Cov kab lus piav qhia seb lub tshuab hluav taws xob yog dab tsi, ntawm lub hauv paus ntsiab lus twg nws tau teeb tsa, thiab nyob rau thaj chaw twg hom hlau nplaum no siv.
Magnetism
Tej zaum yog ib qho ntawm qhov ua tau zoo tshaj plaws tab sis yooj yim ntawm lub cev tawm tsam yog hlau nplaum. Ntau tshaj li peb txhiab xyoo dhau los, ntau tus kws tshawb fawb ntawm tim Nkij teb chaws thiab Tuam Tshoj thaum ub paub qhov txawv txav ntawm "sib nqus pob zeb".
Nyob rau hauv peb lub sijhawm, koj yuav tsis xav tsis thoob rau leej twg nrog cov hlau nplaum, txawm tias muaj zog tshaj plaws - raws li neodymium. Lawv feem ntau muag raws li trinkets lossis tuaj yeem pom hauv ntau yam khoom siv thiab cov txheej txheem. Txawm li cas los xij, ob peb tus neeg paub tias cov hlau nplaum tseem ceeb npaum li cas rau kev tshawb fawb thiab thev naus laus zis.
Tab sis thaum pib ntawm lub xyoo pua 19th, xws li cov khoom siv hluav taws xob tau tsim. Yog li dab tsi yog electromagnet, nws ua haujlwm li cas thiab nws siv qhov twg? Peb yuav tham txog qhov no hauv kab lus no.
Definition
Ib lub tshuab hluav taws xob yog ib yam khoom tshwj xeeb uas nws lub lag luam tsim cov hlau nplaum thaum muaj hluav taws xob siv rau nws. Feem ntau, electromagnets muaj cov thawj winding thiab cov tub ntxhais uas muaj ferromagnetic zog.
Cov winding feem ntau yog ua los ntawm tooj liab lossis txhuas hlau ntawm ntau yamthickness, yuav tsum tau them nrog rwb thaiv tsev. Tab sis kuj tseem muaj cov khoom siv hluav taws xob ua los ntawm cov khoom siv superconducting. Cov hlau nplaum sib nqus lawv tus kheej yog ua los ntawm cov hlau, hlau-nickel alloys lossis cam khwb cia hlau. Thiab txhawm rau txhawm rau txo qis qhov poob tam sim no, cov hlau nplaum sib nqus yog tsim los ntawm tag nrho cov ntawv nyias nyias. Tam sim no peb paub tias electromagnet yog dab tsi. Cia peb saib yav dhau los ntawm cov cuab yeej siv tau zoo no.
History
Tus tsim ntawm electromagnet yog William Sturgeon. Nws yog nws uas nyob rau hauv 1825 ua thawj cov hlau nplaum. Raws li txoj cai, lub cuab yeej yog ib lub cylindrical piece ntawm hlau nyob ib ncig ntawm uas ib tug tuab insulated tooj liab hlau raug mob. Thaum lub sijhawm hluav taws xob tau dhau los ntawm nws, tus pas hlau tau txais cov khoom ntawm cov hlau nplaum. Thiab thaum cov dej ntws tam sim no cuam tshuam, lub cuab yeej tam sim ntawd poob tag nrho cov hlau nplaum. Nws yog qhov zoo no - hloov mus rau thiab tawm yog tias tsim nyog - uas tso cai rau siv cov khoom siv hluav taws xob hauv ntau qhov chaw thev naus laus zis thiab kev lag luam.
Peb tau txiav txim siab cov lus nug ntawm lub tshuab hluav taws xob yog dab tsi. Tam sim no cia saib nws cov hom tseem ceeb. Lawv muab faib nyob ntawm txoj kev tsim ib qho chaw sib nqus. Tab sis lawv txoj haujlwm tseem zoo li qub.
Views
Electromagnets yog cov hauv qab no:
- Neutral DC. Nyob rau hauv xws li ib tug ntaus ntawv, lub magnetic flux yog tsim los ntawm ib tug ncaj qha hluav taws xob tam sim no dhau los ntawm winding. Qhov no txhais tau hais tias lub zog txaus nyiam ntawm xws li electromagnet txawv nyob ntawm qhov lojtam sim no, thiab tsis yog los ntawm nws cov kev taw qhia nyob rau hauv winding.
- Polarized DC. Qhov kev txiav txim ntawm ib qho electromagnet ntawm hom no yog ua raws li qhov muaj ob qho kev ywj pheej sib nqus fluxes. Yog tias peb tham txog polarizing, ces nws lub xub ntiag feem ntau yog tsim los ntawm cov hlau nplaum tas mus li (tej zaum tsis tshua muaj, cov khoom siv hluav taws xob ntxiv), thiab nws yuav tsum tsim kom muaj lub zog txaus nyiam thaum lub winding tawm. Thiab qhov kev ua ntawm xws li electromagnet nyob ntawm qhov loj thiab kev taw qhia ntawm cov hluav taws xob tam sim no uas txav mus rau hauv winding.
- AC. Hauv cov khoom siv zoo li no, electromagnet coil yog siv los ntawm kev hloov hluav taws xob tam sim no. Raws li, nrog rau qee lub sijhawm, cov hlau nplaum hloov pauv nws cov kev taw qhia thiab qhov loj. Thiab lub zog ntawm kev nyiam sib txawv tsuas yog nyob rau hauv qhov loj, uas yog vim li cas nws "pulses" los ntawm qhov tsawg kawg nkaus mus rau qhov siab tshaj tus nqi nrog ib zaus uas yog ob npaug ntawm qhov zaus ntawm cov hluav taws xob tam sim no uas pub nws.
Peb twb paub peb tus kheej lawm tias lawv yog hom twg. Tam sim no xav txog cov piv txwv ntawm kev siv electromagnets.
Kev lag luam
Tej zaum txhua tus tsawg kawg ib zaug, tab sis pom ntau yam khoom siv xws li nqa electromagnet. Qhov no yog tuab "pancake" ntawm ntau txoj kab uas hla, uas muaj lub zog loj ntawm kev nyiam thiab siv los nqa cov khoom thauj, seem hlau, thiab feem ntau lwm yam hlau. Nws yooj yim nyob rau hauv qhov tseeb hais tias nws yog txaus los tua lub hwj chim - thiab tag nrho cov load yog tam sim ntawd unhooked, thiab vice versa. Qhov no yooj yim heev rau kev thauj khoom thiab tshem tawm.
Txoj kevelectromagnet, los ntawm txoj kev, yog xam los ntawm cov qauv hauv qab no: F=40550∙B^2∙S. Cia peb xav txog nws hauv kev nthuav dav ntxiv. Nyob rau hauv cov ntaub ntawv no, F yog lub zog nyob rau hauv kilograms (kuj kuj ntsuas nyob rau hauv Newtons), B yog tus nqi induction, thiab S yog qhov chaw ua hauj lwm nto ntawm lub ntaus ntawv.
Tshuaj
Raws li thaum xaus ntawm lub xyoo pua 19th, electromagnets tau siv hauv tshuaj. Ib qho piv txwv zoo li no yog cov cuab yeej tshwj xeeb uas tuaj yeem tshem tawm cov khoom txawv teb chaws (hlau shavings, xeb, nplai, thiab lwm yam) ntawm lub qhov muag.
Thiab nyob rau hauv peb lub sijhawm, electromagnets kuj tau siv dav hauv tshuaj, thiab tej zaum ib qho ntawm cov cuab yeej no uas txhua tus tau hnov txog yog MRI. Nws ua haujlwm ntawm lub hauv paus ntawm magnetic nuclear resonance, thiab, qhov tseeb, yog ib qho loj thiab muaj zog electromagnet.
Technique
Tsis tas li ntawd, cov hlau nplaum zoo sib xws tau siv ntau yam txuj ci thiab hluav taws xob, thiab hauv cov khoom siv hauv tsev, piv txwv li, ua cov xauv. Cov xauv zoo li no yooj yim vim tias lawv ceev heev thiab siv tau yooj yim, tab sis tib lub sijhawm nws txaus los de-energize lub tsev thaum muaj xwm txheej ceev - thiab tag nrho cov ntawm lawv yuav qhib, uas yooj yim heev thaum hluav taws kub.
Thiab, tau kawg, kev ua haujlwm ntawm tag nrho cov relays yog raws li cov hauv paus ntsiab lus ntawm electromagnetism.
Raws li koj tuaj yeem pom, qhov no yog cov cuab yeej tseem ceeb uas tau pom daim ntawv thov hauv ntau yam kev tshawb fawb thiab thev naus laus zis.
