Switching Controller for Phase-Cut Power Supply Waveform Distortion

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Solution Overview

Problem

Phase-cut powering methods disrupt the voltage waveform, causing compatibility issues with non-resistive loads and leading to high conducted emissions, which are problematic for LED lamps and smart devices, and result in inefficient energy delivery and increased heat dissipation.

Innovation Solution

A controller apparatus with a switch that alternates between conductive and linear states to continuously supply power to the load, reducing waveform distortion and electromagnetic interference (EMI) by allowing the power supply circuit to charge and discharge cyclically, using a feedback circuit to regulate the switch's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If phase-cut powering is used to extract energy from the power supply, then the controller circuit can be powered, but the voltage waveform is disrupted causing compatibility issues with non-resistive loads

Engineering Contradiction:
Improvepower extraction for controllerVSAvoidcompatibility with load types
Core Design Contradiction:
Use of energy by stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent segments the power extraction process into distinct phases: a first phase where the switch is non-conductive and allows full power to the load, and a second phase where the switch is conductive to bypass the power supply circuit and extract energy. This segmentation enables selective energy extraction without continuous waveform disruption, resolving the contradiction between powering the controller and maintaining load compatibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic action by cycling the switch between non-conductive and conductive states at specific intervals. During non-conductive periods, full power flows to the load; during conductive periods, energy is extracted to power the controller. This periodic switching enables continuous controller operation while maintaining load compatibility during non-extraction phases.

Inventive Principle:
Principle #19Periodic action

2Use of energy by stationary object

If phase-cut powering is used to power the controller circuit, then energy can be derived from the mains, but high conducted emissions and EMI result

Engineering Contradiction:
Improvemains power extractionVSAvoidconducted emissions and EMI
Core Design Contradiction:
Use of energy by stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the power supply circuit from the main power path by placing it in parallel with the load, connected through a switch. This extraction allows the controller to be powered separately from the load power path, eliminating the EMI and waveform disruption that would otherwise affect the load while still enabling mains power extraction for controller operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The switch acts as an intermediary element that mediates between the mains power supply and the parallel branches (load and power supply circuit). By controlling the switch state, the system can selectively connect or disconnect the power supply circuit from the mains without affecting the load, thereby eliminating EMI while maintaining power extraction capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by stationary object

If the switch operates in phase-cut mode to power the controller, then energy can be harvested, but waveform distortion increases and heat dissipation increases

Engineering Contradiction:
Improveenergy harvesting from mainsVSAvoidheat dissipation
Core Design Contradiction:
Use of energy by stationary objectVSLoss of energy

Solution Approach 1:

The patent inverts the traditional phase-cut approach by placing the power supply circuit in parallel with the load rather than in series. Instead of cutting power to both load and controller simultaneously, the switch selectively connects the power supply circuit to the mains during specific phases while the load receives continuous power. This inversion eliminates waveform distortion and reduces heat dissipation while maintaining energy harvesting capability.

Inventive Principle:
Principle #13The other way round (Inversion)

4Reliability

If standby current is maintained through the lamp to keep controller powered, then the controller remains operational, but unnecessary energy is consumed

Engineering Contradiction:
Improvecontroller standby operationVSAvoidstandby current consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the controller power supply from the load current path by creating a separate parallel branch. The power supply circuit connects directly to the mains through the switch, independent of the load. This extraction eliminates the need to maintain standby current through the lamp, allowing the controller to remain operational during standby while eliminating unnecessary energy consumption through the load.

Inventive Principle:
Principle #2Taking out (Extraction)

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 ensures continuous current flow to the load without waveform disruption, enhancing compatibility with various load types, reducing EMI, and minimizing heat dissipation, while maintaining efficient energy delivery.

Implementation Method 1

the switch is adapted to continue a current of said first type of AC supply by alternately: being fully conductive; and operating in a linear state to allow the power supply circuit to obtain power from the AC input

Methodology Applied
Scientific EffectLinear operation of switch:

Data Source

PatentEP3871470B1Electronic controller apparatus and control method
Publication Date: 2023.01.11 SIGNIFY HOLDING BV
  • EP3871470B1 patent drawingFigure 1~2
  • EP3871470B1 patent drawingFigure 3
  • EP3871470B1 patent drawingFigure 4~5

AI summary

An electronic controller apparatus comprises a controller circuit for controlling an external load and a power supply circuit to power the controller circuit. A switch is adapted to alternately be conductive to bypass the power supply circuit from the input or allow the power supply circuit to obtain power from the input. A linear operation of the switch is used to reduce current and voltage waveform distortion when power is being obtained from the input.