Ntau tshaj qhov kuv xav. Kuv yuav tsum paub cov khoom no!
USB chaw nres nkoj fais fab specifications txawv ntawm 100mA rau 1.5A (thiab ntau dua rau hom C chaw nres nkoj), tab sis cables thiab connectors tsis. Lawv ib txwm ntsuas ntawm 1.8A, uas yog txhua yam koj nyiam ntawm no. Qee lub hwj chim dongles muab ntau dua tam sim no vim tias lawv tuaj yeem "tawm nrog nws" ... lossis yog li lawv xav.
Tab sis qhov kev ntsuam xyuas no yog ua raws li kev txwv kev nyab xeeb rau kev tiv thaiv cua sov ntawm cables thiab connectors. Tsis muaj kev lees paub tshwj xeeb, yog tias kuv ntsaws ntxiv 5V ntawm 1.5A rau hauv USB Hom A txuas, Kuv paub tseeb tias yuav tau ntxiv 5V ntawm ze rau 1.5A los ntawm Hom B lossis Micro B kawg ntawm cov kab ntawd. Cov cables / connectors tsuas yog ntsuas los tuav cov cua sov kom ntseeg tau tias lawv tsis yaj. Qhov tseeb, feem ntau specs xyuas kom meej tias tsis muaj dab tsi hnov suab sov so rau qhov kov.
Ua cas koj ua npaws? Ntev nyob qhov tsis kam! Txhua lub xaim uas tsis yog superconductor muaj qee yam tsis kam. Ohm txoj cai qhia rau koj tias IE=IR, qhov twg E yog voltage, kuv yog tam sim no, thiab R yog tsis kam. Yog li thaum kuv muab lub zog los ntawm ib lub xaim, qhov tam sim no x tsis kam muab qhov hluav taws xob uas yuav "siv" ntawm cov xaim, piv txwv li cov hluav taws xob hluav taws xob uas tig mus rau hauv tshav kub thiab yog li tsis tau mus rau koj lub xov tooj.
Nyeem tsab xov xwm no tam sim no vim nws muaj cov lus teb koj tab tom nrhiav, yog tias tsis yog tag nrho cov lus piav qhia: USB cable tsis kam: vim li cas koj lub xov tooj / ntsiav tshuaj yuav tau them qeeb. Qhov hluav taws xob poob thoob plaws lub cable yeej cuam tshuam rau lub sijhawm them. Lub ntsuas ntawm lub hwj chim coj (qhov tuab ntawm cov xaim, uas txiav txim siab qhov tsis kam ntawm ib chav tsev ntev) thiab qhov ntev ntawm lub cable tuaj yeem ua rau lub sijhawm them nyiaj ntev dua.
roj teeb them hom
Interestingly, lub USB 2.0 roj teeb them specification yuav tsum tau ib txwm ntxiv 5V thiab tsawg kawg yog 1.5A. Txoj kev tshawb no tsis siv qhov ntsuas 1.5A, tab sis lawv tau saib 2.0A thiab 2.4A, uas yog qib qee cov tuam txhab thov. Tab sis tej zaum lawv yeej tsis tau txais lawv, ntawm no yog vim li cas.
Lub hauv paus rau lub roj teeb them hom yog tias USB chaw nres nkoj tuaj yeem muab lub zog ntau dua, thiab dua, cov khoom siv hluav taws xob yuav tsum muab tsawg kawg 1.5A ntawm tam sim no ntawm nws tus pin tso zis. Tej zaum nws yuav los yog tsis muaj peev xwm muab tau ntau dua. Lub tshuab tswj fais fab, suav nrog cov roj teeb chargers, yuav tsum ntse yuav luag txhua lub sijhawm. Piv txwv li, nws tsuas tuaj yeem kos 500mA thaum nyob ntawm qhov chaw nres nkoj cov ntaub ntawv. Yog li cov txheej txheem them nyiaj tau zoo heev rau cov khoom siv.
Nyob rau hauv lub roj teeb them hom, lub xov tooj txo qhov kev thov tam sim no kom txog rau thaum qhov yuav tsum tau muaj voltage. Lub zog hluav taws xob ntau dhau yuav pib "crowbar", poob qis tam sim no thiab tsis tshua muaj hluav taws xob tso tawm, yog li txhua lub xov tooj hluav taws xob tswj hluav taws xob hluav taws xob tau tsim los txwv kev kos tam sim no kom tsis txhob muaj qhov hluav taws xob siab tshaj tus nqi qis, tsuas yog los tiv thaiv koj lub hwj chim dongle Tiv thaiv kev puas tsuaj, hluav taws kub. , tej yam me me li ntawd. Los ntawm qhov pom ntawm tus tswj fais fab, lub zog poob ntawm lub cable yog raws nraim tib yam li lub zog poob vim overcurrent.
Cia li coj ib qho piv txwv: 2400mA muab tshaj 5m, 20ga cable. Qhov ntawd yog 1.09V tso tawm. Koj tsis tuaj yeem them lub roj teeb Li-Ion los ntawm 3.91V cov khoom siv. Yog li koj lub charger Circuit Court yuav rov qab tawm thaum lub hwj chim ntws tawm. Ntawm 1000mA, 5m cable muab 4.55V. Nyob ntawm lub xov tooj lub zog tswj kev ua haujlwm, qhov no yuav txaus los muab qhov tsim nyog 4.3V them hluav taws xob rau Li-Ion roj teeb. Cov txheej txheem them nyiaj tsis tas yuav tsum tau 4.3V, tab sis nws yuav kawg. Yog li thaum koj xav tias koj muaj lub zog 2.4A "charger", qhov ntev cable ua kom koj yuav raug them ntev dua.
Yog tias koj siv 28ga cable, qhov them nqi hluav taws xob yuav poob qis dua 250mA! Qhov no yog qeeb dua li them los ntawm cov ntaub ntawv chaw nres nkoj hla ib qho luv luv cable.
Tshiab Fais Fab Kis Raws Cai
Oddly, smarter protocols zoo li QualComm's QuickCharge tsis tshua cuam tshuam los ntawm qhov no. Ntawm qhov tod tes, lawv nce qhov them nqi hluav taws xob thiab yog li tsis tshua muaj kev cuam tshuam los ntawm qhov induced voltage poob hauv cable. Thiab qee zaum lawv kos tsawg dua tam sim no, yog li muaj tsawg dua qhov kev poob hauv cable (lossis nyob ntawm qhov tam sim no, tsis yog voltage). QuickCharge 3.0 thiab USB Power Delivery kuj hloov kho lub zog thaum them nyiaj. Yog li ntawd, lawv tuaj yeem hloov kho rau cable poob hauv lub sijhawm tiag tiag, tsawg kawg rau qee qhov.
