Resonant power led control circuit with brightness and color control

• US 20070080652A1
• Filed: 10/05/2004
• Published: 04/12/2007
• Est. Priority Date: 11/13/2003
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Lurkens, Peter, Elferich, Reinhold
• Granted Patent: US 7,573,729 B2
• Time in Patent Office: Days
• US Class Current: 315/291
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: H05B 45/39 Circuits containing inverter bridges
• CPC Class Codes: H05B 45/42 Antiparallel configurations
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

The invention relates to a resonant power LED control circuit for the independent, simultaneous brightness and color or color temperature control of two LEDs (41, 42) or two groups of LEDs, comprising a single resonant converter which is essentially formed from a half or full bridge DC/AC converter (2) with a control unit (21), a resonant capacitor, and a transformer (3).

Claims

1. A resonant power LED control which comprises a single resonant converter for the simultaneous, independent brightness and color control of two LEDs (41, 42) or two groups of LEDs, which converter is formed substantially from a half or full bridge DC/AC converter (2) with a control unit (21), a resonant capacitor, and a transformer (3).

2. A resonant power LED control as claimed in claim 1, characterized in that the light emitted by the diodes (41, 42) forms an input value for the control unit (21).

3. A resonant power LED control as claimed in claim 2, characterized in that the input signal representing the input value is achieved by means of an optical coupling, via which coupling the measured output currents of the light emitted by the diodes (41, 42) are fed back to the DC/AC converter (2).

4. A resonant power LED control as claimed in claim 1, characterized in that several LEDs are joined together into groups of arrays connected in series each time.

5. A resonant power LED control as claimed in claim 1, characterized in that the voltage supply of the LEDs (41, 42) takes place via the secondary side of the transformer (3).

6. A resonant power LED control as claimed in claim 1, characterized in that the transformer (3) has a secondary winding to which the LEDs (41, 42) are connected in antiparallel.

7. A resonant power LED control as claimed in claim 1, characterized in that the transformer (3) has two secondary windings to which the LEDs (41, 42) are connected such that they are supplied with current in succession.

8. A resonant power LED control as claimed in claim 7, characterized in that the transformer (3) has a central tap (33) at the secondary side, to which tap the common anode or cathode of the LEDs (41, 42) is connected.

9. A resonant power LED control as claimed in claim 8, characterized in that a further LED (43) is connected as a main light source between the central tap (33) and the common cathode or anode of the LEDs (41, 42) that serve as subsidiary light sources.

10. A resonant power LED control as claimed in claim 9, characterized in that a switching diode is used instead of one of the subsidiary light source LEDs (41, 42).

11. A resonant power LED control as claimed in claim 6, characterized in that the color of the LEDs (41) is white and of the LEDs (42) amber/orange.

12. A resonant power LED control as claimed in claim 9, characterized in that the color of the subsidiary light source LEDs (41) is green, of the subsidiary light source LEDs (42) blue/cyan, and of the main light source LEDs (43) red.

13. A resonant power LED control as claimed in claim 10, characterized in that the color of the subsidiary light source LEDs (41, 42) is cyan/blue and of the main light source LEDs (43) amber/orange.

14. A resonant power LED control as claimed in claim 1, characterized in that the LEDs (41, 42) are connected to filter capacitors (61, 62).