SWITCH CONTROL SYSTEMS FOR LIGHT EMITTING DIODES AND METHODS THEREOF

• US 20190124736A1
• Filed: 09/07/2018
• Published: 04/25/2019
• Est. Priority Date: 07/10/2017
• Status: Active Grant

• Current Assignee: On-Bright Electronics (Shanghai) Co., Ltd. (Orthosie Investment Holdings Ltd.)
• Original Assignee: On-Bright Electronics (Shanghai) Co., Ltd. (Orthosie Investment Holdings Ltd.)
• Inventors: ZHU, LIQIANG, ZHOU, JUN
• Granted Patent: US 11,201,612 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 19/16538 in AC or DC supplies G01R19/16519 and G01R19/16528 take precedence
• CPC Class Codes: H03K 5/24 the characteristic being amplitude
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/3575 by means of dummy loads or bleeder circuits, e.g. for dimmers
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.

Claims

1. A system for controlling one or more light emitting diodes, the system comprising:

a current generator configured to generate a first current flowing through one or more light emitting diodes, the one or more light emitting diodes being configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer;

a bleeder configured to receive the rectified voltage; and

a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder, the sensing voltage indicating a magnitude of the first current;

wherein the controller is further configured to;

generate the control signal to turn off the bleeder if the sensing voltage satisfies a first condition so that the bleeder does not generate a second current, the second current being larger than zero in magnitude; and

generate the control signal to turn on the bleeder if the sensing signal satisfies a second condition so that the bleeder generates the second current;

wherein the second condition is different from the first condition.

2. The system of claim 1 wherein

the first condition is the sensing voltage being larger than a reference voltage in magnitude;

and

the second condition is the sensing voltage being smaller than the reference voltage in magnitude.

3. The system of claim 1 wherein:

the controller includes a comparator configured to receive the sensing voltage and a reference voltage; and

the controller is further configured to change the control signal to turn off the bleeder in response to the sensing voltage becoming larger than the reference voltage in magnitude.

4. The system of claim 3 wherein the controller is further configured to change the control signal to turn on the bleeder in response to the sensing voltage becoming smaller than the reference voltage in magnitude.

5. The system of claim 4 wherein the controller is further configured to change the control signal to turn on the bleeder, without a delay, in response to the sensing voltage becoming smaller than the reference voltage in magnitude.

6. The system of claim 4 wherein the controller is further configured to change the control signal to turn on the bleeder, with a delay, in response to the sensing voltage becoming smaller than the reference voltage in magnitude.

7. The system of claim 6 wherein the delay is a predetermined time duration.

8. The system of claim 6 wherein the delay is not a predetermined time duration.

9. The system of claim 1 wherein the controller is further configured to:

generate the control signal at a first logic level from a first time to a second time, during which the sensing voltage is smaller than a reference voltage in magnitude;

generate the control signal at a second logic level from the second time to a third time, during which the sensing voltage is larger than the reference voltage in magnitude; and

generate the control signal at the first logic level from the third time to a fourth time, during which the sensing voltage is smaller than the reference voltage in magnitude;

wherein the first logic level and the second logic level are different.

10. The system of claim 9 wherein:

the control signal at the first logic level is configured to turn on the bleeder so that the bleeder generates the second current; and

the control signal at the second logic level is configured to turn off the bleeder so that the bleeder does not generate the second current.

11. The system of claim 1 wherein:

the controller includes a comparator configured to receive the sensing voltage and a reference voltage and generate a comparison signal based at least in part on the sensing voltage and the reference voltage; and

a control signal generator configured to receive the comparison and generate the control signal based at least in part on the comparison signal.

12. The system of claim 11 wherein the control signal generator is further configured to change the control signal to turn on the bleeder, with a predetermined delay, in response to the sensing voltage becoming smaller than the reference voltage in magnitude.

13. The system of claim 12 wherein the controller is further configured to:

generate the control signal at a first logic level from a first time to a second time, during which the sensing voltage is smaller than the reference voltage in magnitude;

generate the control signal at a second logic level from the second time to a third time, during which the sensing voltage is larger than the reference voltage in magnitude;

generate the control signal at the second logic level from the third time to a fourth time, during which the sensing voltage is smaller than the reference voltage in magnitude; and

generate the control signal at the first logic level from the fourth time to a fifth time, during which the sensing voltage is smaller than the reference voltage in magnitude;

wherein;

the first logic level and the second logic level are different; and

a time duration from the third time to the fourth time is equal to the predetermined delay in magnitude.

14. The system of claim 1 wherein the rectifying bridge is coupled to the TRIAC dimmer through a fuse.

15. A system for controlling one or more light emitting diodes, the system comprising:

a current generator configured to generate a first current flowing through one or more light emitting diodes, the one or more light emitting diodes being configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer;

a bleeder configured to receive the rectified voltage; and

a controller configured to;

receive a sensing voltage from the current generator, the sensing voltage indicating a magnitude of the first current;

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; and

output a control signal to the bleeder;

wherein the controller is further configured to;

generate the control signal to turn off the bleeder if the sensing voltage and the input voltage satisfy a first condition so that the bleeder does not generate a second current, the second current being larger than zero in magnitude; and

generate the control signal to turn on the bleeder if the sensing signal and the input voltage satisfy a second condition so that the bleeder generates the second current;

wherein the second condition is different from the first condition.

16. The system of claim 15 wherein the voltage divider includes multiple resistors connected in series and biased between the rectified voltage and a ground voltage.

17. The system of claim 15 wherein the controller is further configured to:

generate the control signal at a first logic level from a first time to a second time, during which the sensing voltage is smaller than a first reference voltage in magnitude and the input voltage is smaller than a second reference voltage in magnitude;

generate the control signal at a second logic level from the second time to a third time, during which the sensing voltage is larger than the first reference voltage in magnitude and the input voltage is larger than the second reference voltage in magnitude;

generate the control signal at the second logic level from the third time to a fourth time, during which the sensing voltage is smaller than the first reference voltage in magnitude and the input voltage is larger than the second reference voltage in magnitude; and

generate the control signal at the first logic level from the fourth time to a fifth time, during which the sensing voltage is smaller than the first reference voltage in magnitude and the input voltage is smaller than the second reference voltage in magnitude;

wherein the first logic level and the second logic level are different.

18. The system of claim 17 wherein the controller is further configured to:

the control signal at the first logic level is configured to turn on the bleeder so that the bleeder generates the second current; and

the control signal at the second logic level is configured to turn off the bleeder so that the bleeder does not generate the second current.

19. The system of claim 15 wherein the rectifying bridge is coupled to the TRIAC dimmer through a fuse.

20-31. -31. (canceled)

32. A method for controlling one or more light emitting diodes, the method comprising:

generating a first current flowing through one or more light emitting diodes, the one or more light emitting diodes being configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer;

receiving the rectified voltage;

receiving a sensing voltage, the sensing voltage indicating a magnitude of the first current; and

outputting a control signal to a bleeder;

wherein the outputting a control signal to a bleeder includes;

generating the control signal to turn off the bleeder if the sensing voltage satisfies a first condition so that the bleeder does not generate a second current, the second current being larger than zero in magnitude; and

generating the control signal to turn on the bleeder if the sensing signal satisfies a second condition so that the bleeder generates the second current;

wherein the second condition is different from the first condition.

33. A method for controlling one or more light emitting diodes, the method comprising:

generating a first current flowing through one or more light emitting diodes, the one or more light emitting diodes being configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer;

receiving a sensing voltage, the sensing voltage indicating a magnitude of the first current;

receiving an input voltage, the input voltage indicating a magnitude of the rectified voltage; and

outputting a control signal to the bleeder;

wherein the outputting a control signal to the bleeder includes;

generating the control signal to turn off the bleeder if the sensing voltage and the input voltage satisfy a first condition so that the bleeder does not generate a second current, the second current being larger than zero in magnitude; and

generating the control signal to turn on the bleeder if the sensing signal and the input voltage satisfy a second condition so that the bleeder generates the second current;

wherein the second condition is different from the first condition.

34-36. -36. (canceled)