LED Driving Circuit Current Regulation via Voltage Feedback
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Solution Overview
Problem
Existing LED driving circuits lack precise control over the driving current, which affects the luminance and color consistency of LEDs in backlight applications, necessitating improved current regulation methods.
Innovation Solution
An LED driving circuit incorporating an AC/DC converting circuit, a switching element, a control unit, and resistors and capacitors to detect half-cycle or full-cycle voltage, enabling precise control of the driving current by comparing detected voltage with a set target voltage and adjusting the switching element accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a current switching circuit is used to limit load current within a stable scope, then the load current stability is improved, but the LED driving current precision is insufficient
Solution Approach 1:
The patent implements a feedback mechanism where the control unit detects the actual driving current of the LED and compares it with a target current value. Based on the detection result, the control unit adjusts the switching element to regulate the driving current, forming a closed-loop control system that improves current precision while maintaining stability
Solution Approach 2:
The patent replaces simple mechanical current limiting with an electronic control system that uses voltage detection, signal processing, and electronic switching to achieve precise current regulation. The control unit processes detection signals and generates control signals to replace粗放式的 current limiting
2Illumination intensity
If the driving current of LEDs is controlled through a driving circuit, then the luminance and color consistency is improved, but the device complexity increases
Solution Approach 1:
The control unit performs multiple functions including current detection, signal processing, control signal generation, and switching element control. By integrating these functions into a single control unit, the patent reduces overall system complexity while achieving precise current control for consistent LED luminance and color
Solution Approach 2:
The patent combines the detection circuit, control logic, and switching control into an integrated driving circuit system. The control unit merges multiple control functions to regulate LED current, reducing the need for separate complex control components
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 circuit achieves precise control of the driving current, enhancing the performance and consistency of LED backlighting by accurately regulating the current flow based on detected voltage levels.
Implementation Method 1
an AC/DC converting circuit, a switching element, a control unit, a second resistor, a first capacitor, and a first inductor. The AC/DC converting circuit converts an AC power source into a DC power source
Implementation Method 2
The first inductor includes a first end and a second end, in which the first end of the first inductor is connected to the ground contact and the second end of the first capacitor, and the second end of the first inductor is connected to a load
Data Source
AI summary
A light-emitting diode driving circuit includes an AC/DC converting circuit for converting an AC power source into a DC power source; a switching element having an input contact connected to the AC/DC converting circuit; a control unit for outputting a control signal to the switching element at a set frequency to turn on or turn off the switching element, wherein a first resistor is disposed between a power contact thereof and the input contact of the switching element; a second resistor for enabling the control unit to detect a half-cycle voltage of the DC power source; a capacitor having a first end connected to the power contact, and a second end connected to a ground contact of the control unit; and an inductor having a first end connected to the ground contact and the second end of the capacitor, and a second end connected to a light-emitting diode.