Parallel LED Array Current Control Using Induced Fault Detection
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Solution Overview
Problem
In electronic apparatuses with LED arrays connected in parallel, a broken LED can cause overcurrent to flow to remaining LEDs, leading to increased probability of error and heat generation, and existing methods to prevent this result in power loss and heat due to resistance.
Innovation Solution
The electronic apparatus includes sensing and auxiliary inductors connected in series with LED arrays, a variable resistance to adjust current, and an LED driver that identifies errors based on induced voltages to adjust resistance values and power supply modes, preventing overcurrent without power loss or heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a variable resistance is connected to the LED element in series to adjust current, then overcurrent to remaining LED elements is prevented, but power loss and heat generation occur
Solution Approach 1:
The patent introduces a sensing inductor and auxiliary inductor as intermediary components between the power supply and LED arrays. These inductors detect current abnormalities and enable protective action without requiring continuous resistance adjustment, thereby preventing overcurrent while minimizing energy loss compared to continuous variable resistance adjustment.
Solution Approach 2:
The patent implements a feedback mechanism where the sensing inductor continuously monitors current through the auxiliary inductor, and the LED driver adjusts the resistance value of the variable resistance based on the detected induced voltage. This closed-loop feedback system prevents overcurrent by dynamically responding to actual operating conditions rather than using fixed resistance values.
2Reliability
If a variable resistance is connected to the LED element in series to adjust current, then overcurrent to remaining LED elements is prevented, but heat generation occurs
Solution Approach 1:
The sensing inductor and auxiliary inductor serve as intermediary detection components that enable protective action without continuous resistance adjustment. By detecting current abnormalities through electromagnetic induction, the system can trigger protective measures with minimal resistance engagement, thereby preventing overcurrent while significantly reducing heat generation compared to continuous resistance-based current limiting.
Solution Approach 2:
The feedback mechanism allows the system to maintain low resistance values during normal operation (minimizing heat generation) and only increase resistance when overcurrent is detected. The LED driver continuously monitors the induced voltage from the auxiliary inductor and dynamically adjusts the variable resistance, ensuring heat is generated only when necessary for protection.
3Illumination intensity
If LED arrays are connected in parallel to increase luminance, then high-luminance content is provided, but overcurrent flows to remaining LED elements when one breaks
Solution Approach 1:
The patent segments the monitoring function by providing separate sensing inductors and auxiliary inductors for each LED array. This segmentation allows independent detection of current abnormalities in each parallel-connected array, enabling targeted protective action for the specific array with the broken LED while maintaining normal operation of other arrays, thus preserving overall luminance while preventing overcurrent propagation.
Solution Approach 2:
The feedback mechanism monitors each parallel-connected LED array independently through its dedicated sensing and auxiliary inductors. When a break is detected in one array, the system increases resistance specifically for that array through the variable resistance control, preventing overcurrent from affecting other parallel arrays while maintaining their normal luminance output.
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 solution effectively identifies and mitigates overcurrent issues in LED arrays, reducing the probability of additional errors and minimizing power loss and heat, while maintaining light emission luminance and image quality.
Implementation Method 1
based on at least one of a first induced voltage generated on the first auxiliary inductor or a second induced voltage generated on the second auxiliary inductor being a threshold voltage or more, identify that an error occurs in at least one of the first LED array or the second LED array
Data Source
AI summary
An electronic apparatus is provided. The electronic apparatus includes: a plurality of LED arrays disposed in parallel, a first sensing inductor connected to a first LED array of the plurality of LED arrays in series, a first auxiliary inductor disposed adjacent to the first sensing inductor, a second sensing inductor connected to a second LED array of the plurality of LED arrays in series, a second auxiliary inductor disposed adjacent to the second sensing inductor, a variable resistance connected to the plurality of LED arrays and configured to adjust an amount of a current flowing to the plurality of LED arrays according to a resistance value, and an LED driver configured to, based on at least one of a first induced voltage generated on the first auxiliary inductor or a second induced voltage generated in the second auxiliary inductor being a threshold voltage or more, identify that an error occurs in at least one of the first LED array or the second LED array, and adjust the resistance value of the variable resistance based on the identified result.