• about19

Dzidzisa iwe kuti udzidze zvakawanda nezve POE magetsi ekupa!

Shamwari zhinji dzakabvunza kakawanda kana poe simba rekupa rakagadzikana?Ndeipi tambo yakanakisa yemagetsi poe?Sei uchishandisa poe switch kuti usimbise kamera ichiri isina kuratidzwa?uye zvichingodaro, chokwadi, izvi zvine chekuita nekurasikirwa kwemagetsi kwePOE magetsi, izvo zviri nyore kufuratira muchirongwa.
1. Chii chinonzi POE magetsi
PoE inoreva kutumirwa kwedheta kune dzimwe IP-based terminals (zvakadai seP phones, wireless LAN access point APs, network cameras, etc.) pasina kuita chero shanduko kune iripo Ethernet Cat.5 cabling infrastructure.Panguva imwecheteyo, inogona zvakare kupa DC magetsi emagetsi tekinoroji yemidziyo yakadaro.
PoE tekinoroji inogona kuve nechokwadi chekushanda kwakajairika kwetiweki iripo uku uchivimbisa kuchengetedzwa kweiyo iripo yakarongeka cabling, uye kuderedza mutengo.
Iyo yakakwana yePoE system inosanganisira zvikamu zviviri: magetsi ekushandisa uye magetsi ekugamuchira michina.

Power Supply Equipment (PSE): Ethernet switch, marouters, hubs kana mamwe madhizaini ekuchinjisa anotsigira mabasa ePOE.
Powered mudziyo (PD): Mune yekutarisa system, inonyanya kuve network kamera (IPC).
2. POE simba rekupa chiyero
Iyo yazvino chiyero chepasi rose IEEE802.3bt ine zviviri zvinodiwa:
Rudzi rwekutanga: Chimwe chazvo ndechekuti simba rekubuda rePSE rinodiwa kuti risvike 60W, simba rinosvika pachigadziro chekugamuchira simba i51W (inogona kuonekwa kubva patafura yepamusoro kuti iyi ndiyo data yakaderera), uye iyo kurasikirwa kwesimba ndeye 9W.
Rudzi rwechipiri: PSE inodiwa kuti iwane simba rinobuda re90W, simba rinosvika pamudziyo wekugamuchira simba i71W, uye kurasikirwa kwemagetsi i19W.
Kubva pane zvataurwa pamusoro apa, zvinogona kuzivikanwa kuti nekuwedzera kwemagetsi, kurasikirwa kwemagetsi hakuna kuenzana nemagetsi, asi kurasikirwa kuri kuramba kuchikura, saka kurasikirwa kwePSE mukushanda kwekushanda kunogona kuverengwa sei?
3. POE kurasikirwa kwesimba
Saka ngatitarisei kuti kurasikirwa kwesimba rekondakita mujunior high school fizikisi kunoverengerwa sei.
Mutemo waJoule itsanangudzo yehuwandu hwekushandurwa kwesimba remagetsi kuita kupisa nekuita ikozvino.
Zviri mukati ndezvokuti: kupisa kunoitwa neazvino ichipfuura nemukonduri kunoenderana neskweya yezvino, kuenzana nekupokana kwemutyairi, uye zvinoenderana nenguva yainopihwa simba.Ndiko kuti, kushandiswa kwevashandi kunogadzirwa muhuwandu hwekuverenga.
Chirevo chesvomhu chemutemo waJoule: Q = I²Rt (inoshanda kune ese maseketi) uko Q isimba rakarasika, P, ini ndiri iyezvino, R ndiko kuramba, uye t ndiyo nguva.
Mukushandiswa chaiko, sezvo PSE nePD inoshanda panguva imwe chete, kurasikirwa hakuna chekuita nenguva.Mhedziso ndeyokuti kurasikirwa kwesimba kwetambo yetiweki muPOE system yakaenzana nekona yezvino uye yakaenzana nekukura kwekupikisa.Zvichitaurwa zviri nyore, kuti tideredze simba rekushandisa retiweki tambo, isu tinofanirwa kuedza kuita kuti ikozvino yewaya ive diki uye kushomeka kwetambo network kudiki.Pakati pavo, kukosha kwekudzikisa ikozvino kunonyanya kukosha.
Zvino ngatitarisei kune chaiwo maparameter eiyo standard standard:
Muchiyero cheIEEE802.3af, kushorwa kwetambo yetiweki ndeye 20Ω, inodiwa PSE inobuda voltage ndeye 44V, ikozvino 0.35A, uye kurasikirwa kwesimba P = 0.35 * 0.35 * 20 = 2.45W.
Saizvozvo, muIEEE802.3at chiyero, kushorwa kwetambo network ndeye 12.5Ω, iyo inodiwa voltage ndeye 50V, ikozvino ndeye 0.6A, uye kurasikirwa kwesimba P = 0.6 * 0.6 * 12.5 = 4.5W.
Zvose zviyero hazvina dambudziko kushandisa iyi nzira yekuverenga.Zvisinei, kana iyo IEEE802.3bt yasvika, haigone kuverengwa nenzira iyi.Kana iyo voltage iri 50V, simba re60W rinofanira kuda ikozvino ye1.2A.Panguva ino, kurasikirwa kwesimba P = 1.2 * 1.2 * 12.5 = 18W, kubvisa kurasikirwa kusvika kuPD Simba rechigadzirwa chacho chete 42W.
4. Zvikonzero zvePOE kurasikirwa kwesimba
Saka chikonzero chii?
Kuenzaniswa neinodiwa chaiyo ye51W, kune 9W shoma simba.Saka chii chaizvo chiri kukonzera kukanganisa kwekuverenga.

Ngatitarisei pakoramu yekupedzisira yeiyi data graph zvakare, uye nekunyatsocherechedza kuti ikozvino mune yekutanga IEEE802.3bt chiyero ichiri 0.6A, uye totarisa kune yakamonyoroka peya magetsi, tinogona kuona kuti peya ina dzeakamonyoroka peya simba. kugovera kunoshandiswa (IEEE802.3af, IEEE802. 3at inoshandiswa nemaviri maviri emakumbo akapoteredzwa) Nenzira iyi, nzira iyi inogona kuonekwa seyero yakafanana, ikozvino yedunhu rose ndeye 1.2A, asi kurasikirwa kwese kaviri. iyo yemapeya maviri eakamonyoroka peya magetsi,
Saka, kurasikirwa P = 0.6 * 0.6 * 12.5 * 2 = 9W.Kuenzaniswa ne2 pairs dzeakamonyoroka-pair cables, iyi nzira yekupa magetsi inochengetedza 9W yesimba, kuitira kuti PSE igone kuita kuti PD mudziyo ugamuchire simba kana simba rekubuda riri 60W chete.Simba rinogona kusvika pa51W.
Naizvozvo, kana isu tikasarudza PSE michina, isu tinofanirwa kutarisisa kudzikisa ikozvino uye kuwedzera voltage zvakanyanya sezvinobvira, zvikasadaro zvinozotungamira mukurasikirwa kwesimba rakawandisa.Simba rePSE midziyo chete inogona kushandiswa, asi haisi kuwanikwa mukuita.

Chishandiso chePD (senge kamera) chinoda 12V 12.95W kuti ishandiswe.Kana 12V2A PSE ikashandiswa, simba rekubuda ndiro 24W.
Mukushandiswa chaiko, kana yazvino iri 1A, kurasikirwa P = 1 * 1 * 20 = 20W.
Kana yazvino iri 2A, kurasikirwa P=2*2*20=80W,
Panguva ino, iyo yakakura ikozvino, yakakura kurasikirwa, uye yakawanda yesimba yakapedzwa.Zviripachena, mudziyo wePD haugone kugamuchira simba rinofambiswa nePSE, uye kamera ichave isina kukwana magetsi uye haigone kushanda zvakajairika.
Dambudziko iri rinowanikwawo mukuita.Muzviitiko zvakawanda, zvinoratidzika kuti simba rekushandisa rakakura zvakakwana kuti rishandiswe, asi kurasikirwa hakuverengwi.Nekuda kweizvozvo, kamera haigone kushanda zvakajairika nekuda kwekushaya simba kwemagetsi, uye chikonzero hachigone kuwanikwa nguva dzose.
5. POE simba rekupa kuramba
Ehe, izvo zvataurwa pamusoro apa ndiko kushorwa kwetambo yetiweki apo simba rekupa chinhambwe chiri 100 metres, inova simba rinowanikwa padanho rekupa magetsi, asi kana daro chairo rekupa magetsi riri diki, senge gumi chete. mamita, ipapo kupikisa kunongova 2Ω, zvakafanana Kurasikirwa kwemamita zana inongova 10% yekurasikirwa kwemamita zana, saka zvakakoshawo kunyatsofungisisa kushandiswa kwechokwadi pakusarudza PSE midziyo.
Kupokana kwemamita zana etiweki tambo dzemhando dzakasiyana dzemhando shanu dzemhando dzakamonyoroka:
1. Copper-clad simbi waya: 75-100Ω 2. Copper-akapfeka aruminiyamu waya: 24-28Ω 3. Mhangura-akapfeka sirivha waya: 15Ω
4. Copper-clad copper network cable: 42Ω 5. Oxygen-isina copper network cable: 9.5Ω
Zvinogona kuonekwa kuti zviri nani tambo, kushoma kushoma.Zvinoenderana neformula Q = I²Rt, ndiko kuti, simba rakarasika panguva yekupihwa kwemagetsi ndiro diki, saka ndosaka tambo ichifanira kushandiswa nemazvo.Chengetedzeka.
Sezvatataura pamusoro, iyo yekurasikirwa kwesimba fomula, Q=I²Rt, kuitira kuti poe magetsi ave nekurasikirwa kushoma kubva kuPSE magetsi ekupedzisira kune iyo PD yekugamuchira magetsi mudziyo, iyo shoma iripo uye kushoma kuramba kunodiwa kuti uwane. iyo yakanakisa mhedzisiro mune yese yekugovera magetsi maitiro.


Nguva yekutumira: Mar-17-2022