LIGHTING SYSTEM WITH A PLURALITY OF LEDs

• US 20110210670A1
• Filed: 11/09/2009
• Published: 09/01/2011
• Est. Priority Date: 11/13/2008
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sauerlander, Georg, Willwohl, Harald
• Granted Patent: US 9,801,243 B2
• Time in Patent Office: Days
• US Class Current: 315/120
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices
• CPC Class Codes: H05B 45/54 in a series array of LEDs
• CPC Class Codes: H05B 47/185 via power line carrier transmission
• CPC Class Codes: H05B 47/23 of two or more light sources connected in series
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A lighting system (1) comprises a power unit (20) for producing data-modulated current, and a light unit (10) receiving this current at its input and output terminals (11, 12).

The light unit comprises two or more light modules (100A; 100B; 100C) connected in series.

Each light module comprises:

• • a LED string (110) of one or more LEDs (111, 112, 113) connected between module input and output terminals (101, 102), each LED having an associated controllable shunt switch (121, 122, 123) connected in parallel thereto;
  • a module controller (190) for controlling the shunt switches, the module controller (190) having a input terminals (191, 192) connected to said module input and output terminals, respectively. The module controller demodulates the data and controls the switches on the basis of an action command contained therein, if an address information contained therein matches the unique controller address.

Claims

1. Light module, comprising:

an input terminal;

an output terminal;

a LED string comprising a plurality of LEDs connected between said terminals, each LED having an associated controllable shunt switch connected in parallel thereto;

a module controller for controlling the shunt switch or switches, the module controller having a first input terminal connected to the module input terminal and a second input terminal connected to the module output terminal.

2. Light module according to claim 1, further comprising a diode coupled between an input terminal of the module controller and the corresponding module input or output terminal.

3. Light module according to claim 1, wherein the module controller comprises an energy buffer parallel to its input terminals.

4. Light module according to claim 1, wherein each LED is provided with a respective voltage sensor for measuring the voltage drop over the LED, and wherein the module controller has sensor inputs 194a, 194b, 194c coupled to the voltage sensor for receiving their measuring signals.

5. Light module according to claim 4, wherein the module controller is configured, in response to a measuring signal indicating that at least one LED of the plurality of LEDs has failed, to generate a control signal for the shunt switch associated with said at least one LED to remain closed.

6. Light module according to claim 1, capable of receiving at its input and output terminal an input current with a data signal modulated thereon, the data containing an address and an action command;

wherein the module controller is configured to decode the modulated data, the module controller having a predetermined unique address; and

wherein the module controller is configured to compare the decoded data address with its own address and, if the compared addresses match, to execute the decoded action command.

7. Light module according to claim 1, capable of receiving at its input and output terminal an input current from a power source with a current source;

wherein the module controller is configured to send a data signal to the power source by briefly switching at least one of said shunt switches from a conductive state to a non-conductive state or from a non-conductive state to a conductive state such as to cause modulation of the output voltage of the current source.

8. Light unit, having an input terminal and an output terminal, the light unit comprising a light module implemented in accordance to any of the previous claims, wherein the module input terminal is connected to the unit input terminal and wherein the module output terminal is connected to the unit output terminal.

9. Light unit, having an input terminal and an output terminal, the light unit comprising two or more light modules of claim 1 connected in series, each light module except one having its output terminal connected to the input terminal of the next light module;

wherein the module input terminal of the first light module is connected to the unit input terminal and wherein the module output terminal of the last light module is connected to the unit output terminal.

11. Lighting system, comprising a power unit and a light unit according to claim 8, the power unit comprising a controllable current source and a power controller controlling the current source, the power unit having output terminals of the current source connected to the light unit input and output terminals via power lines, respectively, one of said power lines being implemented by mass.

12. Lighting system according to claim 11, wherein the power unit controller is designed to control the current source such as to modulate the output current with data.

13. Lighting system according to claim 12, wherein data modulation is effected by a series of current interruptions of such frequency and duration as not to affect light output of the LEDs, at least not noticeable for the human eye.

14. Lighting system according to claim 13, wherein said interruptions are effected by the power controller briefly switching OFF the current source.

15. Lighting system according to claim 12, wherein the power controller effects the data coding in a brief data burst having a duration of a few milliseconds.

10. Light unit, having an input terminal and an output terminal and a plurality of LEDs connected in series between said input terminal and output terminal, each LED having an associated controllable shunt switch connected in parallel thereto;

a plurality of controllers for controlling the shunt switches, each module controller having a first input terminal and a second input terminal;

wherein the series arrangement of LEDs has a plurality of intermediate nodes between said input terminal and output terminal;

wherein each node is coupled to a second input terminal of one controller and a first input terminal of the next controller.

16. (canceled)