LED Driver PWM Control for Variable Output Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light emitting diode (LED) driving apparatuses have difficulty in easily adjusting output current, requiring hardware modifications to change the current level.
Innovation Solution
A light emitting diode driving apparatus comprising a user setting unit, a pulse width modulation control unit, and a dimming unit, where the user setting unit sends a signal to the pulse width modulation control unit, which multiplies it with a dimming signal to generate a control signal that adjusts the output current, allowing the LED driving unit to drive the LED with a variable current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If hardware modification is performed to change output current, then output current is changed, but device complexity and ease of operation deteriorate
Solution Approach 1:
The patent replaces hardware modification (mechanical/electrical system change) with a software control system. The microcontroller unit executes control algorithms to adjust output current through pulse width modulation, eliminating the need for physical hardware changes. This substitution resolves the contradiction by enabling easy current adjustment through software while avoiding hardware complexity.
Solution Approach 2:
The patent changes control parameters (duty cycle, frequency) through software to adjust output current. The microcontroller modifies the duty cycle parameter of the pulse width modulation signal to vary the average output current. This parameter-based control approach allows flexible current adjustment without hardware modification, resolving the technical contradiction.
2Adaptability or versatility
If hardware modification is performed to change output current, then output current adaptability is improved, but ease of manufacture and device complexity worsen
Solution Approach 1:
The patent implements a universal control system where a single hardware platform can provide multiple output current levels through software configuration. The microcontroller-based control unit can be programmed to deliver different current profiles for various LED applications. This multi-functionality achieves high adaptability without requiring multiple specialized hardware designs, thus improving ease of manufacture.
Solution Approach 2:
The patent introduces dynamic current control capability through software, allowing the output current to be adjusted in real-time based on different operating conditions. The system can dynamically change current levels, dimming ratios, and switching frequencies without hardware reconfiguration. This dynamic adaptability is achieved through a single flexible hardware design, maintaining ease of manufacture while enhancing versatility.
Data Source
AI summary
A pulse width modulation control unit multiplies a value of a user side setting signal by a value of a dimming signal to obtain a pulse width modulation output current control signal. The pulse width modulation control unit sends the pulse width modulation output current control signal to a light emitting diode driving unit. The light emitting diode driving unit multiplies a value of the pulse width modulation output current control signal by a value of a maximum output current of the light emitting diode driving unit to obtain a light emitting diode pulse width modulation driving current. The light emitting diode driving unit drives a light emitting diode by the light emitting diode pulse width modulation driving current.