Variable Power Dimming Control Circuit for LED Drivers

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional LED driver circuits with TRIAC switches face issues of unnecessary power consumption and reduced efficiency due to continuous holding current supply, especially when the LED brightness is increased, leading to abnormal TRIAC operation and excessive heat production.

Innovation Solution

A variable power dimming control circuit that detects input voltage and adjusts or stops the holding current supply using a simple detection circuit, comprising a dimming unit, rectification unit, driving unit, and control unit with a detector, controller, and current limiter to maintain a constant driving current, reducing power consumption and heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the holding current is continuously supplied to stabilize the TRIAC operation, then the operating quality of the TRIAC is improved, but the power consumption of the circuit increases and heat production increases

Engineering Contradiction:

Improveoperating quality of TRIACVSAvoidpower consumption of circuit

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies the dynamics principle by making the holding current supply dynamic rather than static. The control circuit dynamically adjusts the holding current based on LED brightness level: supplying holding current when LED brightness is low (to stabilize TRIAC) and stopping holding current when LED brightness is high (to reduce power consumption). This dynamic adaptation resolves the contradiction between maintaining TRIAC stability and reducing power consumption.

Inventive Principle:

Principle #15Dynamics

2Illumination intensity

If the conduction angle of input power is reduced to dim the LED, then the brightness of LED is reduced, but the TRIAC cannot operate normally due to insufficient operating voltage

Engineering Contradiction:

Improvebrightness of LEDVSAvoidnormal operation of TRIAC

Core Design Contradiction:

Illumination intensityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by introducing a holding current that counteracts the insufficient operating voltage condition. When the LED is dimmed to low brightness (small conduction angle), the holding current is supplied to the TRIAC to maintain its operating voltage above the threshold required for normal operation, thereby preventing TRIAC malfunction that would otherwise occur due to voltage insufficiency.

Inventive Principle:

Principle #9Preliminary anti-action

3Adaptability or versatility

If the holding current is supplied to expand the dimming range, then the dimming stability is improved, but the power conversion efficiency of the circuit decreases

Engineering Contradiction:

Improvedimming rangeVSAvoidpower conversion efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent applies periodic action by making the holding current supply conditional and intermittent rather than continuous. The holding current is supplied only during specific periods when the LED brightness is low (below a threshold), and stopped during periods when LED brightness is high. This periodic/conditional supply pattern maintains dimming stability and expands dimming range while minimizing energy loss by avoiding unnecessary holding current during high-brightness operation.

Inventive Principle:

Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution improves dimming stability, reduces unnecessary power consumption, and enhances the operating quality of the LED driver circuit by dynamically controlling the holding current, ensuring normal TRIAC operation and efficient heat dissipation.

Implementation Method 1

detects the magnitude of an input voltage power to timely output or stop outputting a basic voltage power

Methodology Applied

Scientific EffectVoltage detection:

Implementation Method 2

rectifies the power to produce an input voltage (Vin) and an input current (Iin)

Methodology Applied

Scientific EffectRectification:

Implementation Method 3

receiving the input current to generate a holding current

Methodology Applied

Scientific EffectCurrent generation:

Implementation Method 4

supplying a driving current to the LEDs

Methodology Applied

Scientific EffectLight emission from LED: Light Emitting Diode

Implementation Method 5

light emitting diode (LED)

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS8941328B2Variable power dimming control circuit

Publication Date: 2015.01.27 ENNOSTAR CORP

AI summary

Disclosed is a variable power dimming control circuit for driving and linearly adjusting the illumination brightness of a plurality of light emitting diodes (LEDs), and the circuit includes a dimming stabilization unit and a control unit. The control unit is provided for detecting an input current of a circuit, and the dimming stabilization unit is driven for outputting a holding current when the input power is smaller than a standard, and stopping the output the holding current when the input power is greater than the standard. When the LEDs are dimmed to low luminance, a chip controls the operation of the dimming stabilization unit to assure the stability of the dimming operation of a TRIAC. When the LEDs are adjusted to high or full brightness, the chip stops the output of the holding current to reduce unnecessary power consumption and enhance the overall circuit performance effectively.