Kutentha Mfundo ya Induction Cooker
Induction cooker imagwiritsidwa ntchito kutenthetsa chakudya potengera mfundo ya electromagnetic induction. Pamwamba pa ng'anjo ya cooker induction ndi mbale ya ceramic yosagwira kutentha. Kusinthasintha kwapano kumapanga mphamvu ya maginito kudzera mu koyilo yomwe ili pansi pa mbale ya ceramic. Pamene mzere wa maginito wa maginito umadutsa pansi pa mphika wachitsulo, mphika wachitsulo chosapanga dzimbiri, ndi zina zotero, mafunde a eddy adzapangidwa, omwe amatenthetsa pansi pa mphika, kuti akwaniritse cholinga chotenthetsera chakudya.
Njira yake yogwirira ntchito ndi motere: magetsi a AC amasinthidwa kukhala DC kupyolera mu rectifier, ndiyeno mphamvu ya DC imasinthidwa kukhala mphamvu yapamwamba ya AC yomwe imaposa ma frequency omvera kudzera pa chipangizo chosinthira mphamvu chapamwamba. Mphamvu ya AC yothamanga kwambiri imawonjezedwa ku coil yotenthetsera yozungulira yozungulira kuti ipange maginito osinthasintha. Mphamvu ya maginito imalowa mu mbale ya ceramic ya chitofu ndikugwira ntchito pa mphika wachitsulo. Mafunde amphamvu a eddy amapangidwa mumphika wophikira chifukwa cha kulowetsedwa kwa electromagnetic. Mtsinje wa eddy umagonjetsa kukana kwamkati kwa mphika kuti amalize kutembenuka kwa mphamvu yamagetsi kuti itenthe mphamvu pamene ikuyenda, ndipo kutentha kwa Joule komwe kumapangidwa ndi gwero la kutentha kwa kuphika.
Kusanthula kwa Circuit of Induction Cooker Working Mfundo
1. Dera lalikulu
Pachithunzichi, mlatho wokonzanso BI umasintha ma frequency amagetsi (50HZ) kukhala voteji ya DC. L1 ndi chotsamwitsa ndipo L2 ndi coil electromagnetic. IGBT imayendetsedwa ndi kugunda kwa rectangular kuchokera ku control circuit. IGBT ikatsegulidwa, zomwe zikuyenda kudzera mu L2 zimakula mwachangu. IGBT ikadulidwa, L2 ndi C21 zidzakhala ndi ma resonance angapo, ndipo C-pole ya IGBT ipanga kugunda kwamphamvu kwambiri pansi. Kugunda kukatsika mpaka zero, kugunda kwagalimoto kumawonjezedwa ku IGBT kachiwiri kuti ipangitse kuyendetsa. Zomwe zili pamwambazi zimazungulira mozungulira, ndipo mafunde akuluakulu amagetsi amagetsi pafupifupi 25KHZ amapangidwa, zomwe zimapangitsa kuti mphika wachitsulo ukhale pansi pa mbale ya ceramic kupangitsa kuti mphikawo ukhale wotentha. Mafupipafupi a resonance amatenga magawo a L2 ndi C21. C5 ndiye capacitor yamagetsi yamagetsi. CNR1 ndi varistor (surge absorber). Mphamvu yamagetsi ya AC ikakwera mwadzidzidzi pazifukwa zina, imakhala yochepa nthawi yomweyo, yomwe imawombera fuseyo mwachangu kuti iteteze dera.
2. Mphamvu zothandizira
Mphamvu yosinthira imapereka mabwalo awiri okhazikika: + 5V ndi + 18V. The + 18V pambuyo kukonzanso mlatho imagwiritsidwa ntchito poyendetsa galimoto ya IGBT, IC LM339 ndi fan drive circuit imafaniziridwa mofanana, ndipo + 5V pambuyo pa kukhazikika kwa voteji ndi dera lokhazikika lamagetsi atatu amagwiritsidwa ntchito poyang'anira MCU.
3. Kuzizira fani
Mphamvu ikayatsidwa, chowongolera chachikulu cha IC chimatumiza chizindikiro cha fan drive (FAN) kuti chiwongolero chizizungulira, kutulutsa mpweya woziziritsa wakunja kulowa m'makina, ndikutulutsa mpweya wotentha kuchokera kumbuyo kwa makina. kuti tikwaniritse cholinga cha kutentha kwa makina, kuti tipewe kuwonongeka ndi kulephera kwa magawo chifukwa cha kutentha kwakukulu komwe kumagwirira ntchito. Faniyo ikayima kapena kutentha kwapang'onopang'ono kumakhala koyipa, mita ya IGBT imayikidwa ndi chotenthetsera kuti chitumize chizindikiro cha kutentha kwa CPU, kusiya kutentha, ndikupeza chitetezo. Panthawi yoyatsa mphamvu, CPU imatumiza chizindikiro chodziwikiratu, kenako CPU imatumiza chizindikiro cha fan drive kuti makinawo azigwira ntchito pomwe makinawo amayenda bwino.
4. Kuwongolera kutentha kosalekeza ndi dera lotetezera kutentha kwambiri
Ntchito yayikulu yaderali ndikusintha kutentha kosinthira voteji kukana malinga ndi kutentha komwe kumamveka ndi thermistor (RT1) pansi pa mbale ya ceramic ndi thermistor (coefficient ya kutentha koyipa) pa IGBT, ndikuitumiza ku main. control IC (CPU). CPU imapanga chizindikiro chothamanga kapena choyimitsa poyerekezera mtengo wa kutentha pambuyo pa kutembenuka kwa A / D.
5. Ntchito zazikulu za main control IC (CPU)
Ntchito zazikulu za 18 pin master IC ndi izi:
(1) Mphamvu ON / OFF kusintha kusintha
(2) Kutentha mphamvu / kutentha kosalekeza
(3) Kulamulira kwa ntchito zosiyanasiyana zodziwikiratu
(4) Palibe kuzindikira katundu ndi kuzimitsa basi
(5) Kuzindikira kolowera kofunikira
(6) Kuteteza kutentha kwakukulu mkati mwa makina
(7) Kuyendera mphika
(8) Chidziwitso cha kutentha kwa ng'anjo pamwamba
(9) Kuzizira kwa mafani
(10) Kuwongolera mawonedwe osiyanasiyana
6. Kwezani dera lodziwikiratu
Muderali, T2 (transformer) imalumikizidwa motsatizana ndi mzere kutsogolo kwa DB (wokonzanso mlatho), kotero kuti voteji ya AC pa T2 yachiwiri ya mbali imatha kuwonetsa kusintha kwakusintha kwapano. Magetsi a AC awa amasinthidwa kukhala magetsi a DC kudzera mu D13, D14, D15 ndi D5 kukonzanso mafunde athunthu, ndipo magetsi amatumizidwa mwachindunji ku CPU kuti atembenuke AD pambuyo pa kugawikana kwamagetsi. CPU imaweruza kukula komwe kulipo molingana ndi mtengo wosinthidwa wa AD, kuwerengera mphamvu kudzera pa pulogalamu ndikuwongolera kukula kwa PWM kuti athe kuwongolera mphamvu ndikuzindikira katundu.
7. Thamangitsani dera
Derali limakulitsa kutulutsa kwa siginecha ya pulse kuchokera kugawo losinthira pulse mpaka mphamvu ya siginecha yokwanira kuyendetsa IGBT kuti itsegule ndi kutseka. Kuchulukira kwa kugunda kwamphamvu, ndikotalikirapo nthawi yotsegulira ya IGBT. Kuchuluka kwa mphamvu ya chophika choyatsira, ndikowonjezera mphamvu yamoto.
8. Synchronous oscillation loop
Dongosolo lozungulira ( jenereta ya jenereta ya sawtooth) yopangidwa ndi lupu yolumikizirana yopangidwa ndi R27, R18, R4, R11, R9, R12, R13, C10, C7, C11 ndi LM339, yomwe ma frequency ake oscillating amalumikizidwa ndi ma frequency ophikira pansi. Kusintha kwa PWM, kumatulutsa kugunda kofananira kudzera pa pini 14 ya 339 kuyendetsa kuti igwire ntchito mokhazikika.
9. Dera lachitetezo cha Surge
Dongosolo lachitetezo cha Surge lopangidwa ndi R1, R6, R14, R10, C29, C25 ndi C17. Kuthamanga kukakwera kwambiri, pini 339 2 imatulutsa mlingo wochepa, kumbali imodzi, imadziwitsa MUC kuyimitsa mphamvu, kumbali ina, imayimitsa chizindikiro cha K kupyolera mu D10 kuti muzimitsa mphamvu ya galimoto.
10. Dynamic voltage detective circuit
Dera lodziwira voteji lomwe limapangidwa ndi D1, D2, R2, R7, ndi DB limagwiritsidwa ntchito kuti lizindikire ngati mphamvu yamagetsi yamagetsi ili mkati mwa 150V ~ 270V CPU itatha kutembenuza mwachindunji mafunde owongolera a AD.
11. Kuwongolera nthawi yomweyo kwamagetsi apamwamba
R12, R13, R19 ndi LM339 amapangidwa. Pamene voliyumu yakumbuyo ili yabwinobwino, derali siligwira ntchito. Pamene voteji yapamwamba iposa 1100V, pini 339 1 idzatulutsa mphamvu zochepa, igwetse PWM, kuchepetsa mphamvu yotulutsa, kulamulira voteji yam'mbuyo, kuteteza IGBT, ndi kuteteza kuwonongeka kwa overvoltage.
Nthawi yotumiza: Oct-20-2022
