Power supply and led lamp device

• US 20020158590A1
• Filed: 07/10/2001
• Published: 10/31/2002
• Est. Priority Date: 12/14/1999
• Status: Active Grant

• Current Assignee: Naoco Incorporated
• Original Assignee: Takion Company Limited
• Inventors: Ota, Tsutomu, Saito, Yutaka, Narukawa, Toshiaki, Ozaki, Kouei
• Granted Patent: US 6,577,072 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• 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 characterized by comprising:

rectified wave acquiring means for obtaining a rectified wave of an alternating-current power supply voltage; and

electric power output means for admitting electric power for only part of a time period in which a voltage of the rectified wave obtained by said rectified wave acquiring means and 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 for outputting the electric power as power for driving a load.

18. The power supply unit according to any one of claims 1 to 3, characterized in that said power supply unit is mounted on a flexible printed circuit board, the flexible printed circuit board being bent into a generally S-shaped form.

20. The power supply unit according to any one of claims 1 to 3, characterized in that said power supply unit generates a pulsed current having a peak current value higher than a set average current value, the pulsed current having a frequency of not lower than 100 Hz.

2. A power supply unit characterized by comprising:

a rectifying diode bridge for obtaining 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 the changeover switches, the changeover switches being switched to either of the two positions by said clock signal control circuit such that the capacitors are charged when the changeover switches are in one of the two positions and that the capacitors are discharged when the changeover switches are in the other of the two positions, thereby supplying electric power to a load.

3. 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, characterized by 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 the two switched capacitor step-down circuits and a low voltage-side input terminal of the other switched capacitor step-down circuit 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.

4. An LED lamp device characterized by 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 obtains a rectified wave of the alternating-current power supply voltage, admits 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 uses the electric power as power for lighting said LED lamp.

5. The LED lamp device according to claim 4, characterized in that said power supply unit includes a rectifying diode bridge and a Zener diode serving as a constant-voltage element and connected in series with the rectifying diode bridge, the diode bridge rectifying the input voltage and then the Zener diode admitting the electric power for only the time period in which the rectified voltage is higher than or equal to the predetermined value, to light said LED lamp.

6. An LED lamp device characterized by comprising:

a power supply unit 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 a Zener diode is connected in parallel with said one or plurality of LEDs.

7. The LED lamp device according to claim 6, characterized in that said LED lamp comprises a plurality of LED lamps, a constant-current element being connected to the output terminals of said power supply unit in series with said plurality of LED lamps.

8. The LED lamp device according to claim 7, characterized in that said Zener diode has a Zener voltage higher than a forward voltage drop of the LED lamp connected in parallel with said Zener diode within a range of from 10% to 30% both inclusive.

9. An LED lamp device characterized by comprising:

a power supply unit 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, the switching circuit being supplied with signals from the current detection circuit and the input voltage detecting section to perform ON/OFF control of the switching element.

10. The LED lamp device according to claim 9, characterized in that said power supply unit obtains a rectified wave of the power supply voltage, admits 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 uses the electric power as power for lighting said LED lamp.

15. The LED lamp device according to any one of claims 4 through 14, characterized in that said power supply unit is mounted on a flexible printed circuit board, the flexible printed circuit board being bent into a generally S-shaped form.

17. The LED lamp device according to any one of claims 4 through 16, characterized in that said power supply unit generates a pulsed current having a peak current value higher than a set average current value, the pulsed current having a frequency of not lower than 100 Hz.

11. An LED lamp device characterized by comprising:

a power supply unit 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, the switching control circuit being supplied with signals from the input/output voltage detecting section and the current detection circuit to perform ON/OFF control of the switching element.

16. The LED lamp device according to claim 15, characterized in that said power supply unit has terminals attached to opposite sides of the generally S-shaped form of the flexible printed circuit board, and has two AC input terminals attached to opposite surfaces of the flexible printed circuit board.

19. The power supply unit according to claim 18, characterized in that said power supply unit has terminals attached to opposite sides of the generally S-shaped form of the flexible printed circuit board, and has two AC input terminals attached to opposite surfaces of the flexible printed circuit board.

12. An LED lamp device characterized by comprising:

a power supply unit 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, the switching circuit being supplied with signals from the current detection circuit and the input voltage detecting section to perform ON/OFF control of the switching element,

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

13. An LED lamp device characterized by comprising:

a power supply unit 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 for obtaining a rectified wave of the power supply voltage, an oscillator circuit, a clock signal control circuit, and a switched capacitor step-down circuit,

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

14. An LED lamp device characterized by comprising:

a power supply unit 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,

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