Power converter for an LED assembly and lighting application
View Patent ↗A power converter for an LED assembly includes a switched mode power supply arranged to power the LED assembly, an AC/DC converter arranged to provide a DC supply voltage to the switched mode power supply, and a control unit arranged to receive an input signal representing a required load voltage for powering the LED assembly. The control unit is arranged to control the AC/DC converter based on the input signal.
1. A power converter for an LED assembly, the power converter comprising:
a switched mode power supply arranged to power the LED assembly;
an AC/DC converter arranged to provide a variable DC supply voltage to an input terminal of the switched mode power supply, the switched mode power supply being configured to convert the variable DC supply voltage to a required load voltage for powering the LED assembly; and
a control unit, in normal use for powering the LED assembly, arranged to substantially continuously receive an input signal representing a required load voltage for powering the LED assembly, the control unit being arranged to control the AC/DC converter, thereby, in normal use controlling the variable DC supply voltage, in accordance with the required load voltage.
2. The power converter according to claim 1 , wherein the required load voltage is derived from an output signal of a sensor of the power converter.
3. The power converter according to claim 1 , wherein the required load voltage is derived from an output signal of a sensor of the LED assembly.
4. The power converter according to claim 2 , wherein the input signal comprises the output signal of the sensor.
5. The power converter according to claim 3 , wherein the input signal comprises the output signal of the sensor.
6. The power converter according to claim 1 wherein the control unit is arranged to control the AC/DC converter to provide the variable DC supply voltage at a level substantially matching or proportional to the required load voltage.
7. A lighting application comprising:
a power converter according to claim 1 ; and
an LED assembly arranged to, in use, being powered by the switched mode power supply of the power converter, the LED assembly further comprising a sensor configured to provide an output signal representative of the required load voltage.
8. The lighting application according to claim 7 wherein the input signal comprises the output signal of the sensor.
9. The lighting application according to claim 7 , wherein the control unit is further arranged to control a current, in use, provided by the switched mode power supply to the LED assembly.
10. The lighting application according to claim 7 , wherein the LED assembly comprises a chain of multiple LED units in series, each LED unit being provided with a parallel switching element that is controlled by the control unit.
11. The power converter according to claim 1 , wherein the input signal comprises a measured forward voltage of the LED assembly.
12. The power converter according to claim 1 , wherein the input signal comprise a set-point for a desired output characteristic of the LED assembly.
13. The power converter according to claim 12 , wherein the required load voltage is determined in advance.
14. The power converter according to claim 13 , wherein the control unit is arranged to adjust the DC supply voltage for the switched mode power supply on either a comparatively large time scale and/or on a comparatively small time scale.
15. A lighting application comprising a power converter according to claim 1 and an LED assembly arranged to, in use, being powered by the switched mode power supply of the power converter, wherein the LED assembly comprises a chain of multiple LED units in series, each LED unit being provided with a parallel switching element that is controlled by the control unit.
16. The lighting application according to claim 15 , wherein the input signal comprises a measured forward voltage of the LED assembly.
17. The lighting application according to claim 15 , wherein the input signal comprise a set-point for a desired output characteristic of the LED assembly.
18. The lighting application according to claim 15 , wherein the required load voltage is determined in advance.
19. The lighting application according to claim 18 , wherein the control unit is arranged to adjust the DC supply voltage for the switched mode power supply on either a comparatively large time scale and/or on a comparatively small time scale.