Multi-Channel LED Protection Circuit with Total Current Regulation
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Solution Overview
Problem
There is a need for a multi-channel LED luminaire that uses a single power supply circuit to maintain a constant total current across all LED channels while ensuring compliance with desired lighting outputs and safety standards, including monitoring individual channel currents for faults like short circuits.
Innovation Solution
The protection circuit includes a total error circuit that compares the total current flowing through the LED channels to a total current limit and adjusts the power supply signal accordingly to maintain constant current. Additionally, a comparator circuit monitors the total current against the summation of individual channel currents to detect faults, triggering the power supply to disable the supply signal and prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single power supply circuit is used to power all LED channels, then circuit layout efficiency is improved, but current monitoring and control complexity increases
Solution Approach 1:
The patent divides the current monitoring function into separate modules: individual channel current sensing circuits for each LED channel, and a total current sensing circuit for the aggregate current. This segmentation allows the single power supply to be efficiently used while maintaining manageable monitoring complexity through modular design.
Solution Approach 2:
The protection circuit is designed to perform multiple functions: monitoring individual channel currents, monitoring total current, detecting faults, and controlling the power supply. This multi-functionality consolidates what could be multiple separate systems into one integrated circuit, improving layout efficiency while keeping complexity manageable.
2Reliability
If total current is regulated to be constant, then safety standard compliance is improved, but lighting output flexibility decreases
Solution Approach 1:
The protection circuit dynamically adjusts the supply signal based on real-time current measurements. The error circuit continuously compares actual total current against the desired current limit and modifies the power supply output accordingly. This dynamic control ensures safety compliance while allowing flexible lighting output through programmable current limits.
Solution Approach 2:
The system implements feedback control where the error circuit receives information about actual current consumption and uses this feedback to adjust the power supply signal. This closed-loop feedback mechanism maintains safety compliance by preventing overcurrent while allowing flexible lighting output through adjustable setpoints.
3Reliability
If individual channel currents are monitored for fault detection, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent implements separate current sensing circuits for each LED channel, with each circuit independently monitoring its channel's current. This segmentation enables reliable fault detection for individual channels while maintaining modular complexity that is easier to manage and diagnose than a monolithic monitoring system.
Solution Approach 2:
The protection circuit acts as an intermediary between the power supply and LED channels, using current sensing circuits as mediators to detect faults. These intermediary sensing circuits provide fault information to the control logic without requiring direct complex interaction between all system components, thereby managing complexity.
Data Source
AI summary
A protection circuit for a multi-channel LED luminaire is provided. Each LED channel is powered by a single power supply circuit via a supply signal. In one aspect, a total error circuit compares the total current flowing through each LED channel to a total current limit, and triggers the power supply circuit to adjust the supply signal based on the comparison. This adjustment results in total current flowing through the LED channels to remain constant, while also conforming to the desired lighting output. In another aspect, the comparator circuit compares the total current to the summation of the individual currents flowing through each LED channel to determine if a fault, such as a short circuit, has occurred. Detection of the fault is triggers the power supply to limit or disable the supply signal, limiting damage to the luminaire, and protecting the safety of users.