Surge Protection Circuit for LED Drivers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED panels in lighting solutions experience high failure rates due to common-mode current surges, which are facilitated by Y-capacitors in LED drivers, leading to damage from parasitic capacitances, and existing solutions either compromise EMI performance or require costly custom designs.
Innovation Solution
A surge-protection arrangement that includes high impedance and low impedance components connected in series and parallel with the load, respectively, and a ground connection to redirect surge currents away from the load, maintaining EMI neutrality and avoiding the need for bypass capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a Y-capacitor is used between primary and secondary windings of the driver transformer to reduce EMI, then electromagnetic interference is reduced, but common-mode current surges are facilitated and LED panels are vulnerable to surge damage
Solution Approach 1:
The patent segments the surge protection function by introducing a separate surge protection circuit with high impedance arrangement (inductor) and low impedance arrangement (capacitor) that operates independently from the Y-capacitor EMI damping system. This segmentation allows the Y-capacitor to maintain its EMI reduction function while the surge protection circuit handles surge current diversion, resolving the contradiction between EMI performance and surge protection.
Solution Approach 2:
The patent introduces an intermediary surge protection circuit between the driver transformer and the LED panel. This intermediary circuit includes a high impedance arrangement (inductor) that discourses surge current and a low impedance arrangement (capacitor) that provides a safe path to ground, acting as a mediator that protects the LED panel from surge damage without affecting the Y-capacitor's EMI damping function.
2Object-affected harmful factors
If the Y-capacitor is split or removed to prevent surge current, then LED damage is avoided, but EMI performance deteriorates severely
Solution Approach 1:
The patent segments the protection functions by separating surge protection (high impedance arrangement + low impedance arrangement) from the EMI damping function (Y-capacitor). This allows both functions to operate independently without compromising each other, resolving the contradiction where removing Y-capacitor would protect against surges but severely worsen EMI performance.
Solution Approach 2:
The patent creates a multi-functional system where the Y-capacitor continues to provide EMI damping while the added surge protection circuit (high and low impedance arrangements) provides surge current protection. This universal approach allows the system to simultaneously achieve both EMI reduction and surge protection without sacrificing either function.
3Object-affected harmful factors
If bypass capacitors are added across each individual LED to divert surge current, then LED damage is prevented, but manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent creates a universal surge protection solution that works with standard LED panel designs without requiring custom bypass capacitors across each LED. The high impedance arrangement (inductor) and low impedance arrangement (capacitor) provide a system-level protection mechanism that is compatible with conventional LED panel architectures, significantly reducing manufacturing complexity and cost.
Solution Approach 2:
The patent uses inexpensive, readily available components (inductor and capacitor) in a simple series-parallel arrangement that provides effective surge protection without requiring expensive custom-designed bypass capacitors for each LED. This approach uses cheap, standard components to achieve the same protection effect that would otherwise require costly custom designs.
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 protects LED components from surge damage without compromising EMI performance or requiring custom designs, ensuring reliable operation and high consumer satisfaction by diverting surge currents safely to ground, thus preventing LED panel failures.
Implementation Method 1
the high-impedance arrangement is realized to discourage a common-mode surge current from entering the load
Implementation Method 2
the low-impedance arrangement is realized to encourage a common-mode surge current to bypass the load into the ground connection
Implementation Method 3
a heat-dissipating load thermally connected to a heat sink of the load
Data Source
AI summary
The invention describes a surge-protection arrangement (1) for an electronic device (3) comprising a heat-dissipating load (10) thermally connected to a heat sink (107) of the load (10), which surge protection arrangement (1) comprises at least one high impedance arrangement (ZHI, ZHI_N, ZHI_P) connected in series with the load (10); at least one low impedance arrangement (ZLO, ZLO_N, ZLO_P) connected in parallel with the load (10); and a ground connection (FE) arranged to electrically connect the heat sink (107) and a low impedance arrangement (ZLO, ZLO_N, ZLO_P); wherein the high-impedance arrangement (ZHI, ZHI_N, ZHI_P) is realized to discourage a common-mode surge current (Is) from entering the load (10), and the low- impedance arrangement (ZLO, ZLO_N, ZLO_P) is realized to encourage a common-mode surge current (Is) to bypass the load (10) into a ground connection (FE). The invention further describes an electronic device (3) comprising a load (10) with a number of heat-dissipating components (100) thermally connected to a heat sink (107) of the load (10); a driver (20) realized to drive the load (10); and such a surge protection arrangement (1). The invention also describes a driver (20) realized to drive an LED lighting circuit (10) and comprising such a surge protection arrangement (1); and a method of providing protection against a common-mode surge current (Is) through an electronic device (3) comprising a heat-dissipating load (10) thermally connected to a heat sink (107) of the load (10).