LED Driving Circuit with Linear Current Regulators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED driving circuits face challenges in minimizing power consumption due to variations in load resistance among multiple LEDs, leading to increased power consumption as a result of uneven voltage distribution across different current paths.
Innovation Solution
The implementation of a feed-forward control LED driving circuit with multiple linear current regulators and a control circuit that dynamically adjusts currents to maintain equal current flow through each set of LEDs, using a power supply circuit, comparators, power switches, and resistors to minimize power consumption while ensuring uniform brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the input voltage is increased to ensure the largest load resistance LED set can be driven sufficiently, then all LEDs can be driven, but power consumption increases due to remaining cross-voltages in other current paths
Solution Approach 1:
The patent divides the LED driving system into multiple independent current paths, each with its own linear current regulator. This segmentation allows each LED set to be driven independently at its optimal current level, eliminating the need to increase input voltage for the entire array to accommodate the highest resistance path.
Solution Approach 2:
Each current path is equipped with its own linear current regulator that provides localized voltage regulation. This allows each LED set to receive the precise voltage needed for its specific load resistance, rather than all LEDs sharing a common voltage that must be high enough for the maximum resistance path.
2Manufacturing precision
If linear current regulators are added to each current path to control current equality, then LED brightness uniformity improves, but device complexity increases
Solution Approach 1:
The patent uses linear current regulators that adjust voltage parameters dynamically based on the specific load resistance of each LED set. By changing the voltage parameter in response to load variations, the system maintains constant current flow through each path without requiring complex feedback control circuits.
3Productivity
If the number of LEDs in each set increases, then total light output improves, but additional power consumption increases proportionally
Solution Approach 1:
The patent implements dynamic voltage regulation for each current path through linear current regulators. As the number of LEDs in a path increases and load resistance changes, the regulator dynamically adjusts the voltage to maintain optimal current flow, preventing excessive power consumption that would occur with fixed voltage driving.
Data Source
AI summary
A light-emitting diode (LED) driving circuit may include: a power supply circuit, arranged to provide power to a first set of LEDs and a second set of LEDs; a first linear current regulator and a second linear current regulator, where any linear current regulator of the linear current regulators and a corresponding set of LEDs within the sets of LEDs are coupled to each other in series and coupled between a power terminal and a ground terminal of the power supply circuit; and a control circuit, coupled to the linear current regulators, arranged to control the linear current regulators to drive the sets of LEDs, respectively, to make currents respectively passing through the sets of LEDs be substantially equal to each other. Aforementioned any linear current regulator may include a comparator, a power switch, and a resistor, and the control circuit may include a detection circuit and parameter control circuits.