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Will Low-Voltage Light Strips Flicker? In-Depth Analysis of the Causes of Flickering, Detection Methods, and Solutions
1. Definition and Industry Standards of Flicker
Flicker refers to the periodic fluctuation in light brightness caused by variations in electric current. According to the CIE TN 006-2016 standard, flicker is perceptible to the human eye when the light fluctuation frequency is below 80Hz, while frequencies above 125Hz are considered "flicker-free." Although low-voltage LED strips (12V/24V DC) operate on direct current, flicker can still occur due to variations in power supply quality and dimming technologies.
2. Core Causes of Flicker in Low-Voltage LED Strips
（1）.Ripple Interference from Low-Quality Power Supplies
·Inadequate rectification/filtering: Low-cost AC/DC adapters using half-wave rectification introduce 100Hz AC ripple (50Hz mains frequency × 2) into the DC output, directly causing brightness fluctuations.
·Example data: Testing a budget 12V power supply revealed a peak-to-peak ripple of 1.2V (10% of rated voltage), resulting in a flicker index of 0.15 (safety threshold < 0.05).
（2）.Defects in PWM Dimming Technology
·Low-frequency PWM dimming: Some controllers use PWM signals below 200Hz, particularly when dimming below 30% brightness, causing flicker frequencies to drop into the human-sensitive range (e.g., 50–90Hz).
·Harmonic resonance: Multi-channel PWM signals in RGBIC smart LED strips can generate high-frequency harmonics, exacerbating flicker (e.g., resonance between 1kHz primary and 3kHz secondary frequencies).
（3）.Impedance Mismatch in Wiring
·jkjkLong-distance voltage drop: Low-voltage LED strips exceeding 5 meters without power injection experience voltage drop at the far end, causing driver ICs to malfunction and constant-current control to fail, leading to intermittent flicker.
3. Hazards and Detection Methods of Flicker
（1）Physiological and Psychological Effects
·Short-term exposure (>30 minutes): Eye strain, headaches; IALD research shows flicker below 120Hz can increase intraocular pressure by 15%.
·Long-term risks: Accelerated myopia progression in children (flicker disrupts eye focus adjustment) and a threefold increase in seizure risk for epilepsy patients with photosensitivity.
（2）Professional Detection Tools
·Oscilloscope testing: Connect a light sensor to observe brightness waveform frequency and amplitude (must comply with IEEE 1789-2015: fluctuation depth < 8%).
·Smartphone detection: Use a camera app to scan the LED strip; rolling stripes indicate low-frequency flicker (only effective for <500Hz fluctuations).
4. Engineering-Grade Flicker Mitigation Solutions
（1）Hardware Optimization
·High-precision constant-current drivers: Use driver ICs with >60dB ripple rejection ratio (e.g., TI TPS926xx series) to ensure output current fluctuation <1%.
·High-frequency PWM dimming: Upgrade to >3kHz dimming frequency (e.g., DMX512 protocol supports 25kHz) to avoid human perception range.
（2）System Design Principles
·Dual-end power supply + injection points: Inject power every 5 meters to maintain stable voltage and prevent flicker from voltage drop.
·Independent circuit control: Separate wiring for RGBW channels to minimize PWM signal interference.
（3）End-User Purchasing Recommendations
·Certification labels: Prioritize products with "flicker-free certification" (e.g., TÜV Flicker Free) or compliance with IEC/TR 61547-1 standards.
·On-site verification: Use smartphone cameras for quick screening or request flicker waveform test reports from manufacturers.
5. Future Trends: From Passive Elimination to Active Suppression
Post-2025, smart low-voltage LED strips are adopting hybrid dimming technology (combining PWM and constant current reduction, CCR) to achieve 0.1%–100% seamless dimming with a flicker index < 0.01. Concurrently, adaptive filtering power supplies (e.g., GaN gallium nitride solutions) can reduce ripple to below 0.5%, eliminating flicker entirely.
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