Constant Current Control Device for LED Backlight
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Solution Overview
Problem
Existing technologies face challenges in precisely controlling the current flowing through LEDs, especially when used as a backlight source for displays, requiring a simple circuit structure to ensure stable and equalized currents for desirable display effects.
Innovation Solution
A constant current control device comprising a constant current control module, a switched-mode power supply module, and feedback units that work together to maintain a constant current through the load by providing a reference current and adjusting voltage, utilizing MOS transistors and operational amplifiers to regulate the current and voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple circuit structure is used to control current through LEDs, then the circuit complexity is reduced, but the precision of current control deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the voltage across the constant current control unit is detected and fed back to the constant current control circuit. This feedback loop enables the circuit to automatically adjust and maintain precise current control through the LED load without requiring complex external control systems.
Solution Approach 2:
The patent introduces a voltage detection unit and a feedback unit as intermediary components between the power supply module and the load. These intermediaries enable precise current control by measuring voltage and providing feedback signals, achieving accurate control while maintaining a relatively simple overall circuit structure.
2Manufacturing precision
If precise current control is achieved through LEDs, then the display quality is improved, but the circuit structure becomes more complex
Solution Approach 1:
The constant current control unit in the patent performs multiple functions: it acts as both a power regulation element and a feedback signal source. By integrating these functions into a single unit, the circuit achieves precise current equalization across multiple LED chips without requiring separate complex control circuits for each LED.
Solution Approach 2:
The patent combines the voltage detection function and current control function into an integrated constant current control unit. This merging of functions reduces the overall circuit complexity while maintaining precise current control capability, as the same unit both regulates current and provides feedback for regulation.
3Measurement precision
If a feedback mechanism is added to maintain constant voltage, then the current control precision is improved, but the device complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the voltage across the constant current control unit is detected and fed back to the constant current control circuit. This feedback loop enables the circuit to automatically adjust and maintain precise current control through the LED load without requiring complex external control systems.
Data Source
AI summary
The invention provides a constant current control device and a television including the constant current control device. The constant current control device includes a constant current control module and a switched-mode power supply module used for providing a stable voltage for a load. The constant current control module includes a constant current source unit used for providing a reference current, a constant current control unit used for keeping a current flowing through the load constant as the reference current, and a feedback unit used for keeping the voltage of the constant current control unit constant. The present invention, with a simple circuit structure, implements the objective of precisely controlling a current passing through a load.