LED Driver Current Error Reduction via Feedback Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED driver circuits experience significant setting current errors due to the imprecision of discrete components, leading to inconsistent and unpredictable light output, especially at lower current levels, which exceeds acceptable limits and affects reliability and compliance with industry standards.
Innovation Solution
A light fixture system that includes a controller and sensors to measure and correct the setting current, using a setting current correction curve based on actual discrete component values, ensuring the delivered current is calibrated and consistent across a range of settings, thereby minimizing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discrete components (resistors, capacitors, inductors) are used in LED driver circuits to keep costs low, then manufacturing cost is reduced, but setting current precision deteriorates due to component tolerances
Solution Approach 1:
The patent implements a feedback mechanism where a sensor measures the actual setting current delivered to the LED, and a controller compares this measured value with the target current. Based on this comparison, the controller generates a correction signal that adjusts the power supply output to compensate for discrete component tolerances, thereby maintaining current precision without requiring expensive precision components.
Solution Approach 2:
The system dynamically changes the operating parameters of the power supply by applying correction signals that adjust the setting current in real-time. This allows the system to adapt to variations in discrete component values and maintain accurate current delivery across different operating conditions without changing the physical components themselves.
2Device complexity
If standard discrete components with tolerance ranges are used, then device complexity is reduced, but light output consistency deteriorates especially at lower current levels
Solution Approach 1:
The feedback loop continuously monitors the actual current delivered to the LED and adjusts the power supply output accordingly. This ensures consistent light output across the entire current range, particularly at lower current levels where component tolerances have the greatest impact, without adding significant complexity to the device architecture.
Solution Approach 2:
The system performs preliminary calibration by measuring the actual setting current during manufacturing or initial operation and storing correction data. This preliminary action allows the system to pre-compensate for component variations, ensuring consistent light output from the first use without requiring complex real-time adjustments.
3Device complexity
If no current correction is applied, then device complexity remains low, but setting current error exceeds acceptable limits affecting reliability and compliance
Solution Approach 1:
The feedback-based correction system enables the device to meet industry standards for current precision and light output consistency while maintaining relatively simple architecture. The sensor and controller work together to automatically compensate for component tolerances, providing compliance without requiring complex precision component networks or multiple correction circuits.
Data Source
AI summary
A light fixture can include a lighting circuit comprising at least one light source and at least one discrete component. The light fixture can also include a power supply coupled to the lighting circuit, where the power supply provides a setting current to the at least one light source. The light fixture can further include a sensor that measures the setting current flowing to the at least one light source. The light fixture can also include a controller coupled to the power supply and the sensor, where the controller provides, in real time, a setting current correction signal to the power supply to adjust the setting current delivered to the at least one light source. The setting current correction signal can be calibrated to an actual value of the at least one discrete component of the lighting circuit.