Systems and methods for bleeder control related to TRIAC dimmers associated with LED lighting

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

• a voltage divider configured to receive a rectified voltage associated with a TRIAC dimmer, the voltage divider being configured to generate a converted voltage proportional to the rectified voltage;
• and
• a bleeder configured to receive a first bleeder control signal and the rectified voltage, the first bleeder control signal indicating whether a bleeder current is allowed or not allowed to be generated;
• wherein:
• the bleeder includes a current controller and a current generator;
• the current controller is configured to receive the first bleeder control signal and generate an input voltage based at least in part on the first bleeder control signal;
• and
• the current generator is configured to receive the rectified voltage and the input voltage and generate the bleeder current based at least in part on the input voltage;
• wherein, if the first bleeder control signal indicates that the bleeder current is not allowed to be generated,
• the current controller is configured to gradually reduce the input voltage from a first voltage magnitude at a first time to a second voltage magnitude at a second time;
• and
• the current generator is configured to gradually reduce the bleeder current from a first current magnitude at the first time to a second current magnitude at the second time;
• wherein the second time follows the first time by a duration of time.

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

• a voltage divider configured to receive a rectified voltage associated with a TRIAC dimmer, the voltage divider being configured to generate a converted voltage proportional to the rectified voltage;
• and
• a bleeder controller configured to receive the converted voltage and a sensing signal associated with a diode current flowing through the one or more light emitting diodes, the bleeder controller being configured to generate a first bleeder control signal based at least in part on the converted voltage, the first bleeder control signal indicating whether a bleeder current is allowed or not allowed to be generated;
• wherein the bleeder controller is configured to:
• determine a phase range within which the TRIAC dimmer is in a conduction state based on at least information associated with the converted voltage;
• and
• generate a detection signal by comparing a predetermined conduction phase threshold and the phase range within which the TRIAC dimmer is in the conduction state;
• wherein the bleeder controller is further configured to:
• if the detection signal indicates that the phase range within which the TRIAC dimmer is in the conduction state is larger than the predetermined conduction phase threshold, generate the first bleeder control signal based at least in part on the sensing signal;
• and
• if the detection signal indicates that the phase range within which the TRIAC dimmer is in the conduction state is determined to be smaller than the predetermined conduction phase threshold, generate the first bleeder control signal based at least in part on the converted voltage.

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

• receiving a first bleeder control signal, the first bleeder control signal indicating whether a bleeder current is allowed or not allowed to be generated;
• generating an input voltage based at least in part on the first bleeder control signal;
• receiving the input voltage and a rectified voltage associated with a TRIAC dimmer;
• and
• generating the bleeder current based at least in part on the input voltage;
• wherein:
• the generating an input voltage based at least in part on the first bleeder control signal includes, if the first bleeder control signal indicates that the bleeder current is not allowed to be generated, gradually reducing the input voltage from a first voltage magnitude at a first time to a second voltage magnitude at a second time;
• and
• the generating the bleeder current based at least in part on the input voltage includes, if the first bleeder control signal indicates that the bleeder current is not allowed to be generated, gradually reducing the bleeder current from a first current magnitude at the first time to a second current magnitude at the second time;
• wherein the second time follows the first time by a duration of time.

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

• receiving a rectified voltage associated with a TRIAC dimmer;
• generating a converted voltage proportional to the rectified voltage;
• outputting the converted voltage;
• receiving a first bleeder control signal that is generated based at least in part on the converted voltage, the first bleeder control signal indicating whether a bleeder current is allowed or not allowed to be generated;
• generating an input voltage based at least in part on the first bleeder control signal;
• receiving the input voltage and the rectified voltage;
• and
• generating the bleeder current based at least in part on the input voltage;
• wherein:
• the generating an input voltage based at least in part on the first bleeder control signal includes, if the first bleeder control signal indicates that the bleeder current is not allowed to be generated, gradually reducing the input voltage from a first voltage magnitude at a first time to a second voltage magnitude at a second time;
• and
• the generating the bleeder current based at least in part on the input voltage includes, if the first bleeder control signal indicates that the bleeder current is not allowed to be generated, gradually reducing the bleeder current from a first current magnitude at the first time to a second current magnitude at the second time;
• wherein the second time follows the first time by a duration of time.

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

• receiving a rectified voltage associated with a TRIAC dimmer;
• generating a converted voltage proportional to the rectified voltage;
• outputting the converted voltage;
• receiving the converted voltage and a sensing signal associated with a diode current flowing through the one or more light emitting diodes;
• generating a first bleeder control signal based at least in part on the converted voltage, the first bleeder control signal indicating whether a bleeder current is allowed or not allowed to be generated;
• and
• outputting the first bleeder control signal;
• wherein the generating a first bleeder control signal based at least in part on the converted voltage includes:
• determining a phase range within which the TRIAC dimmer is in a conduction state based on at least information associated with the converted voltage;
• generating a detection signal by comparing a predetermined conduction phase threshold and the phase range within which the TRIAC dimmer is in the conduction state;
• if the detection signal indicates that the phase range within which the TRIAC dimmer is in the conduction state is larger than the predetermined conduction phase threshold, generating the first bleeder control signal based at least in part on the sensing signal;
• and
• if the detection signal indicates that the phase range within which the TRIAC dimmer is in the conduction state is smaller than the predetermined conduction phase threshold, generating the first bleeder control signal based at least in part on the converted voltage.