US 12,438,534 B2
Switch control systems for light emitting diodes and methods thereof
Liqiang Zhu, Shanghai (CN); and Jun Zhou, Shanghai (CN)
Assigned to On-Bright Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed by ON-BRIGHT ELECTRONICS (SHANGHAI) CO., LTD., Shanghai (CN)
Filed on Aug. 28, 2023, as Appl. No. 18/238,990.
Application 17/503,238 is a division of application No. 16/809,405, filed on Mar. 4, 2020, granted, now 11,183,996, issued on Nov. 23, 2021.
Application 18/238,990 is a continuation of application No. 17/503,238, filed on Oct. 15, 2021, granted, now 11,784,638.
Application 16/809,405 is a continuation of application No. 16/124,739, filed on Sep. 7, 2018, granted, now 11,201,612, issued on Dec. 14, 2021.
Claims priority of application No. 201710557179.4 (CN), filed on Jul. 10, 2017.
Prior Publication US 2024/0097665 A1, Mar. 21, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H05B 45/395 (2020.01); H03K 5/24 (2006.01); H05B 45/10 (2020.01); H05B 45/3575 (2020.01); G01R 19/165 (2006.01)
CPC H03K 5/24 (2013.01) [H05B 45/10 (2020.01); H05B 45/3575 (2020.01); H05B 45/395 (2020.01); G01R 19/16538 (2013.01); Y02B 20/30 (2013.01)] 9 Claims
OG exemplary drawing
 
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 controller configured to:
receive a sensing voltage indicating a magnitude of a first current flowing through the one or more light emitting diodes;
receive an input voltage generated by a voltage divider, the voltage divider being configured to receive a dimmer output voltage generated by a TRIAC dimmer, the input voltage indicating a magnitude of the dimmer output 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 voltage 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;
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.