Dynamic Impedance Control for Solid State Lighting Dimming Stability
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Solution Overview
Problem
Conventional AC dimming circuits face challenges when used with solid state lighting apparatuses, as they may cause erratic operation or commutation due to insufficient AC line current, leading to issues with dimming LEDs effectively.
Innovation Solution
A circuit is introduced that includes an energy dissipating circuit, a detection circuit, and an activation circuit to dynamically alter impedance presented to the power supply, generating a control signal based on power consumption levels and dimming signals, ensuring proper operation of dimming controllers by maintaining adequate AC line current during low power consumption periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional AC dimming circuits are used with solid state lighting apparatuses, then the lighting can be dimmed, but erratic operation or commutation occurs due to insufficient AC line current
Solution Approach 1:
The patent introduces an intermediary load circuit that acts as a mediator between the dimming circuit and the power supply. This load circuit consumes excess power and maintains adequate AC line current during dimmed states, preventing commutation issues while allowing the solid state lighting to operate at reduced illumination levels without erratic behavior
Solution Approach 2:
The patent dynamically changes the load parameter by controlling the switching element to adjust the amount of power consumed by the load circuit. During dimmed states, the load circuit increases power consumption to maintain minimum AC line current requirements, thereby resolving the contradiction between reduced illumination and operational reliability
2Use of energy by moving object
If solid state lighting apparatus consumes less power, then energy efficiency is improved, but AC line current becomes insufficient for proper dimmer operation
Solution Approach 1:
The patent segments the power consumption function into two independent parts: the solid state lighting apparatus that consumes minimal power for efficiency, and the load circuit that consumes additional power to maintain dimmer operation. This segmentation allows each component to fulfill its specific function without compromising the other
Solution Approach 2:
The load circuit serves multiple functions: it maintains adequate AC line current for dimmer operation, provides a stable operating point for the switching regulator, and enables proper dimming control. This multi-functionality resolves the contradiction by making the power system capable of supporting both energy-efficient operation and reliable dimmer control
3Power
If an energy dissipating circuit is dynamically coupled to the power supply, then AC line current is maintained during low power consumption, but device complexity increases
Solution Approach 1:
The patent merges the load circuit with the existing switching regulator and power supply components. The load circuit shares common elements such as the switching element, control circuitry, and power pathways with the main power conversion system, thereby reducing overall device complexity while still achieving the goal of maintaining adequate AC line current during low power consumption periods
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
The solution ensures stable operation of dimming controllers by dynamically adjusting the power supply's impedance, preventing commutation and ensuring consistent dimming performance even at low power consumption levels, thereby maintaining proper functionality of solid state lighting apparatuses.
Implementation Method 1
a detection circuit configured to generate a control signal indicative of a power consumption level in a load circuit coupled to the power supply line
Implementation Method 2
an energy dissipating circuit... configured to alter a level of impedance presented to the power supply
Data Source
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AI summary
A circuit for altering a level of impedance presented to a power supply including a power supply line includes an energy dissipating circuit, a detection circuit configured to generate a control signal indicative of a power consumption level in a load circuit coupled to the power supply line, and an activation circuit configured to controllably couple the energy dissipating circuit to the power supply line in response to the control signal. Methods of operating a solid state lighting apparatus including a power supply and a solid state lighting device coupled to the power supply include detecting a level of power consumption by the solid state lighting device, and coupling an energy dissipating circuit to the power supply in response to the level of power consumption by the solid state lighting device falling below a threshold level.