Self-oscillating constant-current gas discharge device lamp driver and method

• US 20040007986A1
• Filed: 05/29/2003
• Published: 01/15/2004
• Est. Priority Date: 05/31/2002
• Status: Active Grant

• Current Assignee: Jorge M. Parra Jr, Jorge M. Parra Sr, Shmuel Ben-Yaakov
• Original Assignee: Jorge M. Parra Jr, Jorge M. Parra Sr, Shmuel Ben-Yaakov
• Inventors: Parra, Jorge M. Sr., Parra, Jorge M. Jr., Ben-Yaakov, Shmuel
• Granted Patent: US 6,936,973 B2
• Time in Patent Office: Days
• US Class Current: 315/169.1
• CPC Class Codes: H05B 41/2828 using control circuits for the switching elements H05B41/2827 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A high frequency AC current-sourcing driving that can feed electrical loads with a constant current that is independent of load resistance. The driver is a self-oscillating inverter that includes a resonant network comprising a resonant capacitor and a resonant inductor. A current comparing and toggling circuit (CCTC) is used to generate the control signals of the inverter'"'"'s power switches. Also included in the system is a DC blocking capacitor that prevents the DC voltage from reaching the resonant network.

Claims

1. An AC driver circuit for providing an improved output current regulation to a gas discharge load, said driver circuit comprising:

a square wave inverter circuit for generating a square wave voltage,

a resonant circuit including a series inductor and capacitor, said capacitor being connected across said load,

a current comparing toggling circuit (CCTC) for sensing current to said resonant circuit and commutating the inverter state whenever the input current to said resonant network is equal to a selected current of said load.

2. A high frequency alternating current driver circuit for a gas discharge device load comprising:

an inverter for generating a square wave voltage output,

a resonant network including a series inductor and capacitor, said load being connected across said capacitor,

a current comparing toggling circuit for sensing instantaneous current to the load and forcing conversion of the input square wave when said instantaneous input current drops to the level of the maximum output current.

3. An AC driver circuit for non-thermionically driving a gas discharge load, comprising:

a switch mode inverter for generating a square wave voltage output,

a resonant network including a series inductor and capacitor, said capacitor being connected across said load, and

means for causing the frequency of said inverter to be equal to the resonant frequency and said resonant circuit and act as a current source for delivering a constant current to said gas discharge load independent of the resistance of said gas discharge load.

4. An AC driver circuit for driving a gas discharge load comprising:

a switch mode inverter circuit having commutable states for generating a square wave voltage,

a resonant circuit including a series inductor and capacitor connected to said switch mode inverter, and means connecting said gas discharge load across said capacitor,

a current comparing and toggling circuit for commutating the inverter state whenever the input current to said resonant circuit is equal to a selected level of current to said load.

5. The driver circuit defined in claim 4 wherein said selected level is the maximum current to said load.

6. The driver circuit defined in claim 4 wherein said current comparing and toggling circuit includes a transformer.

7. The driver defined in claim 4 wherein said inverter is a half bridge.

8. The driver of claim 4 wherein said inverter is a full bridge.

9. The driver of claim 4 wherein said current comparing and toggling circuit includes an analog controller.

10. The driver defined in claim 4 in which said current comparing and toggling circuit includes a microcontroller.

16. The method defined in claim 10 wherein said current comparing and toggling circuit includes a microcontroller.

11. A method of non-thermionically driving a gas discharge load with a constant current that is independent of load resistance comprising:

providing a self-oscillating inverter, providing a resonant network including a resonant inductor and a resonant capacitor connected across said load, a current comparing and toggling circuit for sensing the current input to said resonant network and commutating the inverter state whenever the input current to said resonant network is equal to a selected current of the load.

12. The method defined in claim 11 wherein the step of sensing current in said resonant circuit includes a transformer.

13. The method defined in claim 11 wherein said inverter includes a half bridge.

14. The method defined in claim 11 wherein said inverter includes a full bridge.

15. The method defined in claim 11 wherein said current comparing and toggling circuit includes an analog controller.

17. A high frequency AC current sourcing driver circuit for driving electrical loads with a constant current that is independent of load resistance comprising a self-oscillating inverter circuit including power switches and a resonant network including a resonant inductor and a resonant capacitor, a current comparing and toggling circuit for sensing current in said resonant network and generating control signals for said power switches.

18. The drive circuit defined in claim 17 including a DC blocking capacitor series circuit with said resonant network.

19. The driver circuit defined in claim 17 wherein said load is a plurality of gas discharge tubes.

20. The driver circuit defined in claim 17 wherein said gas discharge device load includes at least three serially connected fluorescent tubes.