Beddelka Flyback: Khasn yar oo Tamar ah oo ku dhex jira Charger Taleefankaaga

Hordhac

Haddii aad waligaa dillaacday lebenka yar ee dallaca taleefankaaga, qaybta qallafsan ee gudaha ku jirta had iyo jeer waa transformer-ka duulista . Marka loo eego IEEE Technology Navigator, transformers flyback waa "magnetically-ku-xidhan tamarta-kaydinta inductors" kuwaas oo sameeya "qaybaha asaasiga ah ee sahayda korantada ee qaabka beddelka ah (SMPS) ee 5 ilaa 150 W" - taas oo ah sida saxda ah heerka awoodda ee xajiyeyaasha telefoonka, adapters laptop, iyo darawalada LED. Hal jumlad oo loogu talagalay bilawga: Transformer-ka duulista waa magnet yar oo marka hore nuugta tamarta korantada, ka dibna ku tufisa daqiiqad ka dib koronto ka duwan, iyada oo kaa ilaalinaysa inaad si badbaado leh uga go'do tamarta korontada.

Mabda'a iyo noocyada

Transformer-ka caadiga ah waa aalad "la sii maraayo": marka hadda uu galo qeybta hoose, hadda wuxuu ka baxaa heerka labaad isla markiiba, sida biyaha dhex qulqulaya tuubada. Transformer-ka duulista waa ka duwan yahay. Sida laga soo xigtay isla isha IEEE, transformer-ka duulista "wuxuu ku kaydiyaa tamarta xudunta magnetic inta lagu jiro mudada dhexda ah wuxuuna u sii daayaa tamartaas wareegga labaad kaliya ka dib marka furaha aasaasiga ahi furmo." Waa, farsamo ahaan, inductor-ka go'an ee isku xidhan ee xidhan magaca transformer-ka .

Laba qaab hawleed ayaa caadi ah (Wikipedia, Flyback Transformer ):

• Habka Continuous conduction (DCM) - xudunta ayaa si buuxda u faaruqisa tamarta wareeg kasta. Xakamaynta fudud, caan ku ah awoodda hoose.
• Habka socodsiinta joogtada ah (CCM) - tamarta qaar ayaa had iyo jeer ku sii jirta xudunta. Hadda ugu sarreeya ee hooseeya, doog yar, laakiin naqshad wareeg ah oo aad u dhib badan.

Halbeegyada muhiimka ah injineerku wuxuu dooranayaa:

• Inductance aasaasiga ah Lp (oo leh farqiga hawada dejinaya kaydinta tamarta) iyo beddelka inta jeer ee f _s (sida caadiga ah 20 kHz ilaa dhowr boqol oo kHz ee MnZn / NiZn ferrite cores) - oo ay weheliyaan wareegga shaqada D waxay dejiyeen awoodda la keenay.
• Isbeddelka saamiga n = Np / Ns - wuxuu dejiyaa tamarta wax soo saarka iyada oo loo marayo xiriirka duulimaadka caadiga ah: V _out = V _in · (N _s / N _p ) · D / (1 - D).
• Leakage inductance - cadowga; waxay keentaa koronto iyo EMI, sidaas darteed waxaa badanaa lagu dhejiyaa snubber RCD.

Tusaalaha codsiga: 20 W dabaylaha telefoonka

Mashiinnada dhexda waxaa lagu hagaajiyaa ilaa 400 V DC. MOSFET waxay beddeshaa heerka koowaad, dheh, 65 kHz. Marka MOSFET ay shid, hadda kor ayey u kacaysaa xagga hoose, tamartuna waxay ku dhistaa xudunta ferrite ee bannaan; diode-ka sare waa rogaal celis, sidaa darteed capacitor-ka wax soo saarka oo keliya ayaa quudiya taleefanka. Marka MOSFET ay damiso, goobta magnetic-ku waa dumaa, diode-ka labaad ayaa qabanaya, tamarta kaydsanna waxaa lagu daadiyaa capacitor-ka wax soo saarka ee 5 V (ama 9 V / 20 V si degdeg ah). Kormeeraha indhaha ayaa ku quudiya korantada wax-soo-saarka oo dib ugu celisa kontaroolaha PWM-da aasaasiga ah si loo habeeyo wareegga shaqada. Mid ka mid ah xudunta, dabaylaha go'doonsan ee badan ayaa keeni kara dhowr koronto hal mar - waana sababta ku dhawaad ​​qalab kasta oo tareennada badan leh ay isticmaalaan topology-gan.

Khalad guud iyo xaqiiqo xiiso leh

Fikradda khaldan ee ugu weyn ayaa ah in dib-u-soo-noqodku uu "u beddelo" tamarta habka beddelka caadiga ahi u sameeyo - dhab ahaantii, aasaasiga iyo sare waligood isku mar ma wada socdaan hadda . Dib-u-duuliddu waa qalab kaydin ah , ee maaha qalab la dhex maro . Nashqadeenayaasheedu waa inay ula dhaqmaan sida inductor-ka la isku daray oo leh meel bannaan, ama falanqayntu si xun bay u qaldan tahay.

Xaqiiqda xiisaha leh: isla wareeggaas ayaa la abuuray si loo wado xaaqidda tooska ah ee tuubada cathode-ray, halkaas oo loo yaqaan 'transformer' (LOPT) . Wikipedia wuxuu xusay in, telefishinnada CRT, heerka xariiqdu uu ahaa 15.625 kHz (PAL) ama 15.734 kHz (NTSC), iyo kormeerayaasha kombuyuutarku waxay ordeen 30-150 kHz - heer sare oo ku filan in magnetostriction ee xudunta uu isu beddelay qaylo sare oo la maqli karo. Isla marxaladda dib-u-soo-noqoshada ee maanta si aamusnaan ah u dallacaadda taleefankaaga mar ay soo saartay 15-30 kV xawaaraha korantada ee laydhka elektarooniga ah ee telefishan kasta oo CRT ah oo waligiis la iibiyay.