Technical Core and Anti-Interference Design Analysis of FGYD18 Series Background Suppression Photoelectric Sensors

Abstract: This paper delves into the working principles of Fuwei Electronics' FGYD18 series background suppression photoelectric sensors. It focuses on how the coated filter lens, multi-layered protection circuitry, and background suppression algorithm work in concert to achieve stable, reliable, and high-precision detection, providing core sensing assurance for industrial automation systems.

In industrial automation, sensor stability and precision directly determine system performance. With its exceptional design, Fuwei Electronics' FGYD18 series background suppression photoelectric sensors have become the preferred choice for numerous high-end applications. This paper provides an in-depth analysis of its underlying technical core.

I. Background Suppression Principle and Color-Independent Detection

Conventional reflective sensors are highly susceptible to detection distance variations influenced by target color and material, particularly experiencing steep distance decay when detecting dark objects. The FGYD18 series employs Background Suppression technology. Utilizing specialized internal optical components and triangulation principles, it does not merely receive reflected light intensity. Instead, it calculates the position of the light spot to determine the presence of an object. This enables it to effectively ignore background interference and precisely lock the detection focus at a preset distance. Consequently, it achieves nearly consistent detection distances for black, white, or other colored objects, significantly enhancing detection reliability and consistency.

II. Coated Filter Lens and Enhanced Anti-Interference Design

Industrial environments are rife with interference sources such as ambient stray light and electromagnetic noise. The FGYD18 series incorporates a coated filter lens at its optical front end. Crafted from quartz material with excellent thermal stability, this lens effectively filters out interfering light beyond the visible spectrum—such as infrared light—while allowing only the specific wavelengths of the sensor's light source to pass through. This significantly reduces environmental light interference, ensuring signal purity and accuracy. Combined with optimized internal circuit design, it delivers outstanding electromagnetic interference (EMI) resistance, maintaining stable operation even near high-interference equipment like frequency converters and motors.

III. Comprehensive Electrical Protection and Stability Design

To ensure survivability in complex industrial power grids, this series of high-precision photoelectric sensors incorporates multiple built-in protection mechanisms:

Short-Circuit and Overload Protection: Upon detecting unexpected short circuits or excessive loads at the output terminals, the protection circuit instantly activates to cut off the output, preventing damage to the sensor itself and downstream connected devices (e.g., PLC input points).

Reverse Polarity Protection: Withstands incorrect power supply polarity connection without damage, preventing failures and losses caused by wiring errors.

12-24V Wide Input Voltage Range: Compatible with standard industrial DC power supply voltages, ensuring robust adaptability without concerns over voltage fluctuations.

The FGYD18 series is more than a simple switch—it is a highly reliable solution integrating advanced optical design, precision electronics, and rugged protection. Its high-precision photoelectric sensing capabilities stem from meticulous attention to every technical detail. For engineers pursuing zero-error production and high equipment reliability, choosing the FGYD18 means selecting a solid and dependable “foundation of perception” for your automation system.