Systems and methods for bleeder control related to lighting emitting diodes

Patent metadata

Field	Value
Publication number	US-10512131-B2
Application number	US-201816129576-A
Country	US
Kind code	B2
Filing date	Sep 12, 2018
Priority date	Sep 14, 2017
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

System and method for controlling one or more light emitting diodes. For example, the system includes a bleeder configured to receive a rectified voltage generated by a rectifying bridge, and a dimmer detector configured to receive an input voltage generated by a voltage divider, determine whether or not the rectified voltage is associated with a TRIAC dimmer, and output a control signal to the bleeder. The voltage divider is configured to receive the rectified voltage, and the input voltage indicates a magnitude of the rectified voltage.

First claim

What is claimed is:

1. A system for controlling one or more light emitting diodes, the system comprising:
a bleeder configured to receive a rectified voltage generated by a rectifying bridge; and
a dimmer detector configured to:
receive an input voltage generated by a voltage divider, the voltage divider being configured to receive the rectified voltage, the input voltage indicating a magnitude of the rectified voltage;
determine whether or not the rectified voltage is associated with a TRIAC dimmer; and
output a control signal to the bleeder;

wherein the dimmer detector is further configured to determine that the rectified voltage is associated with a TRIAC dimmer if a first time duration for the rectified voltage to increase from a first voltage to a second voltage is smaller than a first predetermined duration or a second time duration for the rectified voltage to decrease from the second voltage to the first voltage is smaller than a second predetermined duration;
wherein the dimmer detector is further configured to:
generate the control signal to turn on the bleeder if the rectified voltage is determined to be associated with a TRIAC dimmer so that the bleeder generates a first current, the first current being larger than zero in magnitude; and
generate the control signal to turn off the bleeder if the rectified voltage is determined not to be associated with any TRIAC dimmer so that the bleeder does not generate the first current.

2. The system of claim 1 wherein:
the dimmer detector is further configured to determine that the rectified voltage is associated with a TRIAC dimmer;
the first time duration is larger than the first predetermined duration; and
the second time duration is smaller than the second predetermined duration.

3. The system of claim 1 wherein the dimmer detector is further configured to determine that the rectified voltage is not associated with any TRIAC dimmer if the first time duration is not smaller than the first predetermined duration and the second time duration is not smaller than the second predetermined duration.

4. The system of claim 3 wherein:
the dimmer detector is further configured to determine that the rectified voltage is not associated with any TRIAC dimmer;
the first time duration is larger than the first predetermined duration; and
the second time duration is larger than the second predetermined duration.

5. The system of claim 1 wherein:
the dimmer detector is further configured to determine that the rectified voltage is associated with a TRIAC dimmer;
the first time duration is smaller than the first predetermined duration; and
the second time duration is smaller than the second predetermined duration.

6. The system of claim 1 wherein the voltage divider includes multiple resistors connected in series and biased between the rectified voltage and a ground voltage.

7. The system of claim 1 wherein the dimmer detector is further configured to determine whether or not the first time duration for the rectified voltage to increase from the first voltage to the second voltage is smaller than the first predetermined duration based at least in part on a first change of the input voltage.

8. The system of claim 7 wherein the dimmer detector is further configured to determine whether or not the second time duration for the rectified voltage to decrease from the second voltage to the first voltage is smaller than the second predetermined duration based at least in part on a second change of the input voltage.

9. The system of claim 1 , and further comprising a current generator configured to generate a second current flowing through one or more light emitting diodes, the one or more light emitting diodes being configured to receive the rectified voltage.

10. The system of claim 9 wherein the dimmer detector is further configured to generate the control signal to turn on the bleeder if the rectified voltage is determined to be associated with a TRIAC dimmer so that the bleeder generates the first current to keep a third current flowing though the TRIAC dimmer from becoming smaller than a holding current of the TRIAC dimmer.

11. A method for controlling one or more light emitting diodes, the method comprising:
receiving an input voltage, the input voltage indicating a magnitude of a rectified voltage generated by a rectifying bridge;
determining whether or not the rectified voltage is associated with a TRIAC dimmer; and
outputting a control signal to a bleeder;
wherein the determining whether or not the rectified voltage is associated with a TRIAC dimmer includes:
determining that the rectified voltage is associated with a TRIAC dimmer if a first time duration for the rectified voltage to increase from a first voltage to a second voltage is smaller than a first predetermined duration or a second time duration for the rectified voltage to decrease from the second voltage to the first voltage is smaller than a second predetermined duration;

wherein the outputting a control signal to a bleeder includes:
generating the control signal to turn on the bleeder if the rectified voltage is determined to be associated with a TRIAC dimmer so that the bleeder generates a first current, the first current being larger than zero in magnitude; and
generating the control signal to turn off the bleeder if the rectified voltage is determined not to be associated with any TRIAC dimmer so that the bleeder does not generate the first current.

12. The method of claim 11 wherein the determining whether or not the rectified voltage is associated with a TRIAC dimmer includes:
determining that the rectified voltage is associated with a TRIAC dimmer;
wherein:
the first time duration is larger than the first predetermined duration; and
the second time duration is smaller than the second predetermined duration.

13. The method of claim 11 wherein the determining whether or not the rectified voltage is associated with a TRIAC dimmer includes:
determining that the rectified voltage is not associated with any TRIAC dimmer if the first time duration is not smaller than the first predetermined duration and the second time duration is not smaller than the second predetermined duration.

14. The method of claim 13 wherein the determining whether or not the rectified voltage is associated with a TRIAC dimmer includes:
determining that the rectified voltage is not associated with any TRIAC dimmer;
wherein:
the first time duration is larger than the first predetermined duration; and
the second time duration is larger than the second predetermined duration.

15. The method of claim 11 wherein the determining whether or not the rectified voltage is associated with a TRIAC dimmer includes:
determining that the rectified voltage is associated with a TRIAC dimmer;
wherein:
the first time duration is smaller than the first predetermined duration; and
the second time duration is smaller than the second predetermined duration.

16. The method of claim 11 wherein the determining that the rectified voltage is associated with a TRIAC dimmer if a first time duration for the rectified voltage to increase from a first voltage to a second voltage is smaller than a first predetermined duration or a second time duration for the rectified voltage to decrease from the second voltage to the first voltage is smaller than a second predetermined duration includes:
determining that the first time duration for the rectified voltage to increase from the first voltage to the second voltage is smaller than the first predetermined duration based at least in pa

Assignees

• On Bright Electronics Shanghai Co Ltd

Inventors

• Zhu Liqiang
• Zhou Jun
• Fang Lieyi

Classifications

• H05B45/14

  using electrical feedback from LEDs or from LED modules · CPC title

• H05B45/44

  with an active control inside an LED matrix · CPC title

• H05B45/10 Primary

  Controlling the intensity of the light · CPC title

• H05B33/0842

  Electricity · mapped topic

• H05B33/0809

  Electricity · mapped topic