Abangane abaningi baye babuza kaningi ukuthi amandla ka-PoE azinzile yini? Iyiphi ikhebula elungele ukunikezwa kwamandla kwe-PoE? Kungani ikhamera ingabonisi uma inikwa amandla yiswishi ye-PoE? Futhi njalo, lezi empeleni zihlobene nokulahlekelwa kwamandla kagesi we-POE, okunganakwa kalula kumaphrojekthi.
1. Kuyini ukunikezwa kwamandla kwe-POE
I-PoE ibhekisela kubuchwepheshe bokuhlinzeka ngogesi we-DC kwamanye amatheminali asekelwe ku-IP (njengamafoni ase-IP, izindawo zokufinyelela zenethiwekhi yendawo engenazintambo, amakhamera enethiwekhi, njll.) ngaphandle kokulungiswa kwe-Ethernet Cat ekhona. 5 ingqalasizinda yekhebula.
Ubuchwepheshe be-PoE bungaqinisekisa ukuvikeleka kwekhebula ehleliwe ekhona kuyilapho kuqinisekisa ukusebenza okuvamile kwamanethiwekhi akhona, kuncishiswe izindleko.
Isistimu ye-PoE ephelele ihlanganisa izingxenye ezimbili: idivayisi yokuphela kokunikezwa kwamandla kanye nedivayisi yokugcina eyamukelayo.
Izisetshenziswa Zokuhlinzeka Ngamandla (PSE): Amaswishi e-Ethernet, amarutha, amahabhu, noma amanye amadivaysi okushintsha inethiwekhi asekela ukusebenza kwe-POE.
Idivayisi yokwamukela amandla (PD): Kusistimu yokuqapha, ikakhulukazi ikhamera yenethiwekhi (IPC).
2, POE amandla okunikezwa standard
Izinga lakamuva lamazwe ngamazwe IEEE802.3bt linezidingo ezimbili:
Uhlobo lokuqala: Enye yazo idinga i-PSE ukuze ifinyelele amandla okukhipha angu-60W, ngamandla afinyelela kudivayisi eyamukelayo engu-51W (njengoba kuboniswe kuthebula elingenhla, lena idatha ephansi kakhulu), kanye nokulahlekelwa kwamandla okungu-9W.
Indlela yesibili idinga ukuthi i-PSE ifinyelele amandla okukhipha angu-90W, ngamandla angu-71W afinyelela idivayisi eyamukelayo kanye nokulahlekelwa kwamandla angu-19W.
Kusukela kumazinga angenhla, kungabonakala ukuthi njengoba ukunikezwa kwamandla kwanda, ukulahlekelwa kwamandla akuhambisani nokunikezwa kwamandla, kodwa kunalokho kuyanda. Ngakho-ke ukulahlekelwa kwe-PSE kungabalwa kanjani ezinhlelweni zokusebenza?
3, POE amandla supply ukulahlekelwa
Ngakho-ke ake siqale sibheke ukuthi i-middle school physics ibala kanjani ukulahleka kwamandla ocingo.
Umthetho kaJoule umthetho ochaza ngokwezibalo ukuguqulwa kwamandla kagesi abe amandla ashisayo ngokuqhuba isimanje.
Okuqukethwe yilokhu: Ukushisa okukhiqizwa i-current edlula ku-conductor kuhambisana namandla we-quadratic wamanje, ukumelana kwe-conductor, nesikhathi sokufakwa kukagesi. Okusho ukuthi, ukusetshenziswa kwabasebenzi okukhiqizwa phakathi nenqubo yokubala.
Inkulumo yezibalo ye-Joule yomthetho: Q=I ² Rt (isebenza kuwo wonke amasekhethi), lapho u-Q ewukuphelelwa amandla P, mina ngingowamanje, u-R ukumelana, kanye no-t isikhathi.
Ekusetshenzisweni okungokoqobo, njengoba i-PSE ne-PD isebenza kanyekanye, ukulahlekelwa kuzimele esikhathini. Isiphetho siwukuthi ohlelweni lwe-POE, amandla okulahlekelwa kwekhebula lenethiwekhi alingana ngokuqondile namandla we-quadratic wamanje futhi alingana ngokuqondile nobukhulu bokumelana. Kalula nje, ukuze kuncishiswe ukusetshenziswa kwamandla kwentambo yenethiwekhi, kufanele sizame ukunciphisa okwamanje kocingo kanye nokumelana kwekhebula lenethiwekhi ngangokunokwenzeka. Ukubaluleka kokunciphisa umsinga kubaluleke kakhulu.
Ngakho-ke ake sibheke imingcele ethile yamazinga omhlaba:
Esilinganisweni se-IEEE802.3af, ukumelana kwentambo yenethiwekhi ngu-20 Ω, i-voltage edingekayo ye-PSE ephumayo ingu-44V, yamanje ngu-0.35A, namandla okulahlekelwa P=0.35 * 0.35 * 20=2.45W.
Ngokufanayo, ku-IEEE802.3at evamile, ukumelana kwekhebula lenethiwekhi ngu-12.5 Ω, i-voltage edingekayo yi-50V, yamanje ngu-0.6A, kanye namandla okulahlekelwa P=0.6 * 0.6 * 12.5 = 4.5W.
Ayikho inkinga ngokusebenzisa le ndlela yokubala kuwo womabili amazinga. Kodwa uma kuziwa ezingeni le-IEEE802.3bt, alikwazi ukubalwa kanje. Uma i-voltage ingu-50V futhi amandla okufinyelela ku-60W adinga ukuba ngu-1.2A wamanje, khona-ke amandla okulahlekelwa ngu-P=1.2 * 1.2 * 12.5=18W. Ukukhipha ukulahlekelwa, amandla okufinyelela idivayisi ye-PD angama-42W kuphela.
4. Izizathu zokulahlekelwa amandla ku-POE
Ngakho siyini ngempela isizathu?
Isidingo sangempela sama-51W sincishiswa ngo-9W wamandla kagesi. Ngakho yini ngempela ebangele iphutha lokubala.
Izisetshenziswa Zokuhlinzeka Ngamandla (PSE): Amaswishi e-Ethernet, amarutha, amahabhu, noma amanye amadivaysi okushintsha inethiwekhi asekela ukusebenza kwe-POE.
Idivayisi yokwamukela amandla (PD): Kusistimu yokuqapha, ikakhulukazi ikhamera yenethiwekhi (IPC).
2, POE amandla okunikezwa standard
Izinga lakamuva lamazwe ngamazwe IEEE802.3bt linezidingo ezimbili:
Uhlobo lokuqala: Enye yazo idinga i-PSE ukuze ifinyelele amandla okukhipha angu-60W, ngamandla afinyelela kudivayisi eyamukelayo engu-51W (njengoba kuboniswe kuthebula elingenhla, lena idatha ephansi kakhulu), kanye nokulahlekelwa kwamandla okungu-9W.
Indlela yesibili idinga ukuthi i-PSE ifinyelele amandla okukhipha angu-90W, ngamandla angu-71W afinyelela idivayisi eyamukelayo kanye nokulahlekelwa kwamandla angu-19W.
Kusukela kumazinga angenhla, kungabonakala ukuthi njengoba ukunikezwa kwamandla kwanda, ukulahlekelwa kwamandla akuhambisani nokunikezwa kwamandla, kodwa kunalokho kuyanda. Ngakho-ke ukulahlekelwa kwe-PSE kungabalwa kanjani ezinhlelweni zokusebenza?
3, POE amandla supply ukulahlekelwa
Ngakho-ke ake siqale sibheke ukuthi i-middle school physics ibala kanjani ukulahleka kwamandla ocingo.
Umthetho kaJoule umthetho ochaza ngokwezibalo ukuguqulwa kwamandla kagesi abe amandla ashisayo ngokuqhuba isimanje.
Okuqukethwe yilokhu: Ukushisa okukhiqizwa i-current edlula ku-conductor kuhambisana namandla we-quadratic wamanje, ukumelana kwe-conductor, nesikhathi sokufakwa kukagesi. Okusho ukuthi, ukusetshenziswa kwabasebenzi okukhiqizwa phakathi nenqubo yokubala.
Inkulumo yezibalo ye-Joule yomthetho: Q=I ² Rt (isebenza kuwo wonke amasekhethi), lapho u-Q ewukuphelelwa amandla P, mina ngingowamanje, u-R ukumelana, kanye no-t isikhathi.
Ekusetshenzisweni okungokoqobo, njengoba i-PSE ne-PD isebenza kanyekanye, ukulahlekelwa kuzimele esikhathini. Isiphetho siwukuthi ohlelweni lwe-POE, amandla okulahlekelwa kwekhebula lenethiwekhi alingana ngokuqondile namandla we-quadratic wamanje futhi alingana ngokuqondile nobukhulu bokumelana. Kalula nje, ukuze kuncishiswe ukusetshenziswa kwamandla kwentambo yenethiwekhi, kufanele sizame ukunciphisa okwamanje kocingo kanye nokumelana kwekhebula lenethiwekhi ngangokunokwenzeka. Ukubaluleka kokunciphisa umsinga kubaluleke kakhulu.
Ngakho-ke ake sibheke imingcele ethile yamazinga omhlaba:
Esilinganisweni se-IEEE802.3af, ukumelana kwentambo yenethiwekhi ngu-20 Ω, i-voltage edingekayo ye-PSE ephumayo ingu-44V, yamanje ngu-0.35A, namandla okulahlekelwa P=0.35 * 0.35 * 20=2.45W.
Ngokufanayo, ku-IEEE802.3at evamile, ukumelana kwekhebula lenethiwekhi ngu-12.5 Ω, i-voltage edingekayo yi-50V, yamanje ngu-0.6A, kanye namandla okulahlekelwa P=0.6 * 0.6 * 12.5 = 4.5W.
Ayikho inkinga ngokusebenzisa le ndlela yokubala kuwo womabili amazinga. Kodwa uma kuziwa ezingeni le-IEEE802.3bt, alikwazi ukubalwa kanje. Uma i-voltage ingu-50V futhi amandla okufinyelela ku-60W adinga ukuba ngu-1.2A wamanje, khona-ke amandla okulahlekelwa ngu-P=1.2 * 1.2 * 12.5=18W. Ukukhipha ukulahlekelwa, amandla okufinyelela idivayisi ye-PD angama-42W kuphela.
4. Izizathu zokulahlekelwa amandla ku-POE
Ngakho siyini ngempela isizathu?
Isidingo sangempela sama-51W sincishiswa ngo-9W wamandla kagesi. Ngakho yini ngempela ebangele iphutha lokubala.
Kuyabonakala ukuthi uma ikhebula lingcono, ukumelana okuncane kakhulu, ngokuya ngefomula ethi Q=I ² Rt, okusho ukuthi ukulahleka kwamandla ngesikhathi senqubo yokunikezwa kwamandla kukuncane, ngakho-ke yingakho kudingekile ukusebenzisa izintambo. kahle. Kunconywa ukusebenzisa izintambo zeSigaba 6 njengendlela ephephile.
Njengoba sishilo ngenhla, ifomula yamandla okulahlekelwa, Q=I ² Rt, ukuze kwehliswe ukulahlekelwa phakathi kwetheminali yokuphakela amandla kagesi ye-PSE kanye nezisetshenziswa zokwamukela i-PD, ubuncane bamanje nokumelana kuyadingeka ukuze kuzuzwe ukusebenza okungcono kakhulu kuwo wonke amandla. inqubo yokuhlinzeka.
Landela i-CF FIBERLINK ukuze ufunde kabanzi mayelana nolwazi lwezokuphepha !!! I-Hotline Yesevisi Yomhlaba Wonke: 86752-2586485
Isikhathi sokuthumela: May-30-2023