Drive unit for a lighting element and operating method therefor

Patent metadata

Field	Value
Publication number	US-9648689-B2
Application number	US-201415029722-A
Country	US
Kind code	B2
Filing date	Oct 14, 2014
Priority date	Oct 15, 2013
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

The invention relates to a drive unit for a lighting element and an operating method for such drive unit and to a lighting element including such drive unit. By selectively providing power to a control unit of the drive unit using different voltages at different stages of the overall drive unit, there is an additional degree of freedom which may be used for improving power efficiency, in particular for reducing standby power consumption, while still meeting specific space and cost constraints.

First claim

The invention claimed is:

1. An apparatus including a drive unit for driving a lighting element, the lighting element comprising at least one light source comprising at least one light emitting diode, the drive unit comprising:
a first power converter arranged for receiving input power by drawing at least a part of a predefined current waveshape and for outputting a bus voltage,
a control unit arranged for controlling the drive unit,
a second power converter for providing power to the control unit, the input of the second power converter being coupled at least to the bus voltage,
wherein the drive unit has, under the control of the control unit, an operation mode in which by means of the bus voltage an LED voltage is provided for operating the at least one light emitting diode, and a standby mode in which the LED voltage for operating the at least one light emitting diode is not provided and no lighting is provided by the at least one light emitting diode while power is provided to the control unit,
wherein the control unit is arranged for adjusting a level of the bus voltage outputted by the first power converter from an operation level in the operation mode to a standby level in the standby mode and vice versa.

2. The apparatus of claim 1 , wherein the input of the second power converter is coupled to the first power converter via a switching circuitry, the switching circuitry also coupling the input of the second power converter to a further voltage provided within the drive unit.

3. The apparatus of claim 2 , wherein the switching circuitry is arranged for providing, to the second power converter, the bus voltage during the standby mode and the further voltage the during the operation mode.

4. The apparatus of claim 3 , further comprising a third power converter outputting the LED voltage for powering the at least one light emitting diode, the input of the third power converter being coupled at least to the bus voltage, wherein the further voltage is the LED voltage or another voltage provided by the third power converter.

5. The apparatus of claim 4 , wherein the third power converter comprises a buck circuitry.

6. The apparatus of claim 2 , wherein, during operation mode and standby mode, the switching circuitry is arranged such that the input of the second power converter is electrically connected to the further voltage when the bus voltage is above a predetermined threshold level and is electrically connected to the output of the first power converter when the bus voltage is below the predetermined threshold level.

7. The apparatus of claim 1 , wherein the first power converter is arranged for outputting, during the operation mode and/or the standby mode, the bus voltage being higher than the input voltage.

8. The apparatus of claim 7 , wherein the first power converter comprises a boost circuitry.

9. The apparatus of claim 1 , wherein the second power converter comprises a linear voltage regulator.

10. The apparatus of claim 1 , wherein drive unit is arranged for providing the LED voltage being lower than the bus voltage.

11. The apparatus of claim 1 , wherein the input voltage is 12 V of alternating current, wherein the first power converter includes a bridge rectifier.

12. The apparatus of claim 11 , wherein, at least during operation mode, the bus voltage is in the range of 20 to 28 V of direct current and the LED voltage is in the range of 8 to 16 V of direct current.

13. The apparatus of claim 1 , wherein the control unit is adapted to receive instructions and to control the lighting element in accordance to the instructions.

14. The apparatus of claim 1 , further comprising:
a multifaceted reflector light bulb having a diameter of approximately 51 mm; and
the at least one light source comprising the at least one light emitting diode.

15. A method of operating a drive unit for a lighting element including at least one light emitting diode, such that the lighting element has an operation mode in which the at least one light emitting diode is operated by using a bus voltage, and a standby mode in which the at least one light emitting diode is not operated and no lighting is provided by the at least one light emitting diode while power is provided to a control unit, the method comprising:
receiving an input power by drawing at least a part of a predefined current waveshape,
producing the bus voltage from the received input power,
adjusting a level of the outputted bus voltage upon switching from the operation mode to the standby mode, and,
in the standby mode, converting the bus voltage to an output voltage less than the bus voltage for providing power to the control unit.

16. The method of claim 15 , further comprising:
providing a control signal to the control unit;
in response to the control signal, the control unit outputting to a control circuit a bus reference voltage; and
the control circuit comparing the bus voltage and the bus reference voltage and in response to the comparison outputting a signal to control the control unit to cause the drive unit to switch the lighting element between the operating mode and the standby mode.

17. An apparatus, comprising:
a first power converter configured to receive input power by drawing at least a part of a predefined current waveshape, and to output a bus voltage,
a control unit configured to control the apparatus, in response to at least one control signal, to be selectively in one of: an operation mode wherein the bus voltage has an operation voltage level which is converted to a light emitting diode (LED) voltage for illuminating at least one LED, and a standby mode wherein the bus voltage has a standby voltage level which is less than the operation voltage level and no lighting is provided by the at least one light emitting diode;
a voltage regulator configured to be connected to receive the bus voltage when the apparatus is in the operation mode and to receive a cathode voltage of the LED when the apparatus is in the standby mode, and to supply an output voltage to the control unit in both the operating mode and the standby mode.

18. The apparatus of claim 17 , wherein the control unit is configured to output a bus reference voltage in response to the control signal, wherein the bus reference voltage has a first value in the operating mode and has a second value, different from the first value, in the standby mode, the apparatus further comprising a control circuit configured to receive the bus voltage and the bus reference voltage and in response thereto to cause the bus voltage to have the operating voltage when the bus reference voltage has the first value and to cause the bus voltage to have the standby voltage when the bus reference voltage has the second value.

19. The apparatus of claim 17 , further comprising a switching circuit configured to receive the bus voltage and the cathode voltage, and when the bus voltage is less than a first threshold voltage to supply the bus voltage to the voltage regulator and when the bus voltage is greater than a second voltage to supply the cathode voltage to the cathode voltage to the voltage regulator.

20. The apparatus of claim 17 , wherein the operating voltage level is in a range of 20 VDC to 28 VDC, and the standby voltage level is in a range of 10 VDC to 18 VDC.

Assignees

• Philips Lighting Holding Bv

Inventors

• Liu Junhu
• Radermacher Harald Josef Gunther
• Fu Jie
• Sun Xiao

Classifications

• H05B45/395

  Linear regulators · CPC title

• H05B33/0845 Primary

  Electricity · mapped topic

• H05B33/0812

  Electricity · mapped topic

• H05B33/0815

  Electricity · mapped topic

• H05B45/38 Primary

  using boost topology · CPC title