Iyi niyo ngingo yambere mubice bibiri. Iyi ngingo izabanza kuganira bwa mbere amateka nibibazo byaUbushyuhe bushingiye ku bushyuheSisitemu yo gupima, kimwe no kugereranya kwabo hamwe no kurwanya Teromémetero (Rtd) Ingano yo gupima ubushyuhe. Bizasobanura kandi guhitamo Thermistor, ubucuruzi bwiboneza, hamwe n'akamaro ka Sigma-delta analog-to-digital ihinduka (ADCs) muriyi gace gasaba. Ingingo ya kabiri izasobanura uburyo bwo kunoza no gusuzuma sisitemu yanyuma ya Thermistor.
Nkuko byasobanuwe mu ngingo ibanza, uburyo bwo guhitamo RTD sensor sisitemu, RTD ni umurwanya imyigaragambyo yo kurwanya ubushyuhe. Abakunzi bakora kimwe na btds. Bitandukanye na rtds, zifite ubushyuhe bwiza gusa, umubomu ushobora kugira ubushyuhe bwiza cyangwa bubi. Ubushyuhe bukomeye (NTC) bugabanya imbaraga zabo mugihe ubushyuhe bwabo buzamutse, mugihe ubushyuhe bwiza bwa chies (PTC) byongera kurwanya ubushyuhe buva. Ku gishushanyo. 1 yerekana igisubizo giranga NTC na PTC Thermistors kandi ikabagereranya na RTD umurongo.
Ku bijyanye n'ubushyuhe, umurongo wa rtd ni hafi umurongo, na sensor itwikiriye ubushyuhe bwinshi kuruta Thrmistors (mubisanzwe -200 ° C kugeza kuri + 850 ° kubera imiterere idahwitse (exponential) imiterere ya Thermistor. Ubusanzwe busanzwe butangwa muburyo buzwi buzwi cyane, mugihe umukunzi wa tranrmustor aratandukanye nuwabikoze. Ibi tuzabiganiraho muburyo burambuye mugice cya Thermustor gihuza iyi ngingo.
Abahembo bakozwe mubikoresho bisanzwe, mubisanzwe ceramics, polymers, cyangwa semicondu imibare (mubisanzwe ibyuma byicyuma (mubisanzwe ibyuma byicyuma) nibishanga byiza (Platinum, nikel). Abakunzi barashobora kumenya ubushyuhe buhinduka byihuse kuruta rtds, bitanga ibitekerezo byihuse. Kubwibyo, abakunzi bakunze gukoreshwa na sensor mubisabwa bisaba ikiguzi gito, ingano ntoya, kumva ubushyuhe bwihuse, nko kugenzura amashanyarazi, cyangwa kubaka ubushyuhe bwa siyansi, cyangwa amashami akonje, cyangwa kwishyuza ubukonje intego. Porogaramu.
Mubihe byinshi, mtc thermators ikoreshwa mugupima ubushyuhe bwuzuye, ntabwo ari pTC thermistors. Bamwe muri PTC tremistors barahari bishobora gukoreshwa mumirongo irenze urugero cyangwa nkuko bisubizwa ibicuruzwa bya porogaramu zumutekano. Kurwanya ubushyuhe bwa PTC TheRmistator yerekana akarere gato ka NTC mbere yo kugera kubintu (cyangwa Curie Point), hejuru aho imyigaragambyo ihamye cyane mubunini bwa selisiyusi. Mubihe bikabije, PTC Thermistor izabyara gushyuha mugihe ubushyuhe bukabije, kandi kurwanya bizamuka bizamuka bikabije, bityo bikagabanya ibyinjijwe muri sisitemu, bityo bikarinda ibyangiritse. Guhindura ingingo ya PTC Ubuvuzi bwa PTC busanzwe hagati ya 60 ° C na 120 ° C kandi ntabwo ikwiriye kugenzura ibipimo byubushyuhe muburyo butandukanye. Iyi ngingo yibanze kuri thermistors, ishobora gupima cyangwa gukurikirana ubushyuhe buva kuri -80 ° C kugeza kuri 150 ° C. NTC Thermistors ifite amanota yo kurwanya kuva kuri Ohms nkeya kugeza 10 Mω kuri 25 ° C. Nkuko bigaragara ku gishushanyo. 1, impinduka mu kurwanya imiseli ya selisibu kugirango Abanyamboruzi zimenyerewe kuruta kurwanya Trarmometero. Ugereranije na thermistors, ubukana bwa Thermustor hamwe nagaciro gakomeye koroshya imizunguruko, kubera ko abakunzi basaba kwinjiza inshinge zidasanzwe, kuko ari insimbi zidasanzwe, nka 3-insinga cyangwa 4-insinga 3, kugirango yishyure abarwanya. Igishushanyo cya Thermistor gikoresha iboneza ryuzuye 2.
Gupima ubushyuhe bukomeye bushingiye ku bushyuhe busaba gutunganya ibimenyetso bisobanutse, analogi-to-digitali ihinduka, imiyoboro, n'indishyi, nkuko bigaragara ku gishushanyo. 2.
Nubwo urunigi rwikimenyetso rusa nkaho rworoshye, hari ibintu byinshi bigoye bigira ingaruka ku bunini, ikiguzi, n'imikorere nyayo. Precision ya Adi Portfolio ikubiyemo ibisubizo byinshi byinjijwe, nka AD712-4 / AD7124-8, itanga inyungu nyinshi kubushyuhe bwa sisitemu yinyubako ikenewe kugirango yinjijwe. Ariko, hariho imbogamizi zitandukanye mugushushanya no gutegura ibisubizo byubushyuhe bwa Tormillesor.
Iyi ngingo ivuga kuri buri kibazo kandi itanga ibyifuzo byo kubikemura no koroshya inzira yo gushushanya kuri sisitemu.
Hariho ubwoko butandukanyeNTC ThermistorsKu isoko uyumunsi, guhitamo rero Thermistor iburyo kugirango ibyifuzo byawe birashobora kuba umurimo utoroshye. Menya ko abakunzi bashyizwe ku rutonde n'agaciro kabo, aribwo kurwanya nominal yabo kuri 25 ° C. Kubwibyo, umukunzi wa 10 arwanya izina rya 10 Kω kuri 25 ° C. Abakunzi bafite izina ryizina cyangwa shingiro ryibanze kuva kuri ohms nkeya kugeza 10 mω. Abakunzi bafite amanota yo kurwanya hasi (kurwanya nominal yo kurwanya 10 kω cyangwa munsi yayo mubisanzwe ashyigikira ubushyuhe bwo hasi, nka -50 ° C kugeza kuri + 70 ° C. Abakunzi bafite amanota yo kurwanya hejuru barashobora kwihanganira ubushyuhe bugera kuri 300 ° C.
Ikintu cya Thermistor gikozwe mubisama. Abakunzi baboneka mumipira, radial na smd. Amasaro ya Thermistor ni epoxy yapakiye cyangwa ikirahure gisigaye cyo kurindwa. Epoxy yahitanye umupira wamaguru, abakunzi ba radiyo kandi hejuru birakwiriye ubushyuhe bugera kuri 150 ° C. Ibirahure by'ikirahure birakwiriye gupima ubushyuhe bwo hejuru. Ubwoko bwose bwibikote / gupakira kandi birinda ruswa. Abahembo bamwe bazagira kandi inyongera yo kongera kurinda ibidukikije bikaze. Amabati ya Beadrmustors afite igihe cyihuse kuruta radiyo / smd thermistors. Ariko, ntabwo bararamba. Kubwibyo, ubwoko bwa tranrmustor yakoresheje biterwa nibisabwa byanyuma nibidukikije aho umurambo uherereye. Guhagarara igihe kirekire kuri thermustor biterwa nibikoresho byayo, gupakira, no gushushanya. Kurugero, Thermistor ya Epoxy-NTC irashobora guhindura 0.2 ° C kumwaka, mugihe Thermistator ihinduka 0.02 ° CUmwaka.
THEMMiSTOSS iza muburyo butandukanye. Abaganga basanzwe mubisanzwe bafite ukuri kwa 0.5 ° C kugeza 1.5 ° c. Igipimo cyo Kurwanya Thermistor na Beta agaciro (igipimo cya 25 ° C kugeza 50 ° C / 85 ° C) kugira icyo uhanganira. Menya ko beta agaciro ka THEMMITOR iratandukanye nuwabikoze. Kurugero, the cormertors 10 kω ntc baturutse kubakora bitandukanye bazagira indangagaciro za beta. Kubisobanuro byinshi, abakunzi ba Omega ™ Urukurikirane rwa 47XXX rushobora gukoreshwa. Bafite ukuri 0.1 ° C cyangwa 0.2 ° C hejuru yubushyuhe bwa 0 ° C kugeza 70 ° C. Kubwibyo, ubushyuhe bushobora gupimwa kandi ukuri gusabwa hejuru yubushyuhe bugena niba abakunzi bakwiriye iyi porogaramu. Nyamuneka menya ko hejuru yukuri kwa Omega 49xxx, hejuru yikiguzi.
Guhindura kurwanya dogere selius, gakondo ya beta isanzwe ikoreshwa. Agaciro ka Beta bigenwa no kumenya amanota abiri yubushyuhe hamwe no kurwanya ihuye kuri buri bushyuhe.
RT1 = Kurwanya ubushyuhe 1 RT2 = Kurwanya ubushyuhe 2 T1 = Ubushyuhe 1 (K) T2 = ubushyuhe 2 (k)
Umukoresha akoresha agaciro ka Beta yegereye ubushyuhe bwakoreshejwe mumushinga. Abavuga datashestor benshi batondekanya agaciro ka beta hamwe no kwihanganira abantu kuri 25 ° C no kwihanganira guha agaciro ka beta.
Ibitekerezo byumuhungu hamwe nibisubizo byo kurangiza cyane nka Omega 49xxx Koresha Steinhart-Hart Plation Kuringaniza Gelsius. Ikigereranyo cya 2 gisaba abana bitatu a, B, na C, byongeye gutangwa na sensor abakora. Kuberako coefficient ya eneefficient ikoreshwa hakoreshejwe ingingo eshatu zubushyuhe, ikigereranyo cyavuyemo kigabanya ikosa ryatangijwe na linear (mubisanzwe 0.02 ° 0).
A, B na C bahoraga biva mumashusho atatu yubushyuhe. R = Ubudodo bwa Thermistor muri Ohms T = ubushyuhe muri k dogere
Ku gishushanyo. 3 Erekana urwishimiye sensor. Gutwara ibinyabiziga bikoreshwa kuri thermistor kandi hariya bikorwa kumurwanya neza; Kurwanya neza bikoreshwa nkibisobanuro byo gupima. Agaciro k'umugaragaro kagomba kuba karuta cyangwa kangana n'ahantu henshi h'Ubushyuhe bwa Thermistor (bitewe n'ubushyuhe bwo hasi bwapimwe muri sisitemu).
Mugihe uhitamo ibishushanyo mbonera, kurwanya ntarengwa ya Thermistor agomba kongera kwitabwaho. Ibi byemeza ko voltage hirya no hino kuri sensor hamwe no kurwanya inyandiko buri gihe kurwego rwemewe na elegitoroniki. Umurima isoko isaba ubwiherero cyangwa ibisohoka bihuye. Niba Thermiste arwanya cyane ubushyuhe buke bwa gupimwa, ibi bizavamo inzira mike cyane. Kubwibyo, voltage yazungurutse Thermistor ku bushyuhe bwinshi ni nto. Gahunda yo Gutegura Ibyiciro birashobora gukoreshwa mugupima ibipimo byibimenyetso byo hasi. Ariko, inyungu igomba gutegurwa imbaraga kuko urwego rwikimenyetso ruva mubuvuzi butandukanye nubushyuhe.
Ubundi buryo ni ugushiraho inyungu ariko koresha disiki ya Dynamic. Kubwibyo, nkuko urwego rwibimenyetso bihinduka, gutwara agaciro kagaciro karimo imbaraga kugirango voltage yateze imbere thermistor iri mumirongo yibanze yibikoresho bya elegitoroniki. Umukoresha agomba kwemeza ko voltage yateye imbere muburyo bwo kurwanya inyandiko nayo kurwego rwemewe na elegitoroniki. Amahitamo yombi arasaba urwego rwo hejuru rwo kugenzura, gukurikirana buri gihe kugenzura voltage hakurya ya tranrmustor kugirango ibikoresho bya elegitoroniki bishobora gupima ikimenyetso. Hari uburyo bworoshye? Tekereza ku bumenyi bwa voltage.
Iyo DC Voltage ikoreshwa kuri Thermistor, ikigezweho binyuze muri Thermistor mu buryo bwikora mugihe Thermistor ahinduka. Noneho, ukoresheje ibisobanuro bipima aho kuba umwirondoro, intego yacyo ni ukubara urujya n'uruza runyuze muri Thermistor, bityo ukemerera Thermistor Kurwanya Ubujura kubarwa. Kubera ko gufata voltage nabyo bikoreshwa nkibimenyetso bya adc, nta nyungu zisabwa. Umutunganya ntabwo afite akazi ko gukurikirana ndormistage, kumenya niba urwego rwikimenyetso rushobora gupimwa na electronics, no kubara icyo gukora / gufungura inyungu zigomba guhinduka. Ubu ni bwo buryo bukoreshwa muri iyi ngingo.
Niba Therditor afite amanota make yo kurwanya no kurwanya intera, voltage cyangwa kwishima ubungubu birashobora gukoreshwa. Muri iki kibazo, gutwara imodoka ninyungu birashobora gukosorwa. Rero, umuzenguruko uzaba nkuko bigaragara ku gishushanyo cya 3. Ubu buryo buroroshye muribyo birashoboka kugenzura ikigezweho binyuze muri sensor hamwe no kurwanya imenyekanisha ryimbaraga nkeya. Mubyongeyeho, kwishyuza umukunzi biragabanuka.
Gusobanura voltage birashobora kandi gukoreshwa kuri thermistors hamwe nibipimo byo kurwanya hasi. Ariko, umukoresha agomba guhora yemeza ko ikigezweho binyuze muri sensor ntabwo ari hejuru cyane kuri sensor cyangwa gusaba.
Ibisobanuro voltage byorohereza ishyirwa mubikorwa mugihe ukoresheje thermistor hamwe nurutonde runini rwo kurwanya nubushyuhe bunini. Kurwanya nominal binini byizina bitanga urwego rwemewe rwibintu. Ariko, abashushanya bakeneye kwemeza ko ikiriho kiri kurwego rwemewe hejuru yubushyuhe bwose bushyigikiwe na porogaramu.
Sigma-delta ADCS itanga ibyiza byinshi mugihe ushushanya sisitemu yo gupima Thermustor. Ubwa mbere, kubera ko sigma-delta adc yatangaje ibyinjijwe na analog, ibikandagura hanze bizimizwa byibuze kandi gusa icyifuzo nicyo cya rc yoroshye. Batanga guhinduka muburyo bwuyunguruzo no gusohoka gukaraba. Yubatswe-muyungurura digital birashobora gukoreshwa muguhagarika kwivanga mubikoresho byakozwe mubikorwa. Ibikoresho 24-biti nka AD7124-4 / AD7124-8 Gira Imyanzuro Yuzuye ya Bits 21.7, bityo bagatanga imyanzuro minini.
Gukoresha sigma-delta adc byoroshya igishushanyo mbonera cya Thermistor mugihe kigabanya ibisobanuro, sisitemu igura, umwanya wubuyobozi, nigihe cyo ku isoko.
Iyi ngingo ikoresha AD7124-4-4 / AD7124-8 Nka ADC kuko ari urusaku ruto, abambere muri PGA, Byubatswe hamwe na PGA
Utitaye kubimenya ko ukoresha disiki igezweho cyangwa utwara ibipimo bya ratiometrike birasabwa aho voltage ya ensor na sensor voltage ituruka kumutwe umwe. Ibi bivuze ko impinduka zose mubice zishimishije bitazagira ingaruka ku kuntu icyo gipimo cyuzuye.
Ku gishushanyo. 5 Yerekana aho uhoraho kuri Thermustor na Precision RREF, voltage yateye imbere muri rref niwo voltage yerekana umusemuzi.
Umurima uriho ntukeneye kuba umunyakuri kandi birashobora kuba bike nkuko amakosa yose murwego rwaho azakurwaho muriki gice. Mubisanzwe, birambuye bikunzwe hejuru ya voltage kubera ubukana buhebuje hamwe nubuhanga bwurusaku mugihe sensor iherereye ahantu kure. Ubu bwoko bwuburyo bwa Bias bukoreshwa muri btds cyangwa thermistors hamwe nindangagaciro zo kurwanya hasi. Ariko, kuri thermustor hamwe nigiciro cyo kurwanya hejuru no kumva cyane, urwego rwikimenyetso rwakozwe nubushyuhe buzaba imbata, nibyinshi cyane bya voltage. Kurugero, 1 Kω Thermistor afite kurwanya 10 Kω kuri 25 ° C. ATSON ° C, Kurwanya NTC TheRmistor ni 441.117 Kω. The minimum drive current of 50 µA provided by the AD7124-4/AD7124-8 generates 441.117 kΩ × 50 µA = 22 V, which is too high and outside the operating range of most available ADCs used in this application area. Ubushyuhe nabwo bukunze guhuzwa cyangwa buri hafi ya elegitoroniki, ubudahangarwa kuburyo bwo gutwara ibintu ntabwo bisabwa.
Ongeraho ubwenge murukurikirane nkumuzunguruko wa voltage uzagabanya ubungubu binyuze muri thermistor kumugaragaro. Muri ubu buryo, agaciro k'uruhu rwo kurwanya RESE RESE kigomba kuba kingana n'agaciro k'ubushyuhe bwa metero 25 ° C, kugira ngo irwariritse irwariritse ku bushyuhe bwa metero 25 ° C. CE kuri 25 ° C. Mugihe ubushyuhe buhinduka, kurwanya NTC TheRmistor nabwo birahinduka, kandi igipimo cya disiki ya disiki irahinduka kandi igahinduka voltistator kuba irwanya NTC Thermistor ya NTC.
Niba voltage yatoranijwe ikoreshwa muburyo bwa thermistator na / cyangwa rsense ihuye na voltage ya ADC ikoreshwa mugupima, sisitemu yashizwe mubipimo bya adc (Ishusho 7) kugirango ikosa ribi bijyanye na voltage riva kugirango ukubogaho.
Menya ko umuntu wo kurwanya amakuru (voltage) cyangwa umurego wo kurwanywa (Driven) ugomba kwihanganira intangiriro yo kwihanganira no gutembera cyane, nkuko bihinduka bike bishobora kugira ingaruka kuri sisitemu yose.
Mugihe ukoresheje TOMMiSTORSS nyinshi, voltage imwe yoroshye irashobora gukoreshwa. Ariko, buri muboma ugomba kuba ufite umurwanya usobanutse neza, nkuko bigaragara ku gishushanyo. 8. Ubundi buryo ni ugukoresha amafaranga yo hanze cyangwa hasi-yo kurwanya kuri leta, yemerera gusangira kimwe cyo kumurwanya. Hamwe nibi biboneza, buri muboma ukeneye igihe cyo gukemura mugihe cyapimwe.
Muri make, mugihe ushushanya sisitemu yo gupima ubushyuhe-ubushyuhe bushingiye ku bushyuhe, haribibazo byinshi byo guhitamo, gutoranya ibibanza, uburyo butandukanye bwa ADC, nuburyo iboneza muburyo butandukanye bigira ingaruka kuri rusange. Ingingo ikurikira iri murukurikirane isobanura uburyo bwo guhitamo sisitemu yawe ya sisitemu hamwe na sisitemu ya sisitemu yo kugera kubikorwa byawe.
Igihe cya nyuma: Sep-30-2022