LED Lighting System with Parallel Current Control and Shunt
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Solution Overview
Problem
Conventional LED lighting systems face inefficiencies in energy transfer, with significant heat wastage in peripheral components and inability to maintain LEDs within safe operating regions due to variations in ambient temperature, LED forward voltage, and input power sources, leading to under-performance or over-operation.
Innovation Solution
The implementation of secondary circuitry connected in parallel with the LED array to maintain constant current, using current and temperature sensing elements with a control switch to adjust current, and incorporating a shunt load to manage excess current, along with a capacitor for energy storage and smoothing, allowing for efficient energy transfer and wide-angle illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional LED lighting systems are used with simple power sources and peripheral components, then the device complexity is reduced, but energy transfer efficiency deteriorates with significant heat wastage in peripheral components
Solution Approach 1:
The patent implements feedback control by sensing the actual current through the LED array and using this information to adjust the current through secondary circuitry. The control switch modifies the current distribution based on sensed array state, ensuring optimal energy transfer to LEDs while minimizing heat wastage in peripheral components. This closed-loop feedback mechanism resolves the contradiction by intelligently managing power distribution without requiring overly complex circuitry.
Solution Approach 2:
The patent introduces dynamic current adjustment capability through the control switch that can modify current distribution between the LED array and secondary circuitry based on real-time conditions. This dynamic adaptation allows the system to optimize energy transfer efficiency under varying operating conditions, resolving the contradiction between simple circuit design and energy efficiency by making the circuit behavior adaptive rather than static.
2Illumination intensity
If LEDs are operated at higher current to maximize light output, then illumination intensity is improved, but reliability deteriorates as LEDs may operate outside safe operating regions
Solution Approach 1:
The patent uses feedback control to continuously monitor the LED array current and adjust operating conditions to maintain LEDs within safe operating regions. The control switch modifies current distribution based on sensed array state, preventing over-current conditions that would reduce reliability while maximizing light output within safe limits. This resolves the contradiction by dynamically optimizing the operating point.
Solution Approach 2:
The patent incorporates protective circuitry that prevents LEDs from operating outside safe regions by anticipating and preventing harmful current levels before they occur. The control mechanism ensures current remains within manufacturer-specified limits, providing a safety margin that protects against reliability degradation while maintaining maximum safe light output.
3Illumination intensity
If forward voltage varies within LED wafer to maximize individual LED performance, then illumination intensity is improved, but device complexity increases to manage voltage variations across multiple LEDs
Solution Approach 1:
The patent combines multiple LEDs into series and parallel arrangements to create a unified LED array that operates at a common current level. By merging individual LED operations into a collective array driven by unified current control, the system manages forward voltage variations without requiring complex individual LED control circuitry. This resolving the contradiction by achieving coordinated operation through current control rather than voltage control.
Solution Approach 2:
The patent creates a universal current control mechanism that serves all LEDs in the array simultaneously, regardless of individual forward voltage variations. The control switch and sensing circuitry provide a unified control function that adapts to the collective array characteristics rather than requiring separate control for each LED. This multi-functional approach manages voltage variations efficiently without increasing circuit complexity.
4Use of energy by moving object
If ambient temperature increases causing forward voltage to decrease, then energy transfer to LEDs is improved, but reliability deteriorates as current increases exponentially
Solution Approach 1:
The patent implements feedback control that senses the LED array state (including temperature effects) and adjusts current distribution through the control switch. When temperature increases cause forward voltage to decrease and current to rise, the feedback mechanism detects this condition and modifies current flow to maintain safe operating levels. This resolves the contradiction by dynamically compensating for temperature-induced voltage changes while preserving energy transfer efficiency within safe limits.
Solution Approach 2:
The patent incorporates protective measures that counteract the harmful effects of temperature-induced current increase before they can damage the LEDs. The control circuit anticipates the exponential current rise that occurs with temperature increase and takes preliminary action to limit current through the control switch, preventing reliability degradation while maintaining efficient operation within safe boundaries.
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 optimizes energy transfer to LEDs, minimizing heat wastage and maintaining them within safe operating regions, resulting in improved efficiency and extended service life, while enabling wide-angle illumination and convenient mounting for after-market bulb replacements.
Implementation Method 1
a capacitor for energy storage and smoothing
Implementation Method 2
light-emitting, solid-state element such as a light-emitting diode (LED)
Data Source
AI summary
A lighting system has an array (100) of at least one light-emitting solid-state element such as a light-emitting diode (LED) or a laser diode. A voltage source (10), which may supply either alternating or direct current, energizes the array. Array state circuitry (125; Q2, R2), electrically connected in series with the array (100), senses at least one state of the array, such as the amount of current passing through the array, or temperature. Secondary circuitry (127; R1, Q1; 200, 201, 202; 200, R4, Q1; 126, 127) is connected in parallel with the array (100). A switching component (Q1; Q1, Q3; 202) adjusts the current passing through the secondary circuitry in accordance with the sensed state of the array such that current through the array is maintained substantially constant. A third, parallel, excess current shunt path may also be provided, in which case so is excess current shunt circuitry, which senses current flowing in the secondary circuitry and shunts current in the secondary circuitry in excess of an excess current threshold to the excess current shunt path, whereby overflow current above a first threshold for the array (100) is shunted away from the array and excess current above a second threshold is shunted from the secondary circuits to the excess current shunt circuitry. A wide-angle mounting arrangement is also provided for the array.