Yuav Paub
- Fais fab resistors yog siv nyob rau hauv electronics kom dissipate zog los ntawm kev tswj tam sim no ntws thiab voltage.
- Qhov ntsuas lub zog ntawm tus resistor txhais tau hais tias lub zog ntau npaum li cas tus resistor tuaj yeem ua tau zoo ua ntej nws pib raug kev puas tsuaj mus tas li.
- Cov ntawv thov hluav taws xob feem ntau siv cov hluav taws xob qis, feem ntau 1/8th watt lossis tsawg dua. High-power resistors raug ntsuas ntawm 1 watt lossis zoo dua, suav nrog ntau kilowatt.
Kab lus no piav qhia seb cov resistors ua haujlwm li cas thiab suav nrog saib ntau hom resister.
Power Resistor Basics
Lub hwj chim dissipated los ntawm ib tug resistor tuaj yeem pom siv Joule thawj txoj cai (Power=Voltage x Current). Lub zog dissipated yog hloov mus rau cua sov thiab nce qhov kub ntawm qhov resistor. Qhov kub ntawm lub resistor nce mus txog thaum nws mus txog qhov chaw uas cov cua sov tau tawm hauv huab cua, lub rooj tsav xwm hauv Circuit Court, thiab ib puag ncig ib puag ncig sib npaug cov cua sov tsim tawm.
Nyob ntawm qhov xav tau wattage, lub cuab yeej yuav xav tau lub zog hluav taws xob tiv thaiv kom tsis txhob kub dhau. Ua kom qhov kub ntawm qhov resistor qis yog qhov tsim nyog los tswj cov dej ntws ntau dua yam tsis muaj kev puas tsuaj lossis kev puas tsuaj.
Kev ua haujlwm ntawm lub zog tiv thaiv siab tshaj nws lub zog ntsuas thiab qhov kub thiab txias tuaj yeem ua rau muaj qhov tshwm sim hnyav, suav nrog kev hloov pauv ntawm tus nqi tsis kam, txo qis kev ua haujlwm, qhib circuits, lossis hluav taws xob hluav taws xob. Txhawm rau kom tsis txhob muaj qhov ua tsis tiav, lub zog resistors feem ntau derated raws li kev xav tau ntawm kev ua haujlwm.
Fais fab resistors feem ntau loj dua lawv cov khoom sib xws. Qhov loj me tuaj yeem pab kom cov cua sov dissipate thiab feem ntau yog siv los muab kev xaiv mounting rau heatsinks. High-power resistors kuj muaj nyob rau hauv cov pob hluav taws-retardant kom txo tau qhov kev pheej hmoo ntawm kev ua tsis zoo.
kab hauv qab
Cov ntawv thov hluav taws xob feem ntau siv cov hluav taws xob qis, feem ntau 1/8th watt lossis tsawg dua. Txawm li cas los xij, cov ntawv thov xws li cov khoom siv hluav taws xob, lub zog nres, lub zog hloov pauv, lub suab nrov, thiab cov cua sov feem ntau xav tau cov hluav taws xob siab. Feem ntau, high-power resistors raug ntsuas ntawm 1 watt lossis ntau dua. Qee qhov muaj nyob rau hauv ntau kilowatt.
Power Resistor Derating
Qhov ntsuas wattage ntawm lub zog hluav taws xob tau teev nyob rau ntawm qhov kub ntawm 25C. Raws li qhov kub ntawm lub hwj chim resistor nce siab tshaj 25C, lub zog uas tus resistor tuaj yeem tswj tau zoo pib poob. Txhawm rau kho qhov kev xav tau ntawm kev ua haujlwm, cov tuam ntxhab muab daim ntawv qhia derating. Daim ntawv derating no qhia tau hais tias muaj zog npaum li cas tus resistor tuaj yeem ua raws li qhov kub ntawm qhov resistor nce.
Txij li 25C yog qhov ntsuas kub hauv chav, thiab txhua lub zog uas tau tawg los ntawm lub zog hluav taws xob ua kom sov, khiav lub zog hluav taws xob ntawm nws cov ntsuas hluav taws xob feem ntau nyuaj. Txhawm rau suav rau qhov cuam tshuam ntawm kev khiav hauj lwm kub ntawm cov resistor, manufacturers muab lub hwj chim derating nkhaus los pab cov tsim kho rau cov kev txwv ntawm lub ntiaj teb tiag. Nws yog qhov zoo tshaj plaws los siv lub zog derating nkhaus raws li cov lus qhia thiab nyob hauv thaj chaw ua haujlwm tau pom zoo. Txhua hom resistor muaj qhov sib txawv derating nkhaus thiab sib txawv qhov siab tshaj plaws kev ua haujlwm siab.
Ntau yam sab nraud tuaj yeem cuam tshuam rau lub zog derating nkhaus ntawm tus resistor. Ntxiv cov cua txias txias, lub heatsink, los yog cov khoom siv zoo dua los pab kom cov cua sov tawm los ntawm cov resistor tso cai rau nws los tuav lub zog ntau dua thiab tswj qhov kub thiab txias. Txawm li cas los xij, lwm yam ua haujlwm tiv thaiv kev ua kom txias, xws li lub thawv ntim kom cov cua sov tsim nyob rau hauv ib puag ncig, cov khoom tsim hluav taws xob nyob ze, thiab ib puag ncig xws li av noo thiab qhov siab.
Hom Cov Hluav Taws Xob Hluav Taws Xob
Txhua hom hluav taws xob resistor muaj peev xwm sib txawv rau cov ntawv thov sib txawv. Wirewound resistors, piv txwv li, tuaj nyob rau hauv ntau yam ntawm daim ntawv, nrog rau nto-mount, radial, axial, thiab chassis-mount tsim rau kev pom cua sov dissipation. Tsis yog-inductive wirewound resistors kuj muaj rau cov ntawv thov hluav taws xob siab. Rau cov ntawv thov muaj zog heev, xws li dynamic braking, nichrome hlau resistors yog qhov zoo tagnrho, tshwj xeeb tshaj yog thaum lub load yuav tsum muaj ntau pua lossis ntau txhiab watts. Nichrome hlau resistors kuj tseem siv tau los ua cov khoom cua sov.
hom resistors muaj xws li:
- Wirewound resistors
- Cement resistors
- Zaj duab xis resistors
- Metal film
- Carbon composite
- Nichrome hlau
Ntau hom resistor tuaj yeem ua ntau yam xws li:
- DPAK resistors
- Chassis-mount resistors
- Radial (sawv) resistors
- Axial resistors
- Nto-mount resistors
- Ntawm-qhov resistors
