of diodes and capacitors connected in a series multiplier configuration for momentarily generating a high voltage, under no load conditions, sufficient to establish the lamp arc, and the values of said capacitors being such that when the lamp arc is established, the diodes are biased into conduction to provide a low resistance series current path through the multiplier circuit to provide a continuous low supply voltage for the lamp from said low voltage power supply section, said multiplier circuit constituting means for automatically re-generating said high voltage momentarily so as to reestablish the arc after an interruption and restoration of power from said A.C. source.

2. An apparatus as claimed in claim 1 wherein the circuit configuration of said multiplier circuit is that of a Cockcroft-Walton multiplier.

3. An apparatus as claimed in claim 1 wherein said at least one arc discharge lamp comprises a 25 watt lamp and a cable connection is provided between the lamp and the output of the multiplier circuit.

4. An apparatus as claimed in claim 1 including a winding in said voltage transformer isolated from the A.C. source and connected to one input of said multiplier circuit.

5. An apparatus as claimed in claim 1 wherein a bank of parallel connected capacitors is connected between said variable resistance device and one input of said multiplier circuit.