Power supply and LED lamp device

• US 6,577,072 B2
• Filed: 07/10/2001
• Issued: 06/10/2003
• Est. Priority Date: 12/14/1999
• Status: Expired due to Term

• Current Assignee: Naoco Incorporated
• Original Assignee: Takion Company Limited
• Inventors: Ota, Tsutomu, Narukawa, Toshiaki, Ozaki, Kouei, Saito, Yutaka
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/869,997
• Publication Number:
  US 20020158590A1
• Time in Patent Office: 700 Days
• Field of Search: 315/185.S, 315/185.R, 315/193, 315/271, 315/272, 315/216, 315/294, 315/312, 315/322, 315/200.R, 362/227, 362/251, 362/252, 362/800, 362/806, 362/812, 363/88, 363/89, 363/80, 363/126
• US Class Current: 315/185.00R
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

An LED lamp device of the invention includes a power supply unit (102, 103) supplied with an alternating-current power supply voltage, and an LED lamp (106) constituted by one or a plurality of serially connected LEDs connected to output terminals of the power supply unit (102, 103). The power supply unit (102) obtains a rectified wave of the alternating-current power supply voltage, admits electric power for only part of a time period in which the voltage of the rectified wave corresponding to each half period of the wave of the alternating-current power supply voltage is higher than or equal to a predetermined value, and uses the electric power as power for lighting the LED lamp (106).

Claims

1. A power supply unit comprising:

a rectifying diode bridge operable to obtain a rectified wave of a power supply voltage;

an oscillator circuit;

a clock signal control circuit; and

a switched capacitor step-down circuit including a plurality of changeover switches connected in series and capable of being switched between two positions, and a capacitor connected between adjacent ones of said changeover switches, said changeover switches being capable of being switched to either of the two positions by said clock signal control circuit such that said capacitors are charged when said changeover switches are in one of the two positions and such that said capacitors are discharged when said changeover switches are in the other of the two positions, thereby supplying electric power to a load.

2. A power supply unit having two input terminals connected to an alternating-current power supply, for supplying electric power to a load connected to output terminals thereof, said power supply unit comprising:

an oscillator circuit;

a clock signal control circuit; and

two switched capacitor step-down circuits, a high voltage-side input terminal of one of said two switched capacitor step-down circuits and a low voltage-side input terminal of the other of said two switched capacitor step-down circuits being connected to one of the two input terminals of said power supply unit, a low voltage-side input terminal of said one switched capacitor step-down circuit and a high voltage-side input terminal of said other switched capacitor step-down circuit being connected to the other of the two input terminals of said power supply unit.

3. An LED lamp device comprising:

a power supply unit capable of being supplied with an alternating-current or direct-current power supply voltage; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit includes a current detection circuit, an input voltage detecting section, an oscillator circuit, a switching circuit, and a switching element, said switching circuit being arranged so as to be supplied with signals from said current detection circuit and said input voltage detecting section to perform ON/OFF control of said switching element.

4. The LED lamp device according to claim 3, wherein said power supply unit is arranged so as to receive a rectified wave of the power supply voltage and is operable to admit electric power for only part of a time period in which a voltage of the rectified wave corresponding to each half period of a wave of the alternating-current power supply voltage is higher than or equal to a predetermined value and to use the electric power as power for lighting said LED lamp.

5. The LED lamp device according to claim 4, wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form.

6. The LED lamp device according to claim 5, wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board.

7. The LED lamp device according to claim 6, wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current having a frequency of not lower than 100 Hz.

8. An LED lamp device comprising:

a power supply unit capable of being supplied with alternating-current or direct-current power; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit includes an input/output voltage detecting section, an oscillator circuit, a switching control circuit, a switching element, and a current detection circuit, said switching control circuit being arranged so as to be supplied with signals from said input/output voltage detecting section and said current detection circuit to perform ON/OFF control of said switching element.

9. The LED lamp device according to claim 8, wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form.

10. The LED lamp device claim 9, wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board.

11. The LED lamp device according to claim 10, wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current having a frequency of not lower than 100 Hz.

12. An LED lamp device comprising:

a power supply unit capable of being supplied with alternating-current or direct-current power; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit includes a rectifying diode bridge, a current detection circuit, an input voltage detecting section, an oscillator circuit, a switching circuit, and a switching element, said switching circuit being arranged so as to be supplied with signals from said current detection circuit and said input voltage detecting section to perform ON/OFF control of said switching element, and

wherein a capacitor is connected between said switching element and said LED lamp such that said capacitor is capable of being charged when said switching element is in an ON state and such that electric power is capable of being supplied to said LED lamp from said capacitor when said switching element is in an OFF state.

13. The LED lamp device according to claim 12, wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form.

14. The LED lamp device according to claim 13, wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board.

15. The LED lamp device according to claim 14,wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current having a frequency of not lower than 100 Hz.

16. An LED lamp device comprising:

a power supply unit capable of being supplied with an alternating-current or direct-current power supply voltage; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit includes a rectifying diode bridge operable to obtain a rectified wave of the power supply voltage, an oscillator circuit, a clock signal control circuit, and a switched capacitor step-down circuit,

wherein said switched capacitor step-down circuit includes a plurality of changeover switches connected in series and capable of being switched between two positions, and a capacitor connected between adjacent ones of said changeover switches, and

wherein said changeover switches are capable of being switched to either of the two positions by said clock signal control circuit such that said capacitors are capable of being charged when said changeover switches are in one of the two positions and such that said capacitors are capable of being discharged when said changeover switches are in the other of the two positions, thereby lighting said LED lamp.

17. The LED lamp device according to claim 16, wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form.

18. The LED lamp device according to claim 17, wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board.

19. The LED lamp device according to claim 18, wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current having a frequency of not lower than 100 Hz.

20. An LED lamp device comprising:

a power supply unit capable of being supplied with alternating-current power; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit includes an oscillator circuit, a clock signal control circuit, a current detection circuit, and two switched capacitor step-down circuits,

wherein a high voltage-side input terminal of one of said two switched capacitor step-down circuits and a low voltage-side input terminal of the other of said two switched capacitor step-down circuits are connected to one of two input terminals of said power supply unit, and

wherein a low voltage-side input terminal of said one switched capacitor step-down circuit and a high voltage-side input terminal of said other switched capacitor step-down circuit are connected to the other of the two input terminals of said power supply unit.

21. The LED lamp device according to claim 20, wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form.

22. The LED lamp device according to claim 21, wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board.

23. The LED lamp device according to claim 22, wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current having a frequency of not lower than 100 Hz.

24. An LED lamp device comprising:

a power supply unit supplied with an alternating-current power supply voltage; and

an LED lamp including one or a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein said power supply unit is operable to obtain a rectified wave of the alternating-current power supply voltage, admit electric power for only part of a time period in which a voltage of the rectified wave corresponding to each half period of a wave of the alternating-current power supply voltage is higher than or equal to a predetermined value, and use the electric power as power for lighting said LED lamp,

wherein said power supply unit is mounted on a flexible printed circuit board, said flexible printed circuit board having a generally S-shaped form,

wherein said power supply unit has terminals attached to opposite sides of the generally S-shaped form of said flexible printed circuit board and has two AC input terminals attached to opposite surfaces of said flexible printed circuit board,

wherein said power supply unit is operable to generate a pulsed current having a peak current value higher than a set average current value, and

wherein the pulsed current has a frequency of not lower than 100 Hz.

25. An LED lamp device comprising:

a power supply unit capable of being supplied with alternating-current or direct-current power; and

an LED lamp including a plurality of serially connected LEDs connected to output terminals of said power supply unit,

wherein a Zener diode is connected in parallel with said one or plurality of LEDs,

wherein a constant-current element is connected to said output terminals of said power supply unit in series with said plurality of LED lamps, and

wherein said Zener diode has a Zener voltage higher than a forward voltage drop of said LED lamps connected in parallel with said Zener diode within a range of from 10% to 30% both inclusive.