An Automatically Adjustable Photoelectric Sensor Signal Circuit Based on Feedback System

Abstract

The invention relates to an automatic adjustment photoelectric sensor signal circuit based on a feedback system. A controller is connected to an LED driving circuit which drives a light emitting device to emit light. One side of the light emitting device is provided with a light receiving sensor. A light blocking device is arranged between a light receiving device and the light receiving sensor. After the light receiving sensor senses the light reflected by a wounded part, signal current is generated and is processed by a sensor signal processing circuit, a feedback circuit feeds a signal to a controller, and the controller adjusts the LED driving circuit according to the feedback signal to control the brightness of the light emitting device. According to the automatic adjustment photoelectric sensor signal circuit, through connecting the feedback circuit behind the light receiving sensor, the real-time adjustment can be carried out according to various environmental temperature changes in concrete detection, thus accurate data is measured, few peripheral devices are employed, the quality of a sensor output effective signal can be greatly improved, and the automatic adjustment photoelectric sensor signal circuit is adapted to measurement requirements in different environments.

Description

technical field [0001] The invention relates to an automatically adjustable photoelectric sensor signal circuit based on a feedback system, which belongs to the application field of electronic circuits. Background technique [0002] The application of photoelectric sensors to detect the parameters of human body signs has become more and more popular. With the development of technology, its application has become more and more extensive. A light wave is emitted by a light-emitting device to irradiate the surface of skin or other biological tissues. Depending on the parameters that light waves can penetrate or absorb, the light sensor is used to receive the reflected signal, and by analyzing the signal's intensity components and other information, it can now be used to detect heart rate, participate in blood pressure assessment, blood oxygen calculation, blood sugar assessment, etc. And many more practical biological sign detection applications. [0003] The reflective photoe...

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Problems solved by technology

[0004] However, the existing applications do not introduce a feedback loop to adjust the sensor's measurement signal circuit, resulting in the inability to adapt to the needs of measurement in different environments

For example, in the application of measuring the pulse signal of the human body with a photoelectric sensor, if the sensor is attached to the finger for measurement, if the temperature of the fingertip is very low and the blood flow is very weak, if it still outputs the same light as when the finger is warm If it is strong, it is difficult for the sensor to detect a valid pulse signal, resulting in measurement errors

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