Human body infrared thermometer PCBA scheme

Human body infrared thermometer PCBA scheme

During the three-year epidemic, all kinds of places where people flow are equipped with forehead temperature guns, thermometers and other epidemic prevention equipment. Why should such equipment be equipped? In fact, the forehead temperature gun and thermometer can directly measure the body temperature without contacting the human body to avoid the spread of disease. As a necessary thermometer for epidemic prevention, this kind of products has always had a large volume. Although the price and cost are very low now, and although the domestic market is actually approaching saturation, there is still a continuous demand in the foreign market. Because the epidemic prevention policies in foreign countries are different from those in China, they are more open to the outside world. It is very good to have one in the family for continuous monitoring.

At present, some of the human body thermometer solutions PCBA are directly matched with the public model shell of the infrared human body thermometer. Even if there is deviation, the time required for the development of the direct plate modification is very short, and the prototype can be provided within one week for testing. In addition, it has continuously developed and tested hundreds of thermometers and forehead temperature guns, and accumulated many development experiences. Aiming at different software and hardware problems, it has formed a one-stop process of modifying, testing and solving problems, and solved problems in a very short time.

Introduction to product parameters of human body infrared thermometer scheme:

(1) Product composition: infrared thermometer mainly includes infrared sensor, amplifier and signal processor, power supply system, display, buzzer and other auxiliary function modules;

(2) LCD display: backlight LCD display, reading is still clear in the dark environment, and with three colors (red, yellow and green) backlight;

(3) Key control: multiple key control, on / off, temperature measurement and mode conversion; Unit conversion: intelligent conversion of Celsius and Fahrenheit units;

(4) One key temperature measurement: infrared measurement, one key temperature measurement, simple, fast and high accuracy;

(5) Operating environment: - 20 ~ 50 ℃ for normal use;

(6) Shutdown time: 1 minute automatic shutdown without operation, saving power;

(7) Temperature alarm: the alarm temperature can be set freely. If the temperature is abnormal, the buzzer will sound and the display light will turn red;

(8) Unit conversion: intelligent conversion of Celsius and Fahrenheit units;

Finally, the working principle of the infrared thermometer is to focus the infrared energy of the human body on the photodetector and convert it into the corresponding electrical signal. After the signal is amplified and processed by the chip, and corrected according to the built-in algorithm of the thermometer and the target emissivity, it is converted into the temperature value of the measured target and displayed through the LCD. At present, the main control chip of the thermometer is an 8-bit CMOS infrared frontal temperature gun single chip MCU - zhw3548, which has accurate temperature measurement and good quality. In addition, it adopts lqfp48 package and 24 bit ADC with one full differential analog signal input. It has built-in charge pump, built-in voltage regulator for sensor and modulator to better cooperate with thermopile sensor for temperature measurement.