I-Tesmistor: yonke into ekufuneka uyazi ukulinganisa ubushushu kwiiprojekthi zakho

Iimvakalelo zobushushu ezahlukileyo ziye zahlalutywa kwamanye amanqaku. Enye yezinto okanye izixhobo onokuzisebenzisa ukulinganisa obu bushushu zichanekile ngokuchanekileyo Isitshisi, kwi-English thermistor (Resistor ethe-ethe okanye ubushushu ukumelana nobushushu). Njengoko igama layo libonisa, isekwe kwimathiriyeli etshintsha ukumelana nombane ngokobushushu obuphantsi kwayo.

Ngale ndlela, kusetyenziswa ifomula elula, esazi amandla ombane kunye nobunzulu bokubekwa kwayo, ukuxhathisa kungahlalutywa misela ubushushu ngokobungakanani bayo. Kodwa ayisetyenziswanga kuphela njengesixhobo sobushushu, inokusetyenziselwa ukutshintsha ezinye zeesekethe ngokusekwe kubushushu bayo, njengesixhobo sokukhusela ngokuchaseneyo ngoku, njl.

La uhlobo lwenzwa Into oza kuyisebenzisela iprojekthi yakho iya kuxhomekeka kwiimfuno onazo. Amanye amanqaku anokubangela umdla malunga namaqondo obushushu:

• LM35: isivamvo lobushushu nokufuma.
• I-DS18B20: isivamvo lobushushu ulwelo.
• I-DHT22Ubushushu obuchanekileyo kunye nesenzi sokufuma.
• I-DHT11Ubushushu obutshiphu kunye nomenzi woluvo.

Intshayelelo kwi-thermistor

Kwimarike unokufumana ezininzi Thermistors ngokudityaniswa okungafaniyo kunye neentlobo ezahlukeneyo. Zonke zisekwe kumgaqo ofanayo, izinto zazo ze-semiconductor (i-nickel oxide, i-cobalt oxide, i-ferric oxide, ...) ziya kutshintshwa xa iqondo lobushushu lihluka, ngaloo ndlela kuguqula ukumelana kwangaphakathi.

Iindidi

Phakathi iintlobo ze-thermistor Singaqaqambisa amaqela amabini:

• I-NTC (ukungalingani kobushushu obubi) iThermistor: ezi thermistors ezinobushushu obungalinganiyo obufanelekileyo, njengoko amaqondo obushushu esonyuka, uxinizelelo lwabathathi bezithuthi nabo bayonyuka, ke ngoko, ukunganyangeki kwabo kuyancitshiswa. Oku kubenza ukuba babenako ukuze bakwazi ukusetyenziswa njenge:
  • Amaqondo obushushu ashushu ahlala rhoqo kwiisekethi ezininzi ezinje ngomtshini wobushushu obuphantsi, kwicandelo leemoto kwimilinganiselo yeinjini, kwii-thermostats zedijithali, njl.
  • Ukuqala komda wangoku, xa usebenzisa izinto ezinokuxhathisa kokuqala. Xa okwangoku kugqitha kubo xa kuvulwa isekethe, esi sixhobo siyatshisa ngenxa yokuxhathisa esikubonisayo kwaye njengoko amaqondo obushushu esiya enyuka, uxhathiso luya kuncipha. Oku kuthintela ukuhamba ngoku ukuya kwisekethe ekubeni ibe phezulu kakhulu ekuqaleni.
• I-PTC (Ubushushu obulungileyo bokuLunga) iiThermistors: Zezinye ii-thermistors ezinobungakanani obuchanekileyo beqondo lobushushu, ezinokugxila okuphezulu kakhulu okunika iziphumo ezichaseneyo nee-NTCs. Oko kukuthi, endaweni yokunciphisa ukuxhathisa ngamaqondo obushushu anyukayo, isiphumo esahlukileyo senzeka kuzo. Ngenxa yeso sizathu, zinokusetyenziswa njengefestile ukukhusela imijikelezo engaphezulu, njengesibali-xesha sokulawula i-CRT okanye i-cathode ray ityhubhu yokubonisa, ukulawula ii-motors zangoku, njl.

Sukuphambanisa i-thermistor kunye ne- I-RTD (Isixhobo sokujonga ubushushu)Kungenxa yokuba ngokungafaniyo nabo, ii-thermistors AKUTSHINTSHI ukumelana phantse ngokulandelelana. I-RTD luhlobo lokuchasa ubushushu ukubona ubushushu ngokusekwe kukunganyanzeleki komqhubi. Isinyithi kwezi (ubhedu, i-nickel, iplatinam, ...), xa ishushu, ine-thermal agitation eya kusasaza ii-elektron kunye nokunciphisa isantya sayo esiphakathi (sonyusa ukuxhathisa). Ke ngoko, kokukhona iqondo lobushushu liphezulu, kokukhona ukuxhathisa, njenge-NTC.

Zombini ii-RTD, ii-NTCs, kunye nee-PTC ziqhelekile, ngakumbi ii-NTCs. Isizathu kukuba banokwenza indima yabo nge isayizi encinci kakhulu kunye nexabiso eliphantsi kakhulu. Unako fumana i-NTC Thermistors njengeMF52 eyaziwayo ngexabiso elincinci kwiivenkile ezinje ngeAmazon, kanye Akukho mveliso ifunyenweyo, nakwezinye iivenkile ezikhethekileyo zombane.

Ngokuphathelele isikhonkwane, inezikhonkwane ezibini kuphela, njengezichasi eziqhelekileyo. Indlela yayo yokuyiqhagamshela iyafana naleyo yokuxhathisa, kuphela lixabiso lokumelana elingenakuhlala lizinzile, njengoko kufanele ukuba sele uyazi. Ngolwazi oluthe kratya kumanqanaba obushushu amkelekileyo, amandla aphezulu axhaswayo, njl.njlishiti yedatha zelo candelo ulithengileyo.

Umdibaniso neArduino

ukuba hlanganisa i-thermistor kunye nebhodi yakho yeArduinoUnxibelelwano alunakuba lula. Kuyimfuneko kuphela ukulungelelanisa ithiyori kunye nokubala kwekhowudi ekufuneka uyivelisile kwi-IDE yakho yeArduino. Kwimeko yethu, ndicinge ukusetyenziswa kwe-NTC thermistor, ngakumbi imodeli ye-MF52. Kwimeko yokusebenzisa enye imodeli ye-thermistor, kuya kufuneka uguqule amaxabiso A, B kunye no-C ukuzilungelelanisa ngokwe-Steinhart-Hart equation:

Ukuba T ubushushu obulinganisiweyo, T0 lixabiso lobushushu bendalo (ungalilinganisa njengoko unomdla, njenge-25ºC), i-R0 iya kuba lixabiso lokumelana ne-NTC thermistor (kwimeko yethu leyo inikezwe yi-MF52 datasheet, kwaye kuya kufuneka ungayiphambanisi nokumelana nendikongeze kwisekethe), kwaye ukungalingani kweB okanye iBeta kunokufumaneka kwiphepha lobuchwephesha lomenzi.

El código kuya kuba njalo:

#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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