Guhindura imbaraga imbaraga byanze bikunze. Intego nyamukuru yacu nukugabanya ibisohoka ripple kurwego rwihanganirwa. Igisubizo cyibanze kugirango ugere kuriyi ntego nukwirinda ibisekuruza. Mbere ya byose Nimpamvu.
Hamwe na switch ya SWITCH, ikigezweho muri inductance L nayo ihindagurika hejuru no hepfo ku gaciro keza k'ibisohoka. Kubwibyo, hazabaho kandi impagarike ninshuro imwe na Hindura kumusozo urangiye. Mubisanzwe, imvururu za rubavu zerekeza kuri ibi, bifitanye isano nubushobozi bwibisohoka capacitor na ESR. Inshuro yiyi mpanuka ni kimwe no guhinduranya amashanyarazi, hamwe nurwego rwa mirongo kugeza kuri magana kHz.
Mubyongeyeho, Hindura muri rusange ikoresha bipolar transistors cyangwa MOSFETs. Ntakibazo icyo aricyo cyose, hazabaho kuzamuka no kugabanya igihe iyo ifunguye kandi ipfuye. Muri iki gihe, nta rusaku ruzaba mu muzunguruko uhwanye nigihe cyo kwiyongera nkuko Switch izamuka igabanuka, cyangwa inshuro nke, kandi muri rusange ni MHz mirongo. Muri ubwo buryo, diode D iri muburyo bwo gukira. Umuzunguruko uhwanye nuruhererekane rwimikorere ya capacator hamwe na inductor, bizatera resonance, kandi urusaku rwurusaku ni MHz mirongo. Urwo rusaku rwombi rwitwa urusaku rwinshi-rwinshi, kandi amplitude ni nini cyane kuruta ripple.
Niba ari AC / DC ihindura, hiyongereyeho amajwi abiri yavuzwe haruguru (urusaku), hari urusaku rwa AC. Inshuro ninshuro yo kwinjiza amashanyarazi AC, hafi 50-60Hz. Hariho kandi urusaku rwa-modode, kubera ko igikoresho cyamashanyarazi cyinshi cyo guhinduranya amashanyarazi gikoresha igikonoshwa nka radiator, gitanga ubushobozi bungana.
Igipimo cyo guhinduranya imbaraga
Ibisabwa by'ibanze:
Gufatanya na oscilloscope AC
20MHz ntarengwa
Kuramo insinga y'ubutaka ya probe
1.Guhuza ni ugukuraho superposition DC voltage no kubona umurongo wukuri.
2. Gufungura umurongo wa 20MHz ntarengwa ni ukurinda kwivanga kw urusaku rwinshi-no gukumira ikosa. Kuberako amplitude yo murwego rwohejuru -ibintu byinshi ari binini, bigomba kuvaho iyo bipimwe.
3. Kuramo clip yubutaka bwa ocilloscope, hanyuma ukoreshe ibipimo byo gupima ubutaka kugirango ugabanye intambamyi. Amashami menshi ntabwo afite impeta zubutaka. Ariko suzuma iki kintu mugihe ureba niba cyujuje ibisabwa.
Indi ngingo ni ugukoresha 50Ω terminal. Ukurikije amakuru ya oscilloscope, 50Ω module nugukuraho ibice bya DC no gupima neza ibice bya AC. Ariko, hariho oscilloscopes nkeya hamwe nubushakashatsi bwihariye. Mu bihe byinshi, ikoreshwa rya probe kuva 100kΩ kugeza 10MΩ rikoreshwa, bikaba bidasobanutse byigihe gito.
Ibyavuzwe haruguru nibyo byibanze byibanze mugihe cyo gupima impinduka. Niba iperereza rya oscilloscope ridahuye neza n’ibisohoka, bigomba gupimwa n'imirongo igoramye cyangwa insinga za coaxial 50Ω.
Iyo upimye urusaku rwinshi-rwinshi, umurongo wuzuye wa oscilloscope muri rusange ni mega amagana kugeza kurwego rwa GHz. Abandi ni bamwe nkuko byavuzwe haruguru. Ahari ibigo bitandukanye bifite uburyo butandukanye bwo kugerageza. Mu isesengura ryanyuma, ugomba kumenya ibisubizo byawe.
Ibyerekeye oscilloscope:
Oscilloscope imwe ya digitale ntishobora gupima neza neza kubera kubangamira no kubika ubujyakuzimu. Muri iki gihe, oscilloscope igomba gusimburwa. Rimwe na rimwe nubwo umugozi wa oscilloscope ushaje wagutse ni mega mirongo gusa, imikorere iruta oscilloscope.
Kubuza guhinduranya imbaraga
Muguhindura imvururu, mubyukuri kandi mubyukuri birahari. Hariho uburyo butatu bwo guhagarika cyangwa kugabanya:
1. Ongera inductance hamwe nibisohoka capacitori yo kuyungurura
Ukurikije formulaire yo guhinduranya amashanyarazi, ingano ihindagurika hamwe nigiciro cyinduction ya inductive inductive ihinduka iringaniye, kandi ibisohoka bisohoka hamwe nubushobozi bwo gusohora buringaniye. Kubwibyo, kongera amashanyarazi nibisohoka birashobora kugabanya imvururu.
Ishusho iri hejuru nuburyo bugezweho muburyo bwo guhinduranya amashanyarazi L. Umuyoboro wacyo △ nshobora kubarwa uhereye kumata akurikira:
Birashobora kugaragara ko kongera L agaciro cyangwa kongera inshuro zo guhinduranya bishobora kugabanya ihindagurika ryubu muri inductance.
Mu buryo busa nabwo, isano iri hagati yisohoka n’ibisohoka: VRIPPLE = IMAX / (CO × F). Birashobora kugaragara ko kongera ubushobozi bwa capacitori agaciro bishobora kugabanya impagarara.
Uburyo busanzwe nugukoresha aluminium electrolytike capacator kugirango isohore ubushobozi kugirango igere ku ntego yubushobozi bunini. Nyamara, imiyoboro ya electrolytike ntabwo ikora neza muguhashya urusaku rwinshi-rwinshi, kandi ESR ni nini cyane, bityo izahuza capacitori ceramic iruhande rwayo kugirango ishobore kubura ubushobozi bwa aluminium electrolytike.
Mugihe kimwe, mugihe amashanyarazi akora, voltage VIN ya enterineti yinjira ntabwo ihinduka, ariko impinduka zubu hamwe na switch. Muri iki gihe, amashanyarazi yinjiza ntabwo atanga iriba ryubu, mubisanzwe hafi yinjiza yanyuma (gufata ubwoko bwamafaranga nkurugero, ni hafi ya Switch), kandi ihuza ubushobozi kugirango itange amashanyarazi.
Nyuma yo gukoresha iki cyemezo, Buck switch amashanyarazi yerekanwe kumashusho hepfo:
Uburyo bwavuzwe haruguru bugarukira gusa ku kugabanya imvururu. Kubera ingano ntarengwa, inductance ntabwo izaba nini cyane; ibisohoka bisohoka byiyongera kurwego runaka, kandi nta ngaruka zigaragara zo kugabanya imvururu; kwiyongera kwa guhinduranya inshuro bizongera igihombo. Iyo rero ibisabwa bikaze, ubu buryo ntabwo ari bwiza cyane.
Kubwamahame yo guhinduranya amashanyarazi, urashobora kwifashisha ubwoko butandukanye bwo guhinduranya amashanyarazi.
2. Ibice bibiri -yungurura ni ukongeramo mbere -urwego rwa LC muyunguruzi
Ingaruka zo kubuza LC muyungurura urusaku ruragaragara. Ukurikije imirongo ya ripple igomba gukurwaho, hitamo ubushobozi bwa inductor kugirango ukore akayunguruzo. Mubisanzwe, irashobora kugabanya imvururu neza. Muri iki kibazo, ugomba gusuzuma icyitegererezo cyibisubizo bya voltage. (Nkuko bigaragara hano)
Icyitegererezo cyatoranijwe mbere ya LC muyunguruzi (PA), nibisohoka voltage bizagabanuka. Kuberako inductance iyo ari yo yose ifite DC irwanya, mugihe hari ibisohoka ubu, hazabaho kugabanuka kwa voltage muri inductance, bikaviramo kugabanuka kumashanyarazi asohoka mumashanyarazi. Kandi iyi voltage igabanuka ihinduka nibisohoka.
Icyitegererezo cyatoranijwe nyuma ya LC muyunguruzi (PB), kugirango ibisohoka voltage ni voltage dushaka. Nyamara, inductance na capacitor byinjijwe imbere muri sisitemu yimbaraga, zishobora gutera sisitemu ihungabana.
3. Nyuma yumusaruro woguhindura amashanyarazi, huza LDO kuyungurura
Nuburyo bwiza cyane bwo kugabanya imvururu n urusaku. Ibisohoka bya voltage bihoraho kandi ntibikeneye guhindura sisitemu yambere yo gutanga ibitekerezo, ariko kandi nigiciro cyinshi -gukora neza kandi ikoresha ingufu nyinshi.
LDO iyariyo yose ifite icyerekezo: igipimo cyo guhagarika urusaku. Numurongo-DB umurongo, nkuko bigaragara ku gishushanyo gikurikira niwo murongo wa LT3024 LT3024.
Nyuma ya LDO, guhinduranya ibintu muri rusange biri munsi ya 10mV. Igishushanyo gikurikira nugereranya imvururu mbere na nyuma ya LDO:
Ugereranije nu murongo ujyanye nigishushanyo hejuru hamwe na flimform ibumoso, birashobora kugaragara ko ingaruka zo guhagarika LDO ari nziza cyane kubijyanye no guhinduranya amajana ya KHz. Ariko murwego rwo hejuru rwinshi, ingaruka za LDO ntabwo ari nziza.
Mugabanye imvururu. PCB insinga zo guhinduranya amashanyarazi nayo irakomeye. Ku rusaku rwinshi-rwinshi, kubera inshuro nini yumurongo mwinshi, nubwo nyuma -cyunguruzo nyuma yicyiciro gifite ingaruka runaka, ingaruka ntabwo zigaragara. Hariho ubushakashatsi bwihariye muriki kibazo. Uburyo bworoshye ni ukuba kuri diode hamwe na capacitance C cyangwa RC, cyangwa guhuza inductance murukurikirane.
Igishushanyo cyavuzwe haruguru ni umuzenguruko uhwanye na diode nyirizina. Iyo diode irihuta cyane, ibipimo bya parasitike bigomba gutekerezwa. Mugihe cyo gusubira inyuma kwa diode, inductance ihwanye na capacitance ihwanye na yo yabaye RC oscillator ya RC, itanga ihindagurika ryinshi -kenshi. Kugirango uhagarike uku guhindagurika kwinshi, birakenewe guhuza capacitance C cyangwa RC buffer umuyoboro kumpande zombi za diode. Kurwanya muri rusange ni 10Ω-100 ω, kandi ubushobozi ni 4.7PF-2.2NF.
Ubushobozi C cyangwa RC kuri diode C cyangwa RC birashobora kugenwa nibizamini bisubirwamo. Niba bidatoranijwe neza, bizatera ihungabana rikomeye.
Igihe cyo kohereza: Nyakanga-08-2023
