Tesmistor: zvese zvaunoda kuti uzive tembiricha mumapurojekiti ako

Ese akasiyana tembiricha sensors akaongororwa mune zvimwe zvinyorwa. Chimwe chezvinhu kana zvishandiso zvaunogona kushandisa kuyera tembiricha iyi ndizvo chaizvo izvo thermistor, muChirungu thermistor (thermally sensitive resistor kana tembiricha inodzivirira kuramba). Seizvo zita rayo rinoratidzira, rakavakirwa pane chinyorwa chinoshandura kusagadzikana kwayo kwemagetsi zvinoenderana netembiricha yainoiswa.

Nenzira iyi, pachishandiswa fomula yakapusa, uchiziva iyo voltage uye kusimba kwainoiswa, iko kuramba kunogona kuongororwa sarudza tembiricha zvayera zvakaenzana. Asi haisi chete inoshandiswa senge yekushisa tembiricha, inogona zvakare kushandiswa kugadzirisa mamwe maitiro edunhu zvichienderana netembiricha yayo, sechinhu chekudzivirira pakurwisa kwazvino, nezvimwe.

La Sarudzo yenzira yerudzi Izvo zvauchazoshandisa pachirongwa chako zvinoenderana nezvinodiwa iwe. Zvimwe zvinyorwa zvingakufarire nezvema sensors tembiricha:

• LM35: tembiricha uye hunyoro sensor.
• DS18B20: tembiricha yekushisa yezvinwiwa.
• DHT22: chaiyo tembiricha uye humidity sensor.
• DHT11: yakachipa tembiricha uye humidity sensor.

Nhanganyaya kune iyo thermistor

Mumusika unogona kuwana yakawanda ye vanopisa ine akasiyana encapsulations uye emhando dzakasiyana. Ose iwo akavakirwa pamusimboti mumwechete, yavo semiconductor zvinhu (nickel oxide, cobalt oxide, ferric oxide, ...) inozoshandurwa kana tembiricha ichisiyana, nokudaro ichichinja kuramba kwayo kwemukati.

Mhando

Pakati pe thermistor mhando tinogona kusimbisa mapoka maviri:

• NTC (Negative Tembiricha Coefficient) Thermistor: aya ma thermistors ane yakashata tembiricha coefficient, sezvo tembiricha inowedzera, kusangana kwechaji vatakuri kunowedzerawo, nekudaro, kuramba kwavo kwadzikira. Izvi zvinoita kuti zvive zvinoshanda kuti vakwanise kushandiswa se:
  • Tembiricha yekupisa inowanzoitika mumatunhu mazhinji senge inomiririra detector yetembiricha yakadzika, mune yemotokari chikamu chezviyero muma motors, mune edhijithedhi mahedhiyo, nezvimwe.
  • Kutanga limiter yazvino, kana uchishandisa chinhu chine yakakwira yekutanga kuramba. Kana iyo yazvino ichipfuura nepakati pavo kana dunhu rikavhurwa, chishandiso ichi chinopisa nekuda kwekushomeka kwachinopa uye nekuwedzera kwetembiricha, kuramba kunodzikira zvishoma nezvishoma. Izvi zvinodzivirira kuyerera kwazvino kuenda kudunhu kubva pakuve rakakwirira kwazvo pakutanga.
• PTC (Yakanaka Temperature Coefficient) Thermistors: iwo mamwe ma thermistors ane yakanaka tembiricha coefficient, ine yakanyanya yakanyanya dopant kuisa iyo inovapa iyo inopesana mhedzisiro kuNTCs. Ndokunge, pachinzvimbo chekudzikisa kushomeka nekuwedzera tembiricha, zvinopesana zvinoitika mavari. Neichi chikonzero, ivo vanokwanisa kushandiswa se fuses yekudzivirira kuwanda kwemaseketi, sechirevo chekudzora magineti CRT kana cathode ray chubhu kuratidza, kudzora kwazvino mota, nezvimwe.

Usavhiringidze iyo thermistor ne RTD (Kushora Kupisa Detector)Sezvo kusiyana navo, ma thermistors HAASHANDI kushora zvakaringana. RTD rudzi rwekupikisa thermometer yekuona tembiricha zvichibva pakusiyana kwekushomeka kwemufambisi. Iyo simbi yeaya (mhangura, nickel, platinamu, ...), painopiswa, ine kupisa kukuru kwekupisa kunoparadzira maerekitironi uye kudzora yavo yepakati kumhanyisa (inowedzera kuramba). Naizvozvo, iyo yepamusoro tembiricha, inowedzera kuramba, sekune iyo NTC.

Ose maRTD, maNTC, uye maTCC akajairika, kunyanya maNTC. Icho chikonzero ndechekuti ivo vanogona kuita kwavo basa ne diki kwazvo saizi uye mutengo wakachipa kwazvo. Iwe unogona tora maNT thermistors senge anozivikanwa MF52 nemutengo mudiki muzvitoro zvakaita seAmazon, senge Hapana zvigadzirwa zvakawanikwa., pamwe nezvimwe zvitoro zvine hunyanzvi zvemagetsi.

Kana ari pin out, inongova nemapini maviri, sekungofanana neanopikisa. Maitiro ayo ekubatanidza iyo akafanana neayo chero anopikisa, chete kukosha kwekuramba hakugare kwakadzikama, sezvaunofanirwa kuziva kare. Kuti uwane rumwe ruzivo nezve inogamuchirwa tembiricha maseru, iwo akanyanya akatsigirwa voltage, nezvimwewo, unogona kubvunza iyo data yeiyodatasheet yechinhu chawatenga.

Kubatanidzwa naArduino

Para sanganisira thermistor neako Arduino bhodhi, kubatana kwacho hakugone kuve nyore. Izvo zvinongofanirwa kuchinjisa iyo dzidziso uye kuverenga kwekodhi iwe yaunofanirwa kuburitsa mune yako Arduino IDE. Kwedu, ini ndafungidzira kushandiswa kweNTC thermistor, kunyanya iyo MF52 modhi. Muchiitiko chekushandisa imwe thermistor modhi, iwe unofanirwa kusiyanisa tsika A, B uye C kuti uzvigadzirise zvinoenderana neSteinhart-Hart equation:

Kuva T tembiricha yakayerwa, T0 ndiyo tembiricha yekukoshesesa yezvakatipoteredza (unogona kuyera sezvaunoda, senge 25ºC), R0 ndiyo ingangove kukosha kwekuramba kweNTC thermistor (kwatiri isu iyo yakapihwa neMF52 dhatasheet, uye haufanire zvivhiringidze nekushora kwandakawedzera mudunhu), uye coefficient B kana Beta inogona kuwanikwa mune yemuchina pepa rehunyanzvi.

El code saka zvingave sezvizvi:

#include <math.h>
 
const int Rc = 10000; //Valor de la resistencia del termistor MF52
const int Vcc = 5;
const int SensorPIN = A0;

//Valores calculados para este modelo con Steinhart-Hart
float A = 1.11492089e-3;
float B = 2.372075385e-4;
float C = 6.954079529e-8;
 
float K = 2.5; //Factor de disipacion en mW/C
 
void setup()
{
  Serial.begin(9600);
}
 
void loop() 
{
  float raw = analogRead(SensorPIN);
  float V =  raw / 1024 * Vcc;
 
  float R = (Rc * V ) / (Vcc - V);
  
 
  float logR  = log(R);
  float R_th = 1.0 / (A + B * logR + C * logR * logR * logR );
 
  float kelvin = R_th - V*V/(K * R)*1000;
  float celsius = kelvin - 273.15;
 
  Serial.print("Temperatura = ");
  Serial.print(celsius);
  Serial.print("ºC\n");
  delay(3000);
}

Ndinovimba iyi dzidziso yakubatsira iwe ...