I-Tesmistor: konke odinga ukukwazi ukukala izinga lokushisa kumaphrojekthi akho

Izinzwa ezihlukile zokushisa ziye zahlaziywa kwezinye izindatshana. Enye yezinto noma amadivayisi ongawasebenzisa ukukala ukushisa okushiwo yiyona ngqo umshini wokushisa umzimba, ngesiNgisi i-thermistor (i-resistor ezwela ubushushu noma ukumelana nokuzwela kokushisa). Njengoba igama lalo liphakamisa, kusekelwe entweni eguqula ukumelana kwayo nogesi ngokuya ngamazinga okushisa ebekiwe.

Ngale ndlela, ngokusebenzisa ifomula elula, ngokwazi amandla nokuqina lapho kubekwe khona, ukumelana kungahlaziywa thola izinga lokushisa ngokwezinga layo. Kepha ayisetshenziswanga njengenzwa yokushisa kuphela, ingasetshenziswa futhi ukuguqula ezinye izici zesekethe ngokuya ngamazinga okushisa aso, njengengxenye yokuvikela kumanje okweqile, njll.

La uhlobo lwenzwa Lokho ozokusebenzisela iphrojekthi yakho kuzoya ngezidingo onazo. Ezinye izindatshana ezingakuthakazelisa mayelana nezinzwa zokushisa:

• LM35: lokushisa kanye nomswakama inzwa.
• I-DS18B20: inzwa yokushisa yeziphuzo.
• I-DHT22: ngokunemba lokushisa kanye nomswakama inzwa.
• I-DHT11: inzwa yokushisa eshibhile nomswakama.

Isingeniso ku-thermistor

Emakethe ungathola okuningi ama-thermistors nge-encapsulations ehlukene nezinhlobo ezahlukene. Zonke zisekelwe kumgomo ofanayo, impahla yazo ye-semiconductor (i-nickel oxide, i-cobalt oxide, i-ferric oxide, ...) izoguqulwa lapho izinga lokushisa lihluka, ngaleyo ndlela kuguqulwe ukumelana kwangaphakathi.

Izinhlobo

Phakathi kwe izinhlobo ze-thermistor singaqokomisa amaqembu amabili:

• I-NTC (Negative Tempe Coefficient) Thermistor: la ma-thermistors ane-coefficient engalungile yokushisa, njengoba izinga lokushisa landa, ukuhlushwa kwabathwali bokushaja nakho kuyanda, ngakho-ke, ukumelana kwabo kunciphile. Lokhu kuzenza zisebenziseke ukuze zisetshenziswe njenge:
  • Izinzwa zokushisa ezivame kakhulu kumasekethe amaningi njenge-detector yokushisa ephansi, emkhakheni wezimoto ukukalwa kwezinjini, kuma-thermostats edijithali, njll.
  • Ukuqala umkhawulo wamanje, lapho usebenzisa into enokumelana okuphezulu kokuqala. Lapho okwamanje kudlula kubo lapho kuvulwa isifunda, le divayisi iyashisa ngenxa yokumelana okulethayo futhi njengoba izinga lokushisa lenyuka, ukumelana kuzoncipha kancane kancane. Lokhu kuvimbela ukugeleza kwamanje esifundeni ekubeni kuphakame kakhulu ekuqaleni.
• I-PTC (I-Positive Tempe Coefficient) Ama-Thermistors: bangamanye ama-thermistors ane-coefficient enhle yokushisa, anokugxila okuphezulu kakhulu kwe-dopant okunikeza umphumela ohlukile kuma-NTCs. Lokho wukuthi, esikhundleni sokwehlisa ukumelana ngokushisa okwandayo, umphumela ohlukile uvela kuzo. Ngaleso sizathu, zingasetshenziswa njengamafiyuzi ukuvikela amasekethe agcwele ngokweqile, njengesibali sikhathi sokwenza i-demagnetize i-CRT noma i-cathode ray tube display, ukulawula ama-motor wamanje, njll.

Musa ukudida i-thermistor ne I-RTD (Isitholi Sezinga lokushisa Lokumelana)Njengoba ngokungafani nabo, ama-thermistors ANGAKUGUQI ukumelana cishe ngokulingana. I-RTD uhlobo lwe-thermometer yokumelana ukuthola ithempelesha ngokuya ngokwehluka kokuphikiswa komqhubi. Insimbi yalezi (ithusi, i-nickel, i-platinum, ...), uma ifudunyezwa, inesifudumezi esikhulu esishisayo esizosabalalisa ama-electron futhi sinciphise ijubane laso elijwayelekile (lenyusa ukumelana). Ngakho-ke, ukuphakama kwezinga lokushisa, kukhulu ukumelana, njenge-NTC.

Womabili ama-RTD, ama-NTC, nama-PTC ajwayelekile, ikakhulukazi ama-NTC. Isizathu ukuthi bangakwazi ukwenza indima yabo nge usayizi omncane kakhulu nentengo eshibhile kakhulu. Ungakwazi thola ama-thermistors we-NTC njenge-MF52 ethandwayo ngentengo encane ezitolo ezinjenge-Amazon, njenge Ayikho imikhiqizo etholakele., kanye nakwezinye izitolo ezikhethekile ze-elekthronikhi.

Ngokuqondene ne ukukhipha, inezikhonkwane ezimbili kuphela, njengama-resistors ajwayelekile. Indlela yayo yokuyixhuma iyefana neyanoma isiphi isiphikisi, inani lokumelana kuphela ngeke lihlale lizinzile, njengoba kufanele wazi. Ngemininingwane engaphezulu ngamabanga wokushisa amukelwe, amandla aphezulu asekelwayo, njll., Ungathinta imininingwane yei-dahtasheet kwengxenye oyithengile.

Ukuhlanganiswa ne-Arduino

para hlanganisa i-thermistor nebhodi lakho le-Arduino, ukuxhumana bekungeke kube lula. Kudingeka kuphela ukuvumelanisa leyo theory kanye nezibalo zekhodi okufanele uyenze ku-Arduino IDE yakho. Esimweni sethu, ngicabange ukusebenzisa i-NTC thermistor, ikakhulukazi imodeli ye-MF52. Uma kwenzeka usebenzisa enye imodeli ye-thermistor, kufanele uguqule amanani we-A, B no-C ukuwavumelanisa ngokuya nge-equation ye-Steinhart-Hart:

Ukuba Ukushisa okulinganisiwe, I-T0 inani lokushisa kwezemvelo (ungalilinganisa njengoba unentshisekelo, njenge-25ºC), i-R0 kungaba yinani lokumelana ne-thermistor ye-NTC (kithi leyo enikezwe yi-MF52 datasheet, futhi akufanele uyididanise nokumelana engikungeze esifundeni), futhi i-coefficient B noma i-Beta ingatholakala eshidini lobuchwepheshe lomenzi.

El ikhodi ngakho-ke kungaba kanjena:

#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);
}

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