Photoelectric Sensor Circuit for High-Frequency Light Rejection
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Solution Overview
Problem
Conventional photoelectric sensors fail to effectively resist high-frequency light interference, leading to signal misjudgment and abnormal phenomena, and traditional solutions cannot meet the increasing requirements of industrial automation for longer detection distances and higher sensitivity, resulting in output jitter or blocking.
Innovation Solution
A photoelectric sensor design featuring a transmitting tube, double receiving tubes, a band-pass filter circuit, a differential amplifier, and a control module that sets different hysteresis errors for various ranges, along with a sensor hysteresis error setting system, which filters out high-frequency interference signals and adjusts hysteresis error dynamically based on range signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a narrow gap with opaque cover is added to block ambient light, then ambient light interference is reduced, but desired signals are blocked and detection range is attenuated
Solution Approach 1:
The patent changes the temporal characteristics of the optical signal by using modulation. The transmitting tube modulates the laser light source at a specific frequency, and the receiving circuit is tuned to detect only this modulation frequency. This allows the system to distinguish desired signals from ambient light interference based on frequency parameters rather than spatial filtering, thus maintaining detection range while resisting interference.
Solution Approach 2:
The patent employs periodic modulation of the optical signal at a specific frequency. The transmitting tube emits modulated optical signals with periodic variations, and the receiving circuit is designed to detect these periodic signals. This periodic action allows the system to filter out non-periodic ambient light interference while maintaining sensitivity to the desired periodic signal, thus preserving detection range.
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 provides enhanced resistance to high-frequency light interference, ensuring stable and reliable operation, wider application range, and optimal hysteresis error settings for different ranges, preventing output jitter and enabling reliable automated production.
Implementation Method 1
a band-pass filter circuit coupled to the double receiving tubes
Implementation Method 2
a differential amplifier coupled to the band-pass filter circuit
Implementation Method 3
a transmitting tube for transmitting laser light source as modulated optical signals
Implementation Method 4
double receiving tubes for receiving optical signals
Data Source
AI summary
The disclosure provides a photoelectric sensor capable of resisting high-frequency light interference. It comprises a transmitting tube, double receiving tubes, a filter arranged at the front ends of the double receiving tubes for filtering optical signals, a band-pass filter circuit coupled to the double receiving tubes, a differential amplifier coupled to the band-pass filter circuit, a control module for controlling the synchronous receiving of optical signals, and a sensor hysteresis error setting system for improving the anti-interference performance of sensors; the control module further collects and obtains ambient light interference signals and sets an interference signal threshold value, and when it is detected that the amplitude of the collected ambient light interference signals is larger than the set interference signal threshold value, the control module discards the light signals lower than the interference signal threshold value after the interference signals are overlaid.