Driver and Lighting Module

• US 20190313492A1
• Filed: 04/08/2019
• Published: 10/10/2019
• Est. Priority Date: 04/08/2018
• Status: Active Grant

• Current Assignee: LEDVANCE GmbH (MLS Co. Ltd.)
• Original Assignee: LEDVANCE GmbH (MLS Co. Ltd.)
• Inventors: DING, ShiYu
• Granted Patent: US 11,051,380 B2
• Time in Patent Office: Days
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A driver for a lighting module has driver inputs for receiving a supply voltage from an electronic control gear (ECG) and driver outputs for supplying power to the light-emitting element. The driver also has a ring choke converter (RCC) control circuit with a power switching transistor and with a transformer for supplying power to the driver outputs. The power switching transistor is adapted to control power supplied to the transformer. Coupled to the RCC control circuit, the driver furthermore has a feedback circuit. The feedback circuit is adapted to stabilize the power provided to the light-emitting element.

Claims

1. A driver for a lighting module, comprising:

a plurality of driver inputs connected to an electronic control gear and receiving a supply voltage therefrom;

a plurality of driver outputs with connectors for engaging a light-emitting element and providing power thereto;

a ring choke converter control circuit comprising a power switching transistor and a transformer, the ring choke converter control circuit connected to the plurality of driver outputs, wherein the power switching transistor is adapted to control power supplied to the transformer; and

a feedback circuit coupled to the ring choke converter control circuit and at least one of the driver outputs, wherein the feedback circuit is adapted to stabilize the power provided to the light-emitting element.

2. The driver according to claim 1, wherein the feedback circuit is further adapted to prevent an increase in the power supplied to at least one of the driver outputs when the power supplied by the power switching transistor to the transformer increases when the driver is operated at an increased operating temperature.

3. The driver according to claim 1, wherein the ring choke converter control circuit further comprises a conduction limiting transistor coupled to the power switching transistor and wherein the feedback circuit further comprises a feedback transistor coupled to a base of the conduction limiting transistor;

characterized in that a current through the plurality of driver outputs which exceeds a threshold causes the feedback transistor to reduce an impedance applied to the base of the conduction limiting transistor, which in turn reduces the conduction time of the power switching transistor.

4. The driver according to claim 3, wherein the current delivered to the driver outputs is measured as a voltage over a feedback-control resistor, and applied to a base of the feedback transistor.

5. The driver according to claim 4, wherein the feedback-control resistor is provided in the feedback circuit.

6. The driver according to claim 3, wherein one of the conduction limiting transistor or the feedback transistor is implemented as a bipolar junction transistor.

7. The driver according to claim 6, wherein the transistors used to implement the conduction limiting transistor and the feedback transistor have the same polarity.

8. The driver according to claim 1, wherein the power switching transistor is implemented as a MOSFET.

9. The driver according to claim 1, further comprising a bridge for receiving the supply voltage from the driver inputs and supplying rectified power to the ring choke converter control circuit.

10. A lighting module comprising the driver according to claim 1 and the light-emitting element, wherein the light-emitting element is coupled to the plurality of driver outputs of the driver.

11. The lighting module according to claim 10, wherein the light-emitting element is an LED.