SSL Assembly Capacitor Sizing via Directional Conduction
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Solution Overview
Problem
Solid state lighting (SSL) assemblies face challenges with large electrolytic capacitors, which increase dimensions and decrease lifetime due to high failure rates, necessitating the use of smaller capacitors like ceramic or film capacitors to stabilize energy supply and prevent flickering.
Innovation Solution
The proposed SSL assembly incorporates a capacitor coupled in parallel with the SSL device, a directional conducting device between the capacitor's output terminal and supply terminal, and a supply switch between the output terminal and ground, allowing for efficient charging and power management using diodes or transistors to control current flow and reduce capacitor size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If large electrolytic capacitors are used to stabilize energy supply and prevent flickering, then light quality is improved, but the overall dimensions of the SSL assembly increase and lifetime decreases
Solution Approach 1:
The patent extracts the harmful electrolytic capacitor from the circuit and replaces it with a combination of smaller ceramic/film capacitors and a directional conducting device. The directional conducting device isolates the capacitor during reverse voltage conditions, eliminating the need for large electrolytic capacitors while maintaining energy supply stability and preventing flickering.
Solution Approach 2:
The directional conducting device acts as an intermediary between the capacitor and the SSL device. It allows the capacitor to stabilize energy supply during normal operation while blocking reverse voltage that would otherwise damage the capacitor and limit assembly lifetime. This mediator enables the use of smaller, more reliable capacitors.
2Stability of the object's composition
If large electrolytic capacitors are used to stabilize energy supply, then flickering is prevented, but the overall dimensions of the SSL assembly increase
Solution Approach 1:
The patent removes the large electrolytic capacitor from the design and replaces it with smaller ceramic or film capacitors combined with a directional conducting device. This extraction eliminates the volume penalty while maintaining the energy supply stabilization function needed to prevent flickering.
Solution Approach 2:
The patent changes the capacitor type parameter from electrolytic to ceramic or film, and introduces a directional conducting device to modify the operating conditions. This parameter change allows smaller capacitance values to achieve the same energy supply stability, thereby reducing assembly dimensions.
3Duration of action of stationary object
If small capacitors are used instead of large electrolytic capacitors, then assembly dimensions are reduced and lifetime is improved, but energy supply stability may be compromised
Solution Approach 1:
The directional conducting device serves as an intermediary that protects small capacitors from reverse voltage damage while allowing them to perform energy supply stabilization. This enables the use of small, long-lived ceramic or film capacitors without compromising energy supply stability, as the directional conducting device ensures they operate only within their voltage ratings.
Solution Approach 2:
The directional conducting device provides beforehand protection by blocking reverse voltage before it can damage the small capacitors. This prior cushioning against voltage stress allows the use of smaller, more reliable capacitors with confidence that their lifetime will not be compromised by voltage excursions.
4Duration of action of stationary object
If a directional conducting device is added to enable small capacitor usage, then capacitor size is reduced and lifetime is improved, but device complexity increases
Solution Approach 1:
The patent extracts the reverse voltage protection function from the capacitor selection decision and implements it separately through a directional conducting device. This allows the use of small, long-lived capacitors while isolating the complexity of voltage management in a dedicated component with simple on/off characteristics.
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 configuration enables stable start-up behavior, reduces capacitor size, and enhances the overall efficiency and reliability of SSL assemblies by redirecting current flow and stabilizing voltage, while minimizing the risk of overvoltage and extending the assembly's lifespan.
Implementation Method 1
A capacitor is coupled in parallel with the SSL device
Implementation Method 2
The directional conducting device is configured to conduct in a direction from the output terminal to the supply terminal and to isolate in the opposite direction
Implementation Method 3
The directional conducting device may be e.g. a diode
Data Source
AI summary
A solid state lighting SSL assembly comprises an SSL device, a capacitor, a directional conducting device and a supply switch. The capacitor is coupled in parallel with the SSL device. The directional conducting device is coupled between an output terminal of the capacitor and a supply terminal which provides a supply voltage for the SSL assembly. The directional conducting device is configured to conduct in a direction from the output terminal to the supply terminal and to isolate in the opposite direction. The supply switch is coupled between the output terminal and ground. In addition, a method for operating a solid state lighting SSL assembly is proposed.