Analog LED Driver Circuit for Spectral Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing horticultural lighting systems, such as incandescent, high-intensity discharge, and fluorescent lights, are inefficient, generate excessive heat, and lack control over spectral emission, particularly in the blue region crucial for plant growth, while LED-based systems with microcontroller-driven drivers are costly due to the need for balanced LED string voltages.
Innovation Solution
A LED lamp with driver electronics that includes an AC-DC power supply and a linear topology LED string current control circuit, using potentiometers to adjust total current and percentage of current to each string of LEDs, allowing for independent control of photosynthetic photon flux and spectral power distribution without a microcontroller, enabling flexible spectrum adjustment from blue to red based on plant growth stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If microcontroller-driven LED drivers are used to control spectral emission, then spectral control precision is improved, but device cost increases
Solution Approach 1:
The patent removes the microcontroller from the LED driver circuitry, extracting the complex control element while maintaining spectral control capability through simpler analog circuitry. This reduces device cost while preserving the ability to independently control current to multiple LED strings for spectral adjustment.
Solution Approach 2:
The patent employs inexpensive analog components (potentiometers, operational amplifiers, transistors) instead of expensive microcontrollers. These simple components achieve the spectral control function at a fraction of the cost, making the system economically viable for commercial horticultural applications.
2Illumination intensity
If traditional artificial lighting (incandescent, high-intensity discharge, fluorescent) is used, then illumination intensity is improved, but energy efficiency deteriorates and heat generation increases
Solution Approach 1:
The patent changes the fundamental operating parameters by using LED technology instead of traditional lighting. LEDs convert electrical energy directly to light with minimal heat generation, achieving high illumination intensity while dramatically improving energy efficiency compared to incandescent, high-intensity discharge, or fluorescent alternatives.
3Adaptability or versatility
If LED strings with different voltages are used to achieve flexible spectrum adjustment, then spectral adaptability is improved, but device complexity increases due to voltage balancing requirements
Solution Approach 1:
The patent segments the LED lighting system into multiple independent strings, each with its own current control circuit. This segmentation allows different voltage and wavelength LED strings to be connected in parallel without requiring voltage balancing, as each string operates independently under its own controlled current, simplifying the overall device architecture.
Solution Approach 2:
The patent implements dynamic spectral control through independent potentiometer adjustment for each LED string. Users can dynamically adjust the current distribution among different wavelength strings in real-time, enabling flexible adaptation to various plant growth stages without complex predetermined programming or switching mechanisms.
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 energy-efficient, cost-effective horticultural lighting with precise control over light spectrum and intensity, optimizing plant growth by adjusting light emission to match different growth stages without the heat and cost issues of traditional systems.
Implementation Method 1
LED light sources can be used as artificial lighting inside greenhouses so as to enhance growth and quality of plants
Implementation Method 2
high electro-optic conversion efficiency
Implementation Method 3
a linear topology LED string current control portion including an operational amplifier and a second potentiometer
Implementation Method 4
operate a field effect transistor (FET) in the linear portion of the FETs operation range
Data Source
AI summary
A lamp including a body for containing a light engine that includes at least a first and second string of said light emitters. The lamp includes driver electronics including an AC-DC switching power supply section of a circuit including a first potentiometer for adjusting total current to the light engine; and a linear topology LED string current control section of the circuit including an operational amplifier controlled by a second potentiometer to operate a field effect transistor (FET) in the linear portion of the FETs operation range to adjust a percentage of the total current to the first and second string of the light emitters. Adjusting the total current adjusts the photosynthetic photon flux (PPF) of light emitted by the lamp. Adjusting the percentage of the total current to the first and second string of the light emitters adjusts the spectral power distribution of light being emitted by the lamp.