Filament Emulation Circuit for LED Tube Lamp Retrofit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Retrofitting LED tube lamps to fluorescent electronic ballasts results in inefficiencies due to mismatched power ratings, leading to power loss and reduced efficiency, as the ballast is not optimized for low-power LED loads, and existing filament emulation circuits require significant space and power for switches and energy storage.
Innovation Solution
A filament emulation circuit with a Bi-Pin connector, a switching element, and an energy storage device, powered by a conversion circuit, which provides a controllable voltage and reduces power consumption by using a low-voltage connection, allowing the ballast to recognize a fluorescent tube and adjust power output, and includes a relay for pin safety and minimal power usage in standby mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a filament emulation circuit with switches is used to improve compatibility with the electronic ballast, then the compatibility and pin safety are improved, but the power consumption and space requirements increase
Solution Approach 1:
The energy storage device is powered by the ballast output through the filament emulation circuit, allowing the switching element to be self-powered without requiring separate power supply wiring. The circuit uses the ballast's own output to charge the energy storage device, which then powers the switching element, creating a self-sustaining system that reduces external power requirements
Solution Approach 2:
The filament emulation circuit serves multiple functions: it provides compatibility with the ballast, ensures pin safety through switching, and powers itself using the ballast output. The energy storage device acts as both a power source for the switching element and a component that works with the ballast's output, consolidating multiple functions into a single integrated circuit
2Reliability
If the switching element is powered continuously to maintain pin safety, then the safety function is improved, but the power consumption increases
Solution Approach 1:
The switching element is powered periodically through the charging and discharging cycles of the energy storage device, rather than continuously. The ballast output charges the energy storage device during operation, and the stored energy powers the switching element during standby or when safety intervention is needed, creating a periodic power supply pattern that reduces overall consumption
Solution Approach 2:
The energy storage device is charged in advance during ballast operation, storing energy that can be used later when the lamp is off or in standby mode. This preliminary charging action ensures the switching element can be powered when needed for safety without requiring continuous power supply during operation
3Adaptability or versatility
If the filament emulation circuit is placed at the end caps of the LED tube lamp, then the compatibility with ballast is improved, but the space required in the lamp increases
Solution Approach 1:
The filament emulation circuit combines multiple components (energy storage device, switching element, controller) into a single integrated unit that can be placed in the end cap of the LED tube lamp. This merging of functions into one compact circuit reduces the overall space required compared to having separate components distributed throughout the lamp
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 enhances power efficiency and reduces space requirements by providing a stable power supply to the switching elements, allowing the LED tube lamp to operate effectively with the ballast while minimizing power consumption during standby, and enabling independent control of the lamp for additional features like dimming and color changes.
Implementation Method 1
a first energy storage device coupled between the first power connection and the second power connection, a first controller for controlling the switching element, wherein the first controller is arranged for receiving power from the first energy storage device
Implementation Method 2
a first switching element arranged to prevent a current to flow between the first power connection and the second power connection when the first switching element is set in a non-conductive state
Implementation Method 3
the filament emulation circuit further comprises a first conversion circuit arranged to provide power to the first energy storage device, wherein the first energy storage device is coupled between the first power connection and the second power connection via the first conversion circuit
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a filament emulation circuit (7) located on one end of a retrofittable tubular light emitting diode lamp (2) for operating with a fluorescent ballast (1) comprising a first power connection and a second power connection for receiving an output power of the fluorescent ballast (1), a first switching element (3) arranged to prevent a current to flow between the first power connection and the second power connection when 5 the first switching element (3) is set in a non-conductive state, a first energy storage device (10) coupled between the first power connection and the second power connection, a first controller for controlling the first switching element (3), wherein the first controller is arranged for receiving power from the first energy storage device (10).