LED Lamp Power Control via High-Frequency Switching
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Solution Overview
Problem
Existing LED lamps experience unstable power consumption and varying light output due to differences in ballast types, leading to inconsistent performance across different luminaire designs.
Innovation Solution
An LED lamp with a plurality of LEDs connected in groups, rectifier circuits, a control circuit to estimate power, and a switching circuit that adjusts the duty cycle at a frequency of at least 300 kHz to maintain stable power consumption, comprising a first switch for switching between circuit configurations and an inductive element with a second switch to bypass when current thresholds are met, enabling adaptation to various ballast types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an LED lamp is used with different types of ballasts (magnetic, constant current, constant power), then the lamp can be compatible with various luminaire designs, but the power consumption and light output become unstable and vary significantly
Solution Approach 1:
The LED lamp employs a dynamic control circuit that continuously monitors the ballast type and adjusts the driving parameters in real-time. The control circuit detects whether the connected ballast is magnetic, constant current, or constant power type, and dynamically modifies the LED forward current and switching frequency accordingly, transforming a static LED design into an adaptive system that maintains stable operation across different ballast types
Solution Approach 2:
The invention changes multiple electrical parameters including forward voltage, forward current, and switching frequency based on the detected ballast type. For magnetic ballasts, the control circuit adjusts parameters to compensate for their inductive characteristics, while for electronic ballasts it modifies parameters to match their constant current or constant power behavior, thereby maintaining consistent power consumption and light output across all ballast types
2Ease of manufacture
If a straightforward replacement of fluorescent lamp with LED lamp is performed, then installation is simple, but the entire luminaire may fail due to incompatibility with the ballast
Solution Approach 1:
The LED lamp is designed with multi-functional capability to operate with magnetic ballasts, constant current electronic ballasts, and constant power electronic ballasts, as well as ballast-less luminaires. The integrated control circuit automatically detects the ballast type and adjusts operating parameters accordingly, making the LED lamp a universal replacement solution that maintains high reliability across different luminaire configurations without requiring complex installation procedures
3Power
If constant power ballasts are used to drive LED lamps, then the ballast attempts to maintain design power output, but the power consumption becomes unpredictable and varies across different ballast models
Solution Approach 1:
The LED lamp incorporates a feedback control mechanism where the control circuit continuously monitors the actual power consumption and light output, compares it with the target values, and adjusts the driving current and switching parameters in real-time. This closed-loop feedback system compensates for variations between different constant power ballast models, ensuring consistent and predictable power consumption and light output across all ballast types
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 achieves stable and predictable lamp power consumption and light output, independent of the make or model of the ballast, ensuring consistent performance across different luminaire configurations.
Implementation Method 1
one or more rectifier circuits adapted for rectifying an electrical current received from the luminaire for supply to the LEDs
Implementation Method 2
a switching circuit comprising a first switch for switching the plurality of groups of LEDs between a plurality of different circuit configurations at a switching frequency of at least 300 kHz
Implementation Method 3
an inductive element with a second switch to bypass when current thresholds are met
Data Source
AI summary
An LED lamp (1) for use in a luminaire (2), the LED lamp (1) comprising a plurality of LEDs (14) connected in a plurality of groups (15, 16); one or more rectifier circuits (10, 10a, 10b) adapted for rectifying an electrical current received from the luminaire (2) for supply to the LEDs (14); a first control circuit (24) adapted to estimate electrical current or electrical power received by or used by the LED lamp (1), and adapted to generate an output on the basis of the estimate; and a switching circuit (20) comprising a first switch (21) for switching the plurality of groups of LEDs (15, 16) between a plurality of different circuit configurations at a switching frequency of at least 300 kHz and according to a duty cycle; wherein the switching circuit (20) is configured to adjust the duty cycle in dependence on the output of the first control circuit (24) to adjust the electrical power used by the LED lamp (1).