TRIAC-Dimmed LED Bleeder Circuit Control for Holding Current

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Solution Overview

Problem

The existing LED lighting systems with TRIAC dimmers face inefficiencies due to high power consumption by the bleeder unit, which affects the operation efficiency and can lead to malfunction if the current falls below a holding current.

Innovation Solution

A high-efficiency TRIAC dimmer switch control system is introduced, comprising a constant current control unit, a bleeder unit, and a bleeder control unit, which dynamically controls the bleeder circuit by generating control signals based on sensing signals to minimize unnecessary power loss and maintain normal operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bleeder unit operates continuously to maintain TRIAC dimmer operation, then the reliability of the dimmer is improved, but the power consumption increases

Engineering Contradiction:

ImproveTRIAC dimmer operation reliabilityVSAvoidbleeder unit power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The bleeder unit is controlled to operate periodically rather than continuously. The control system monitors the LED current and activates the bleeder unit only when the current falls below a predetermined threshold level, thereby maintaining TRIAC dimmer reliability while minimizing unnecessary power consumption during periods when sufficient current is already present.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system employs a feedback mechanism where the control unit continuously monitors the current through the LED and adjusts the bleeder unit operation accordingly. When the monitored current drops below the threshold, the bleeder unit is activated to maintain proper TRIAC dimmer operation, and when current is sufficient, the bleeder unit is deactivated to reduce power consumption.

Inventive Principle:

Principle #23Feedback

2Reliability

If the bleeder current is increased to ensure TRIAC dimmer holds properly, then the dimmer malfunction risk is reduced, but the system efficiency decreases

Engineering Contradiction:

ImproveTRIAC dimmer holding current marginVSAvoidsystem efficiency

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The bleeder current is made dynamic rather than fixed. The control system adjusts the bleeder unit operation in real-time based on the actual LED current conditions, activating it only when necessary to maintain proper TRIAC holding current. This dynamic approach ensures reliable dimmer operation while minimizing energy loss by avoiding continuous high current flow through the bleeder.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11206015B2Switch control systems for light emitting diodes and methods thereof

Publication Date: 2021.12.21 ON BRIGHT INTEGRATIONS CO INC

AI summary

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.