LED Power Supply Timing Offset for Peak Current Reduction

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Solution Overview

Problem

Existing light source systems with multiple LED generators face inefficiencies in power supply due to the need to handle peak power requirements that are only utilized for a fraction of the time, leading to suboptimal efficiency and electromagnetic interference.

Innovation Solution

A method that involves temporally offsetting the activation of LED generators to minimize simultaneous activation, allowing the power supply unit to be dimensioned based on lower peak power, optimizing power usage and reducing electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the power supply unit is dimensioned to handle peak power requirements of all LED generators, then all generators can be activated simultaneously, but the power supply unit operates at low efficiency for most of the time and generates electromagnetic interference

Engineering Contradiction:
Improvecapability to activate all generators simultaneouslyVSAvoidpower supply efficiency
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent applies periodic action by activating LED generators in alternating time periods rather than simultaneously. The control unit divides the activation into phases where different subsets of generators are activated in different periods, allowing the power supply to operate at optimized power levels for each phase while maintaining overall system functionality.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent segments the set of LED generators into multiple subsets that are activated at different times. The control unit manages these segmented groups to ensure that the total power consumption remains within optimized limits while still achieving the desired lighting效果 through coordinated activation of different subsets.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the power supply unit is dimensioned to handle peak power requirements, then simultaneous activation is possible, but the unit size and cost increase

Engineering Contradiction:
Improvesimultaneous activation capabilityVSAvoidpower supply unit size
Core Design Contradiction:
Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

By implementing periodic activation patterns, the power supply unit only needs to be dimensioned for the peak power required during individual activation phases rather than the sum of all generators. This reduces the overall size and cost of the power supply unit while maintaining the capability to activate all generators, just not simultaneously.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system activates only a subset of generators at any given time rather than all generators simultaneously. This partial action approach allows the power supply to be sized for lower peak requirements while still achieving complete lighting coverage through sequential activation of different subsets.

Inventive Principle:
Principle #16Partial or excessive action

3Illumination intensity

If all LED generators are activated simultaneously at peak power, then maximum light output is achieved, but electromagnetic interference increases

Engineering Contradiction:
Improvemaximum light outputVSAvoidelectromagnetic interference
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The control unit implements periodic activation where different subsets of LED generators are activated in alternating time periods. This distributes the electromagnetic interference over time rather than concentrating it, reducing peak EMI levels while maintaining overall maximum light output through coordinated sequencing of different subsets.

Inventive Principle:
Principle #19Periodic action

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

This approach results in a more efficient power supply unit with lower peak power requirements, improved efficiency, and reduced electromagnetic interference, enabling cost-effective and efficient operation.

Implementation Method 1

by varying the duty cycle of the power supply (i.e. the activation interval) of the generator, that is to say by operating in accordance with a pulse width modulation (PWM) diagram

Methodology Applied
Scientific EffectPulse Width Modulation (PWM):

Data Source

PatentEP2502463B1Method for supplying power to light sources, corresponding power supply unit and light source
Publication Date: 2014.07.30 OSRAM GMBH
  • EP2502463B1 patent drawingFigure 1~2
  • EP2502463B1 patent drawingFigure 3~6
  • EP2502463B1 patent drawingFigure 4a~4b

AI summary

A method for supplying power to a plurality of light generators (CH1, CH2, CH3) which emit respective chromatically different light radiations that can be mixed with one another to produce a mixed light radiation by selectively activating said generators with respective supply powers (P1, P2, P3) over respective activation intervals (T1, T2, T3) included in an activation period (T), provides for: - identifying (102) at least one pair of generators (CH1, CH2; CH2, CH3) for which the sum of the respective activation intervals (T1, T2; T2, T3) is less than said activation period (T), and - temporally offsetting the activation (106) of the generators (CH1, CH2; CH2, CH3) in the one pair, avoiding simultaneous activation.