SSL Circuit Voltage Control for Dimming and Color

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Solution Overview

Problem

High power solid-state lighting (SSL) systems face challenges in efficiently controlling light output and color, particularly with high non-linearity in LED response to voltage, leading to energy wastage, complexity, and compatibility issues with existing AC dimming controls, while also requiring reliable and cost-effective solutions for long-term use.

Innovation Solution

The implementation of a novel circuit design that uses MOSFET switches and voltage dividers to selectively turn on or dim SSL emitters in sequence with voltage changes, allowing for precise control of light output and color, compatibility with both DC and AC power sources, and integration with conventional AC dimming controls, thereby optimizing energy use and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If complex control circuits are used to dim and control light output of SSL fixtures, then light output control capability is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvelight output control capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by utilizing the natural voltage-dependent characteristics of SSL emitters. Instead of complex control circuits, the system varies the operating voltage parameter to achieve dimming and color control. The circuit uses simple voltage division and selection mechanisms that exploit how emitter voltage determines both brightness and color output, transforming a complex control problem into a simple voltage parameter adjustment.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements self-service by designing circuits that automatically adapt to emitter characteristics without external control signals. The voltage divider networks and selector switches are configured to automatically select appropriate emitters based on the applied voltage level. The system serves itself by using the voltage parameter to simultaneously control both the selection and dimming of emitters, eliminating the need for separate control circuits.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If externally controlled dimming power supplies are used, then light output control is improved, but device complexity and installation complexity increase

Engineering Contradiction:
Improvelight output controlVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the power supply and control functions into a single integrated circuit. The dimming control is not a separate external device but is built into the power circuit itself through voltage divider networks and selector switches. This consolidation eliminates the need for separate control wiring and external dimming devices, reducing both device complexity and installation complexity while maintaining full light output control capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal power circuit that performs multiple functions: power conversion, emitter selection, dimming control, and color temperature adjustment. The same voltage control mechanism that powers the emitters also controls their selection and brightness levels. This multi-functional design eliminates the need for specialized dimming power supplies and reduces system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Use of energy by moving object

If SSL systems are designed to optimize light output efficiency, then energy efficiency is improved, but system cost increases

Engineering Contradiction:
Improvelight output efficiencyVSAvoidsystem cost
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent segments the SSL emitter array into multiple groups with different voltage requirements and color characteristics. By dividing the emitters into segments that can be independently selected through voltage control, the system achieves efficient light output by activating only the appropriate segments for given conditions. This segmentation allows cost-effective implementation using simple voltage division rather than requiring expensive individual control circuits for each emitter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses parameter changes in voltage to simultaneously achieve efficient light output and cost reduction. By varying the operating voltage, the system optimizes which emitters are active and at what brightness levels, maximizing light output efficiency. The same voltage parameter changes that improve efficiency also simplify the control circuitry, reducing system cost compared to approaches requiring separate control electronics for each emitter.

Inventive Principle:
Principle #35Parameter changes

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 enables energy-efficient, reliable, and cost-effective control of SSL systems, minimizing energy wastage, reducing thermal issues, and maintaining consistent light output and color, while being compatible with existing infrastructure, thus enhancing the adoption of SSL technology in various applications.

Implementation Method 1

solid state lighting (SSL) refers to a type of lighting utilizing light-emitting diodes (LEDs)

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

the string of SSL emitters is divided into a first group of SSL emitters and a second group of SSL emitters

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 3

After attaining the necessary onset (turn on) voltage, SSL emitter light output (and sometimes color) is highly sensitive to voltage (Vf) applied across the emitter

Methodology Applied
Scientific EffectRectification:

Data Source

PatentUS8710764B2Solid state lighting circuit and controls
Publication Date: 2014.04.29 METROSPEC TECHNOLOGY LLC
  • US8710764B2 patent drawing
  • US8710764B2 patent drawing
  • US8710764B2 patent drawing

AI summary

In some embodiments, a solid state lighting circuit may include one or more of the following features: (a) a plurality of emitters operably connected to a power supply (b) the power supply operably coupled in series with a current limiting device, where one or more of the emitters is bypassed with a switched circuit, and (c) at least one MOSFET switch operably coupled to the voltage divider circuit.