Power source apparatus

• US 7,619,368 B2
• Filed: 07/05/2005
• Issued: 11/17/2009
• Est. Priority Date: 07/05/2005
• Status: Expired due to Fees

• Current Assignee: Chao-Cheng Lu
• Original Assignee: Chao-Cheng Lu
• Inventors: Lu, Chao-Cheng
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): A; Minh D
• Application Number:
  US11/175,349
• Publication Number:
  US 20070007902A1
• Time in Patent Office: 1,596 Days
• Field of Search: 315/209.R, 315/247, 315/276, 315/291, 315/307, 315/312, 315/200.R, 315/257, 315/279
• US Class Current: 315/209.00R
• CPC Class Codes: H05B 41/2824 using control circuits for the switching element H05B41/2822 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A power source apparatus is disclosed in this invention, specifically a power source apparatus comprising a voltage amplitude control unit that employs an active power factor corrector to control the output DC voltage by applying positive or negative logic control voltage, incorporated with high frequency power source circuit and high frequency transformer, brightness of Cold Cathode Fluorescent Lamp (CCFL) or External Electrode Fluorescent Lamp (EEFL) are controllable and DC power is directly applied to DC load. Such method is accomplished by adjusting the amplitude of the supplying DC voltage for controlling the amplitude of the high frequency voltage of CCFL or EEFL, thus called Voltage Amplitude Method. Because of the characteristics of stable frequency, high resolution and linearity, VAM is broadly used in the control of luminance of discharge tubes, such as TFT-LCD TVs, LCD monitors and advertisement lamps. The impulse width controller of the present invention achieves the luminance control of CCFL or EEFL inside or outside the glow discharge zone.

Claims

1. A power source apparatus comprising

a high frequency power source circuit,

an impulse width control circuit,

a high frequency transformer and a DC power source;

the high frequency power source circuit including a self-oscillating half bridge driver or self-oscillating full bridge driver for generating oscillating frequency;

the impulse width control circuit including a plurality of an input of MOSFETs and a plurality of photo couplers connected to a capacitor from the self-oscillating half bridge driver or self-oscillating full bridge driver to control a variable impulse frequency;

the high frequency transformer having a primary winding and at least one secondary winding to supply a DC voltage output.

2. The power source apparatus as claimed in claim 1, further comprising an Active Power Factor Corrector (APFC) circuit supplying a high power factor source to the high frequency power source circuit.

3. The power source apparatus as claimed in claim 2, wherein the APFC circuit is a boost APFC circuit.

4. The power source apparatus as claimed in claim 2, wherein the DC voltage output of the APFC circuit controlled by a compensation resistor connecting in serial with an output of the plurality of the photo couplers and the compensation resistor connecting in parallel with both ends of a voltage division resistor.

5. The power source apparatus as claimed in claim 2, wherein the DC voltage output of the APFC circuit is controlled by positive or negative logic voltage so as to control brightness of a CCFL or EEFL lamps group.

6. The power source apparatus as claimed in claim 2, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from DC voltage of a source detection circuit having a ratio winding of a CCFL or EEFL lamps group.

7. The power source apparatus as claimed in claim 2, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from the DC voltage output of the DC power source.

8. The power source apparatus as claimed in claim 2, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from the DC power source or an external circuit to supply ideal voltage to a load.

9. The power source apparatus as claimed in claim 2, wherein a control coupling of the APFC circuit is a photo-coupling or a direct-coupling.

10. The power source apparatus as claimed in claim 1, wherein an oscillating frequency of the high frequency power source circuit is determined by an oscillation-related resistor RF and an oscillation-related capacitor CF.

11. The power source apparatus as claimed in claim 1, wherein the high frequency power source circuit includes the self-oscillating half bridge driver or the self-oscillating full bridge driver, sets of power MOSFETs, or at least one high frequency transformer.

12. The power source apparatus as claimed in claim 11, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver drives a plurality of power MOSFETs to transfer energy to one or a plurality of primary windings of the high frequency transformer.

13. The power source apparatus as claimed in claim 11, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver for driving one or a plurality of power MOSFETs to transfer energy to the primary windings of one or a plurality of the high frequency transformers.

14. The power source apparatus as claimed in claim 1, wherein the impulse width control circuit includes a Sawtooth Generator, DC voltage, OP Amplifier IC, a voltage comparator IC, and the photo coupler, having variable impulse frequency and variable impulse width, and controlling a frequency related capacitor or the input of MOSFETs by the photo coupler.

15. The power source apparatus as claimed in claim 1, wherein a voltage of the DC power source is controlled by a Programmable Precision References IC and a voltage divided circuit, the photo coupler stabilizing the DC voltage output by controlling frequency of the self-oscillating half bridge driver or the self-oscillating full bridge driver.

16. The power source apparatus as claimed in claim 1, further comprising a CCFL or EEFL lamps group supplied by a high voltage power source from a secondary winding of the high frequency transformer, each CCFL or EEFL lamp having an open circuit detection circuit to improve backlight quality of the lamps group.

17. The power source apparatus as claimed in claim 1, further comprising a protect circuit supplying a DC source from the DC power source protecting a CCFL or EEFL lamps group.

18. A power source apparatus comprising

a high frequency power source circuit,

an impulse width control circuit, and

a high frequency transformer;

the high frequency power source circuit including a self-oscillating half bridge driver or self-oscillating full bridge driver for driving a CCFL or EEFL lamps group;

the impulse width control circuit including a plurality of an input of MOSFET and a plurality of photo couplers connected to a capacitor from the self-oscillating half bridge driver or the self-oscillating full bridge driver for controlling a brightness of the CCFL or EEFL lamps group and generating oscillating frequency;

the high frequency transformer including a primary winding and a multiple of secondary windings for supplying a high voltage source and applying the multiple secondary windings to a DC power source.

19. The power source apparatus as claimed in claim 18, further comprising an Active Power Factor Corrector (APFC) circuit supplying a high power factor source to the high frequency power source circuit.

20. The power source apparatus as claimed in claim 19, wherein a DC voltage output of the APFC circuit is controlled by a compensation resistor connecting in serial with an output of the photo coupler and a compensation resistor connecting in parallel with both ends of a voltage division resistor.

21. The power source apparatus as claimed in claim 19, wherein a DC voltage output of the APFC circuit is controlled by positive or negative logic voltage so as to control the brightness of the CCFL or EEFL lamps group.

22. The power source apparatus as claimed in claim 19, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from a DC voltage of a source detection circuit having a ratio winding of the CCFL or EEFL lamps group.

23. The power source apparatus as claimed in claim 19, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from a DC voltage output of the DC power source to stabilize the DC voltage output.

24. The power source apparatus as claimed in claim 19, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from a DC power source or an external circuit to supply ideal voltage to a load.

25. The power source apparatus as claimed in claim 19, wherein a control coupling of the APFC circuit is an opto-coupling or a direct-coupling.

26. The power source apparatus as claimed in claim 19, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver for driving a plurality of power MOSFETs to transfer energy to one or a plurality of primary windings of the high frequency transformer.

27. The power source apparatus as claimed in claim 19, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver for driving one or a plurality of power MOSFETs to transfer energy to the primary windings of one or a plurality of high frequency transformers.

28. The power source apparatus as claimed in claim 19, wherein the APFC circuit is a boost APFC circuit.

29. The power source apparatus as claimed in claim 18, wherein an oscillating frequency of the high frequency power source circuit is determined by an oscillation-related resistor RF and an oscillation-related capacitor CF.

30. The power source apparatus as claimed in claim 18, wherein the high frequency power source circuit includes the self-oscillating half bridge driver or the self-oscillating full bridge driver, sets of power MOSFETs, or one or a plurality of high frequency transformers.

31. The power source apparatus as claimed in claim 18, wherein the impulse width control circuit includes a Sawtooth Generator, DC voltage, OP Amplifier IC, a voltage comparator IC, and the photo coupler, having variable impulse frequency and variable impulse width, and controlling the frequency related capacitor or the input of MOSFETs by the photo coupler.

32. The power source apparatus as claimed in claim 18, further comprising a protect circuit sourcing DC source from the DC power source to protect the CCFL or EEFL lamps group.

33. A power source apparatus comprising:

an Active Power Factor Corrector (APFC) circuit having an Electro-Magnetic Interference Filter (EMIF) in front of the APFC circuit, the EMIF being controlled by the APFC circuit;

a high frequency transformer having a primary winding and a plurality of secondary windings, the high frequency transformer supplying high frequency high voltage source to supply a CCFL or EEFl lamps group, and the plurality of secondary windings supplying the DC power source;

a high frequency power source circuit generating oscillating frequency and a driving signal to provide the primary winding of the high frequency transformer, including a self-oscillating half bridge driver or a self-oscillating full bridge driver, depending on a requirement of the CCFL or EEFL lamps group;

an impulse width control circuit controlling a frequency of a pulse and a width of the pulse, applying an output of a photo coupler to control an oscillation frequency related capacitor of the self-oscillating half bridge driver, the oscillation frequency related capacitor of the self-oscillating full bridge driver, or an input of MOSFETs to control a brightness of the CCFL or EEFL lamps group;

the CCFL or EEFL lamps group being supplied by a high voltage power source from the secondary windings of the high frequency transformer, each one of the CCFL or EEFL lamps group connecting to an open circuit detection circuit;

a DC power source sourcing from a plurality of high frequency sources of the high frequency transformer;

a protect circuit sourcing DC source from the DC power source to protect the CCFL or EEFL lamps group; and

an I/O Interface device including multiple sets of DC voltage output and one or a plurality of DC voltage inputs to control brightness of the CCFL or EEFL lamps group or voltage of a DC load.

34. The power source apparatus as claimed in claim 33, wherein the DC voltage output of the APFC circuit is controlled by a compensation resistor connecting in serial with an output of the photo coupler, and a compensation resistor connecting in parallel with both ends of a voltage division resistor.

35. The power source apparatus as claimed in claim 33, wherein the oscillating frequency of the high frequency power source circuit is dependent on an oscillating frequency related resistor RF and an oscillating frequency related capacitor CF, the oscillating frequency is fixed and not varied with load.

36. The power source apparatus as claimed in claim 33, wherein the oscillating frequency of the high frequency power source circuit is determined by an oscillation-related resistor RF and an oscillation-related capacitor CF.

37. The power source apparatus as claimed in claim 33, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from a DC voltage of a source detection circuit having a ratio winding of the CCFL or EEFL lamps group.

38. The power source apparatus as claimed in claim 33, wherein the DC voltage output of the APFC circuit is controlled by positive or negative logic voltage so as to control the brightness of the CCFL or EEFL lamps group.

39. The power source apparatus as claimed in claim 33, wherein the APFC circuit is controlled by positive or negative logic voltage, the positive or the negative logic voltage is from the DC power source or an external circuit to supply voltage to a load.

40. The power source apparatus as claimed in claim 33, wherein a control coupling of the APFC circuit is an opto-coupling or a direct-coupling.

41. The power source apparatus as claimed in claim 33, wherein the open circuit detection circuit connected to each CCFL or EEFL lamp is an AC Input Response type photo coupler, an input of the AC Input Response connecting in serial with a CCFL, EEFL lamp, or high frequency capacitor, and connecting in parallel with the high frequency transformer, and an output of the AC Input Response is in a serial connection.

42. The power source apparatus as claimed in claim 33, wherein the high frequency power source circuit includes the self-oscillating half bridge driver or the self-oscillating full bridge driver, sets of power MOSFETs or one or a plurality of high frequency transformers.

43. The power source apparatus as claimed in claim 42, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver for driving a plurality of power MOSFETs to transfer energy to one or a plurality of the primary windings of the high frequency transformer.

44. The power source apparatus as claimed in claim 42, wherein the self-oscillating half bridge driver or the self-oscillating full bridge driver for driving one or a plurality of power MOSFETs to transfer energy to the primary winding of one or a plurality of the high frequency transformers.

45. The power source apparatus as claimed in claim 33, wherein the impulse width control circuit includes a Sawtooth Generator, DC voltage, OP Amplifier IC, a voltage comparator IC, and the photo coupler, having variable impulse frequency and variable impulse width, and controlling the frequency related capacitor or the input of MOSFETs by the photo coupler so as to control the brightness of the CCFL or EEFL lamps group.

46. The power source apparatus as claimed in claim 33, wherein a Voltage Amplitude Method (VAM) circuit and the impulse width control circuit are used simultaneously and independently to control the brightness of the CCFL or EEFL lamps group and the DC power source.