Light Dimming Device Controller Power Stabilization

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Solution Overview

Problem

Existing light-dimming devices face instability in controlling the lighting state of illumination loads due to poor accumulation of control power in electrolytic capacitors, leading to unstable operation of the controller and difficulty in maintaining a consistent lighting state.

Innovation Solution

A light-dimming device configuration that includes a power supply module with a rectifier circuit, a capacitor, and a constant voltage circuit, where the capacitor is charged until it reaches a threshold voltage, allowing the controller to initiate a PWM signal for switching the MOSFETs near zero voltage, ensuring stable operation and consistent lighting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the switch is in OFF state with a certain conduction angle, then the light output is adjusted, but the control power cannot be accumulated properly in the electrolytic capacitor

Engineering Contradiction:
Improvelight outputVSAvoidcontrol operation stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies preliminary action by charging the electrolytic capacitor to a predetermined threshold voltage before the switch turns OFF. This ensures that sufficient control power is accumulated in advance, preventing controller operation instability that would occur if charging relied solely on the limited current during the switch's OFF state. The capacitor is proactively charged during the switch's ON state or before switching, ensuring reliable controller power supply regardless of the subsequent conduction angle.

Inventive Principle:
Principle #10Preliminary action

2Illumination intensity

If the conduction angle of the switch is small, then the light output is reduced, but the current through the illumination load may become insufficient to charge the capacitor

Engineering Contradiction:
Improvelight output levelVSAvoidcontrol power accumulation
Core Design Contradiction:
Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The patent implements preliminary action by accumulating charge in the electrolytic capacitor before the switch transitions to OFF state. This allows the system to prepare sufficient control power in advance, ensuring that even when the subsequent conduction angle is small and current flow is limited, the controller maintains stable operation with adequate power supply from the pre-charged capacitor.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the switch turns OFF from ON state at non-zero AC voltage, then phase control is achieved, but the capacitor charging time is reduced

Engineering Contradiction:
Improvephase controlVSAvoidcapacitor charging period
Core Design Contradiction:
Ease of operationVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by ensuring the electrolytic capacitor is charged to the threshold voltage before the switch turns OFF during phase control operation. This proactive charging approach allows the system to maintain adequate control power reserves even when the switch's ON duration is limited by phase control requirements, ensuring continuous stable controller operation without extending the switch's ON time beyond what phase control demands.

Inventive Principle:
Principle #10Preliminary 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 configuration stabilizes the operation of the controller and maintains a consistent lighting state for the illumination load, reducing noise and enabling stable control of the lighting state, even at low light output levels.

Implementation Method 1

a rectifier circuit configured to convert a voltage V1 between the first terminal (1) and the second terminal (2) into a full-wave rectified voltage

Methodology Applied
Scientific EffectRectification:

Implementation Method 2

a capacitor (14) configured to be charged by the constant voltage circuit (13)

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3128815B1Light-dimming device
Publication Date: 2020.04.29 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3128815B1 patent drawingFigure 1
  • EP3128815B1 patent drawingFigure 2

AI summary

A light-dimming device (10) includes a switch (3) including a switching device (7), a controller (4), and a power supply module (5). The power supply module (5) includes a capacitor (14) to be charged by a constant voltage circuit (13). The controller (4) includes a driver circuit (8), a zero-cross detection circuit (9), a detecting circuit (21), and a control circuit (11), and receive electric power from the capacitor (14). The driver circuit (8) drives the switching device (7) in accordance with a PWM signal (S1). The control circuit (11) starts generation of a pulse, to be contained in the PWM signal (S1), for turning on the switching device (7) after the zero-cross detection circuit (9) detects zero-cross and also a voltage (V2) across the capacitor (14) is threshold or more.