LED DRIVER AND DRIVING METHOD

• US 20160212819A1
• Filed: 08/06/2014
• Published: 07/21/2016
• Est. Priority Date: 08/19/2013
• Status: Abandoned Application

• Current Assignee: Philips Lighting Holding BV (Signify N.V.)
• Original Assignee: Philips Lighting Holding BV (Signify N.V.)
• Inventors: EBERSON, ETIENNE NICHOLAAS KATHALIJNTJE PAULUS MARIE, JACOBS, JOSEPH HENDRIK ANNA MARIA, KALKSCHMIDT, CHRISTIAN
• Application Number:
  US14/913,117
• Publication Number:
  US 20160212819A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits

Abstract

An LED driver uses a current setting passive component to set an operating current, and also uses a voltage setting passive component to derive an acceptable voltage range. A current driver is then controlled to deliver the current setting and monitor that a voltage being provided is within the acceptable voltage range.

Claims

1. An LED driver, comprising:

a current setting input for connection to a current setting passive component;

a voltage setting input for connection to a voltage or power setting passive component;

a measuring circuit for measuring a characteristic value of the current setting passive component and a characteristic value of the voltage or power setting passive component;

a controller; and

a current driver,

wherein the controller is adapted to;

derive a current setting for the current driver from the current setting characteristic value;

derive an acceptable voltage or power range from the voltage or power setting characteristic value; and

control the current driver to deliver the current setting and monitor the output voltage or power to determine whether or not it falls within the acceptable range.

2. An LED driver as claimed in claim 1, wherein the driver comprises an operating window driver having a current-voltage operating window.

3. An LED driver as claimed in claim 2, wherein the acceptable voltage/power range comprises upper and lower boundaries, wherein at most one of the upper and lower boundaries is on the edge of the current-voltage window.

4. An LED driver as claimed in claim 1, further comprising a look up table or algorithm for deriving a current setting from the current setting characteristic value.

5. An LED driver as claimed in any preceding claim, wherein the controller is adapted to derive the acceptable voltage or power range from the voltage setting characteristic value by applying a first equation to derive the lower boundary and by applying a second equation to derive the upper boundary.

6. An LED driver as claimed in claim 5, wherein the controller is adapted to derive a nominal operating voltage or power value from the voltage or power setting characteristic value by applying a third equation.

7. An LED driver arrangement, comprising:

an LED driver as claimed in any preceding claim;

a current setting passive component for connection to the current setting input;

a voltage or power setting passive component for connection to the voltage or power setting input.

8. An LED driver arrangement as claimed in claim 7, wherein the current setting passive component and the voltage or power setting passive component are accessible post manufacture of the LED driver.

9. A lighting system comprising:

an LED driver arrangement as claimed in claim 7 and

an LED unit powered by the LED driver,

wherein the current setting passive component has a characteristic value which is used by the LED driver to determine the current level to provide to the LED unit, and the voltage or power setting passive component has a characteristic value which is used by the LED driver to determine the acceptable voltage or power range.

10. A method of driving an LED using a current driver, comprising:

measuring a characteristic value of a current setting passive component;

measuring a characteristic value of a voltage or power setting passive component;

deriving a current setting for the current driver from the current setting characteristic value;

deriving an acceptable voltage or power range from the voltage or power setting characteristic value; and

controlling the current driver to deliver the current setting; and

monitoring the output voltage or power to determine whether or not it falls within the acceptable range.

11. A method as claimed in claim 10, wherein the driver comprises an operating window driver having a current-voltage operating window.

12. A method as claimed in claim 11, wherein the acceptable voltage or power range comprises upper and lower boundaries, wherein at most one of the upper and lower boundaries is on the edge of the current-voltage window.

13. A method as claimed in claim 10, further comprising deriving a nominal operating voltage or power value from the voltage or power setting characteristic value.

14. A method as claimed in claim 10, comprising deriving a current setting from the current setting characteristic value using a look up table or algorithm.

15. A method as claimed in claim 10, comprising deriving the acceptable voltage or power range from the voltage or power setting characteristic value by applying a first equation to derive the lower boundary and by applying a second equation to derive the upper boundary.