In the modern society that advocates environmental protection, people use more natural energy, such as solar energy, wind energy and so on. But when using wind energy, it also needs an instrument to control it, so the wind speed sensor is produced, which is an instrument used to measure the wind speed. For this kind of sensor, some people may be unfamiliar with its working principle and have no clue about its circuit. Therefore, it is necessary for us to learn about the wind speed sensor circuit, and fully understand the wind speed sensor by its circuit.
Wind Speed – Frequency Converter
The wind speed-frequency conversion circuit is the core part of the wind speed sensor, which is mainly composed of a grooved photoelectric switch tube and a uniform perforated disc that rotates with the wind cup.
- Assuming that the center velocity of the center point of the wind cup is v’, the distance from the center of the rotating shaft to the center of the wind cup is R, and the wind cup rotates n times per second, then v’=2πR*n
- Assuming the wind speed is v, let k=v/v’, k is the wind speed conversion coefficient, which can be obtained through wind tunnel experiments, then: v=k*v’=k*2πr*n
- Assuming that the number of apertures on the light-shielding disc is a, then after the slot-type photoelectric switch tube is applied with normal voltage, every time the aperture disc rotates from the middle of the photoelectric switch tube for one cycle, a ten pulse will be generated, so the wind speed—— The frequency of the output pulse of the frequency conversion circuit is: f=a*n=a/(2πk*R)*v
Obviously the output pulse frequency is proportional to the wind speed signal. In practical applications, the value is generally several tens, and the sensitivity of the “wind speed-frequency converter” can be improved by adjusting the distance between the rotating shaft and the center of the wind cup.
Frequency-Voltage Conversion Circuit
The function of the wind speed sensor is to convert the wind speed signal into a voltage signal output. Therefore, the pulse signal output by the photoelectric switch must be converted into a voltage signal through the F/V converter. The relationship between the output voltage V1 and the input pulse frequency is: Vo=K*Vcc*R2*C2*f
If an A/D converter and a display circuit are added to the output end of the F/V converter, it is convenient and convenient to form an anemometer. After a little improvement, this circuit can also be used as a speed sensor in an automatic speed control system, and its performance can exceed that of a tachogenerator. The circuit of the wind speed sensor looks complicated, but it is actually very well understood. Through the circuit of the wind speed sensor, we can fully understand its working principle and how it measures the wind speed. This measurement method also changes the previous wind speed. The measurement method makes the measurement of wind speed safer and more accurate. It also allows us to have a certain understanding of the wind speed sensor, and know how to use the wind speed sensor in our daily life, so as to achieve value for money and use it.