Signal conditioning circuit for detecting thickness of yarn

Abstract

The invention discloses a signal conditioning circuit for detecting the thickness of a yarn. The signal conditioning circuit for detecting the thickness of the yarn is poor in self adaptation to different yarns at present. The signal conditioning circuit comprises a numerical control potentiometer control circuit, a direct current zero setting circuit and an instrument amplifier circuit. The numerical control potentiometer control circuit comprises a single chip microcomputer and a numerical control potentiometer, the direct current zero setting circuit comprises a single chip microcomputer, a resistor and a capacitor, and the instrument amplifier circuit comprises three operational amplifiers and seven resistors. The signal conditioning circuit conducts RC filtering on pulse-width modulation (PWM) signals output by the single chip microcomputers, then the PWM signals and signals output by an infrared receiving tube serve as a pair of difference signals to be input in the instrument amplifier circuit with controllable gain, and accordingly the signal conditioning circuit is guaranteed to have intelligent zero setting and an automatic gain adjusting function.

Description

technical field [0001] The invention belongs to the application field of electronic technology, specifically textile electronic technology, and specifically relates to a signal conditioning circuit for yarn thickness detection. Background technique [0002] Electronic yarn clearer is an electronic device used in the textile industry to remove harmful yarn defects and control yarn quality. The application of electronic yarn clearer can not only monitor the working status of the previous process, but also greatly improve the quality and work efficiency of the finished product in the subsequent process. According to different detection principles, electronic yarn clearers can be divided into two types: photoelectric and capacitive. Compared with the capacitive electronic yarn clearer, the photoelectric electronic yarn clearer has the advantage of having little influence on the ambient temperature and humidity. In the traditional photoelectric electronic yarn clearer, the outp...

AI Technical Summary

Problems solved by technology

In the traditional photoelectric electronic yarn clearer, the output signal of the infrared receiving tube is mainly adjusted by a fixed gain amplifier circuit, which limits the detection range of yarn thickness and affects the detection accuracy

On the one hand, changes in the illumination in the environment and flying flowers and dust during the working process of the textile machine will cause the zero position drift of the signal, resulting in frequent missed and multi-cut yarn defects after the electronic yarn clearer has been used for a period of time.

On the other hand, the electronic yarn clearer needs to adapt to the identification of yarn defects of yarns with different counts and twists, and the amplifier circuit with fixed gain cannot realize the self-adaptation of yarn counts.

Although the gain of the amplifier can also be adjusted with a dedicated programmable amplifier (PGA) circuit, the accuracy of the gain adjustment is low, and the cost of the PGA circuit is relatively high

Images