LED Driver Phase Shift for Ripple Reduction
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Solution Overview
Problem
Existing systems for driving LED arrays face challenges in efficiently managing supply energy and reducing current ripples, leading to inefficiencies and electromagnetic interference due to simultaneous switching of LEDs, which complicates the management of heat sources and temperature gradients in compact arrangements.
Innovation Solution
A device and method that sense supply signals and apply phase shifts to switching signals of LEDs, allowing for adaptive control of current sources to reduce current ripples and improve energy management by ensuring LEDs are not switched on simultaneously, using a combination of sensing units, control logic, and phase shift algorithms to optimize the load condition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LEDs are switched on simultaneously, then the lighting device can provide maximum illumination, but current ripples increase and electromagnetic interference occurs
Solution Approach 1:
The patent applies periodic action by implementing phased switching of LED rows. Instead of switching all LEDs simultaneously, the control circuit divides the LED array into multiple rows and switches each row at different time intervals within a periodic cycle. This distributes the current draw over time, reducing peak current ripples while maintaining overall illumination levels.
2Illumination intensity
If LEDs are switched on simultaneously, then maximum light output is achieved, but electromagnetic interference increases
Solution Approach 1:
The control circuit implements periodic phased switching where different rows of LEDs are activated in sequence rather than simultaneously. This periodic distribution of switching events reduces electromagnetic interference by avoiding synchronized current transitions across all LEDs, while still achieving the desired total light output through cumulative illumination.
3Area of stationary object
If LEDs are arranged in compact configuration, then space efficiency is improved, but heat management becomes more difficult
Solution Approach 1:
The patent addresses heat management in compact configurations by implementing periodic phased switching of LED rows. This reduces instantaneous thermal load on the compact structure by distributing heat generation over time, preventing excessive temperature gradients while maintaining the space-efficient compact arrangement.
4Object-generated harmful factors
If phase shift is applied to switching signals, then current ripples are reduced, but device complexity increases
Solution Approach 1:
The patent reduces device complexity by segmenting the LED array into multiple rows, each controlled by separate switching signals. This segmentation allows independent phase control of each row without requiring complex individual control circuitry for every LED, simplifying the overall control architecture while still achieving current ripple reduction through phased switching.
Data Source
AI summary
According to an example, a device is provided for driving several light sources, wherein the device is arranged to sense a supply signal and apply a phase shift to a switching signal of at least one of the several light sources based on the sensed supply signal. Also, accordingly a method, a lighting device, a computer program product and a computer-readable medium are suggested.