LED Color and Brightness Control via Merged MOSFET Drive
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Solution Overview
Problem
Conventional RGB LED control systems are complex and expensive, lacking design flexibility and reliability, due to partition and bundling control schemes that separately control brightness and color, leading to inefficiencies.
Innovation Solution
A light-emitting diode (LED) color and brightness control apparatus and method using a bandgap voltage reference, MOSFET devices, and a control circuit to generate gate drive signals for controlling current flow based on predetermined color and brightness levels, incorporating a current mirror and operational amplifiers to adjust current through LED channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If partition control scheme or bundling control scheme is used to control color and brightness of RGB LED system, then color and brightness control is achieved, but system complexity increases and reliability decreases
Solution Approach 1:
The patent merges the control of color and brightness into a single integrated control mechanism. Instead of using separate control schemes for color and brightness (partition control) or bundling them together (bundling control), the invention combines both control functions into one unified system that simultaneously manages color mixing and brightness adjustment through a single control architecture, thereby reducing system complexity while maintaining full control capability
Solution Approach 2:
The control system in the patent is designed with multi-functionality to handle both color and brightness control through a universal control mechanism. The single control apparatus can adaptively manage different control scenarios (color adjustment, brightness adjustment, or both simultaneously) without requiring separate dedicated control circuits, thus reducing overall system complexity while preserving comprehensive control capabilities
2Ease of operation
If partition control scheme or bundling control scheme is used to control color and brightness of RGB LED system, then color and brightness control is achieved, but reliability decreases
Solution Approach 1:
By merging color and brightness control into a single integrated system, the patent reduces the number of independent control paths and potential failure points. The unified control architecture ensures that both color and brightness are managed through coordinated control signals, improving system reliability by eliminating the need for multiple separate control schemes that could independently fail
3Ease of operation
If conventional RGB control methods with partition or bundling control schemes are used, then color and brightness control is achieved, but design flexibility is reduced
Solution Approach 1:
The control system employs dynamic control capabilities that allow it to adaptively adjust between different control modes and parameters. The system can dynamically respond to different operating conditions and control requirements, providing design flexibility by enabling real-time adjustments to color and brightness control strategies without being constrained by fixed control schemes
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 provides a simple and efficient control mechanism that enhances design flexibility, improves reliability, and reduces system complexity while maintaining high channel-to-channel accuracy, achieving precise color and brightness control with reduced costs.
Implementation Method 1
a bandgap voltage reference configured to generate a current reference for controlling a plurality of light emitting diode channels
Implementation Method 2
a plurality of MOSFET devices connected in parallel and coupled between a cathode of a light emitting diode channel and ground, wherein the plurality of MOSFET devices is configured to control a current flowing through the light emitting diode channel
Implementation Method 3
The dimming process can be divided into two categories: analog dimming and PWM (pulse-width modulation) dimming
Implementation Method 4
When a voltage is applied to the LED, a current flows through the LED. In response to the current flowing through the LED, electrons and holes recombine in the PN Junction of the diode. In the recombination process, energy is released in the form of photons.
Data Source
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AI summary
An apparatus includes a plurality of MOSFET device groups connected in parallel, wherein a first common node of the plurality of MOSFET device groups is coupled to a cathode of a light emitting diode channel of a plurality of light emitting diode channels, and a second common node of the plurality of MOSFET device groups is connected to ground, and a control circuit configured to generate gate drive signals for the plurality of MOSFET device groups, wherein the gate drive signals are configured to adjust a current flowing through the light emitting diode channel based on a predetermined color and a predetermined brightness level of the light emitting diode channel, and under different duty cycles, the control circuit is configured to control the current flowing through the light emitting diode channel to be proportional to a corresponding duty cycle.