Qhia koj 6 lub zog tsim kev txawj ntse
01 Ferrite Sib Nqus Amplifier hauv Flyback Power Supply
Rau ib tug dual tso zis flyback mov nrog lub hwj chim tiag tiag ntawm ob qho tib si outputs (5V 2A thiab 12V 3A, ob qho tib si tswj los ntawm ± 5 feem pua), thaum lub voltage ncav cuag 12V nws mus rau hauv ib tug xoom load xeev thiab kho tsis tau nyob rau hauv lub 5 feem pua. Lub linear regulator yog ib qho kev daws teeb meem, tab sis tseem tsis zoo vim nws cov nqi siab thiab kev ua haujlwm tsis zoo.
Peb qhov kev daws teeb meem yog siv lub tshuab hluav taws xob sib nqus ntawm 12V cov zis, txawm tias flyback topology tuaj yeem siv tau. Txhawm rau txo tus nqi, nws raug nquahu kom siv ferrite magnetic amplifier. Txawm li cas los xij, kev tswj xyuas Circuit Court ntawm ferrite magnetic amplifier yog qhov txawv ntawm cov khoom siv sib nqus hysteresis voj voog (cov khoom siv magnetic permeability siab). Lub ferrite tswj Circuit Court (D1 thiab Q1) dab dej tam sim no kom tswj tau lub zog ntawm cov zis. Qhov no Circuit Court tau raug kuaj kom meej. Lub transformer windings yog tsim rau 5V thiab 13V tso zis. Lub Circuit Court tuaj yeem ua tiav sub-1W input zog (5V 300mW thiab 12V xoom load) thaum ua tiav ± 5 feem pua txoj cai ntawm 12V cov zis.
02 Siv arc crowbar circuit uas twb muaj lawm los muab kev tiv thaiv overcurrent
Xav txog 5V 2A thiab 12V 3A flyback khoom siv. Ib qho ntawm cov ntsiab lus tseem ceeb ntawm cov khoom siv hluav taws xob no yog kev tiv thaiv overpower (OPP) ntawm 5V tso zis thaum 12V tso zis mus txog tsis muaj load lossis lub teeb heev. Ob qhov kev tso tawm nthuav tawm ± 5 feem pua ntawm cov kev cai voltage.
Rau cov kev daws teeb meem zoo sib xws, kev siv cov kev xav resistors degrades cross-regulation kev ua tau zoo, thiab fuses yog kim. Txawm li cas los xij, crowbar circuits rau kev tiv thaiv overvoltage (OVP) yog tam sim no muaj. Qhov Circuit Court no muaj peev xwm ua tau raws li OPP thiab cov kev cai voltage, uas tuaj yeem ua tiav los ntawm kev siv ib nrab arc crowbar circuit.
R1 thiab VR1 tsim ib qho active preload ntawm 12V tso zis, uas tso cai rau 12V kev cai thaum lub 12V tso zis yog maj mam loaded. Thaum 5V tso zis yog nyob rau hauv ib qho overload, qhov voltage ntawm 5V tso zis yuav poob. Dummy loads kos ntau tam sim no. Ib qho hluav taws xob poob hla R1 tuaj yeem siv los ntsuas qhov tam sim no loj. Q1 tig rau thiab ua rau OPP Circuit Court.
03 Active shunt regulator thiab preload
Flyback yog tam sim no nrov tshaj plaws topology nyob rau hauv lub tshav pob ntawm kev hloov fais fab mov khoom los ntawm kab voltage AC mus rau tsawg voltage DC. Ib qho laj thawj tseem ceeb rau qhov no yog qhov tshwj xeeb tus nqi-kev ua tau zoo ntawm kev muab ntau qhov tso zis voltages los ntawm tsuas yog ntxiv cov windings ntxiv rau qhov hloov pauv theem nrab.
Feem ntau, cov lus tawm tswv yim los ntawm cov zis nrog cov kev cai nruj tshaj plaws rau kev ua siab ntev. Qhov tso zis no ces txhais cov lem ib volt rau tag nrho lwm yam thib ob windings. Vim qhov cuam tshuam inductance, cov zis tawm tsis tuaj yeem ua tiav qhov kev xav tau ntawm cov zis hluav taws xob hla kev tswj hwm, tshwj xeeb tshaj yog tias cov khoom tso tawm tuaj yeem raug tshem tawm lossis hnyav heev vim tias lwm cov khoom siv tau tag nrho.
Ib qho kev tswj hwm tom qab lossis dummy load tuaj yeem siv los tiv thaiv qhov hluav taws xob ntawm qhov tso zis los ntawm kev nce hauv cov xwm txheej zoo li no. Txawm li cas los xij, vim tias tus nqi nce ntxiv thiab txo qhov ua tau zoo ntawm cov neeg tswj hwm tom qab lossis cov khoom siv dummy, lawv tsis tau txaus nyiam, tshwj xeeb tshaj yog nyob rau xyoo tas los no rau tsis muaj kev thauj khoom thiab / lossis kev siv hluav taws xob standby hauv ntau cov neeg siv khoom siv. Nyob rau hauv cov xwm txheej ntawm cov kev cai nruj zuj zus, qhov kev tsim no tau pib tsis quav ntsej. Lub active shunt regulator qhia nyob rau hauv daim duab 3 tsis tsuas yog daws qhov teeb meem voltage tswj, tab sis kuj txo tus nqi thiab efficiency cuam tshuam.
Lub voj voog ua haujlwm raws li hauv qab no: Thaum ob qho kev tso tawm nyob rau hauv kev cai, resistor divider R14 thiab R13 bias transistor Q5, uas ua rau Q4 thiab Q1 tawm. Raws li cov kev ua haujlwm no, tam sim no los ntawm Q5 ua raws li qhov me me ua ntej ntawm 5V tso zis.
Tus qauv sib txawv ntawm 5V tso zis thiab 3.3V tso zis yog 1.7V. Thaum lub load yuav tsum tau ntxiv tam sim no los ntawm 3.3V tso zis yam tsis muaj qhov sib npaug ntawm load tam sim no los ntawm 5V tso zis, cov zis voltage yuav nce piv rau 3.3V tso zis. Nrog rau qhov sib txawv ntawm qhov sib txawv ntawm ntau tshaj li ntawm 100 mV, Q5 yuav raug txiav tawm, tig rau Q4 thiab Q1 thiab tso cai rau tam sim no ntws los ntawm 5V cov zis mus rau 3.3V cov zis. Qhov tam sim no yuav poob qhov voltage ntawm 5V tso zis, txo qhov voltage qhov sib txawv ntawm ob qhov zis.
Tus nqi tam sim no hauv Q1 yog txiav txim siab los ntawm qhov sib txawv ntawm qhov voltage ntawm ob qhov zis. Yog li ntawd, lub Circuit Court tuaj yeem khaws ob qhov kev tawm tswv yim tsis hais txog ntawm lawv qhov chaw thau khoom, txawm tias qhov xwm txheej phem tshaj plaws uas cov zis 3.3V tau ntim tag nrho thiab 5V tso zis tawm. Q5 thiab Q4 hauv kev tsim muab qhov kub thiab txias vim tias VBE qhov kub thiab txias hloov hauv txhua lub transistor tshem tawm ib leeg. Diodes D8 thiab D9 tsis tas yuav tsum tau tab sis tuaj yeem siv los txo cov hluav taws xob dissipation hauv Q1, tshem tawm qhov xav tau ntxiv lub dab dej kub rau qhov tsim.
Lub Circuit Court tsuas yog teb rau qhov sib txawv ntawm qhov sib txawv ntawm ob qhov hluav taws xob thiab feem ntau tsis ua haujlwm ntawm tag nrho thiab lub teeb load. Txij li thaum lub shunt regulator txuas los ntawm 5V tso zis mus rau 3.3V tso zis, lub Circuit Court yuav txo tau active dissipation los ntawm 66 feem pua piv rau ib tug grounded shunt regulator. Qhov tshwm sim yog high efficiency ntawm tag nrho cov load thiab tsawg zog noj los ntawm lub teeb load mus rau tsis muaj load.
04 High Voltage Input Switching Power Supply siv StackFET
Cov khoom lag luam uas ua haujlwm ntawm peb-theem AC feem ntau yuav tsum muaj lub zog pab cuam uas tuaj yeem muab kev tswj hwm qis-voltage DC rau analog thiab digital circuits. Piv txwv ntawm cov ntawv thov muaj xws li kev lag luam drives, UPS systems thiab lub zog ntsuas.
Cov lus qhia tshwj xeeb rau hom khoom siv hluav taws xob no yog nruj dua li qhov xav tau rau cov txheej txheem tawm ntawm lub txee. Tsis tsuas yog cov input voltages siab dua hauv cov ntawv thov no, tab sis cov cuab yeej tsim los rau peb-theem daim ntawv thov nyob rau hauv ib puag ncig kev lag luam yuav tsum zam qhov kev hloov pauv loj heev - suav nrog lub sij hawm ncua sij hawm, lub zog hluav taws xob, thiab qee zaus poob ntawm ib lossis ntau theem. Tsis tas li ntawd, qhov ntsuas qhov hluav taws xob tau teev tseg rau cov khoom siv pabcuam no tuaj yeem dav li 57 VAC txog 580 VAC.
Tsim kom muaj ntau yam kev hloov pauv hluav taws xob tuaj yeem ua rau muaj kev sib tw, feem ntau yog vim tus nqi siab ntawm high-voltage MOSFETs thiab kev txwv ntawm ntau yam ntawm cov tsoos PWM tswj loops. StackFET thev naus laus zis tso cai rau kev sib xyaw ua ke ntawm pheej yig 600V ntsuas qis voltage MOSFETs thiab cov khoom siv hluav taws xob sib xyaw ua ke los ntawm Kev Sib Txuas Hluav Taws Xob, tso cai yooj yim thiab pheej yig tsim los ntawm kev hloov cov khoom siv hluav taws xob muaj peev xwm ua haujlwm dhau ntawm qhov kev tawm tswv yim dav dav.
Lub voj voog ua haujlwm raws li hauv qab no: Cov tam sim no ntawm cov khoom siv hluav taws xob tuaj yeem los ntawm peb-theem peb-xaim lossis plaub-xaim, lossis txawm tias los ntawm ib-theem system. Peb-theem rectifier muaj diodes D1-D8. Resistor R1-R4 muab kev txwv tam sim no. Yog tias siv cov resistors fusible, cov resistors tuaj yeem raug cuam tshuam tsis zoo thaum lub sijhawm ua txhaum yam tsis tas yuav tsum muaj lub fuse cais. Lub pi lim muaj C5, C6, C7, C8, thiab L1 los lim cov DC voltage rectified.
Resistor R13 thiab R15 yog siv los sib npaug qhov voltage ntawm cov input lim capacitor. Thaum lub MOSFET nyob rau hauv lub integrated hloov (U1) tig rau, lub hauv paus ntawm Q1 yuav raug rub qis, R6, R7, thiab R8 yuav muab lub rooj vag tam sim no, thiab lub junction capacitance ntawm VR1 mus rau VR3 yuav tig rau Q1. Zener diode VR4 yog siv los txwv lub rooj vag qhov hluav taws xob siv rau Q1. Thaum MOSFET hauv U1 tawm, qhov siab tshaj plaws ntws tawm ntawm U1 yog clamped los ntawm 450 V clamping network uas muaj VR1, VR2 thiab VR3. Qhov no txwv cov dej ntws tawm ntawm U1 txog kwv yees li 450 V.
Ib qho ntxiv voltage ntawm qhov kawg ntawm winding txuas nrog Q1 yuav raug siv rau Q1. Qhov kev tsim no zoo faib tag nrho cov kev hloov kho cov tswv yim DC voltage thiab flyback voltage ntawm Q1 thiab U1. Resistor R9 yog siv los txwv cov zaus oscillations thaum lub sij hawm hloov, thiab clamp network VR5, D9 thiab R10 yog siv los txwv lub ncov voltage ntawm lub hauv paus vim to to inductance thaum lub sij hawm flyback.
Output rectification yog muab los ntawm D1. C2 yog qhov tso zis lim. L2 thiab C3 tsim cov lim thib ob los txo cov kev hloov pauv ntawm cov zis.
VR6 tig rau thaum qhov tso zis hluav taws xob tshaj qhov tag nrho qhov hluav taws xob poob hla lub optocoupler diode thiab VR6. Kev hloov pauv ntawm cov zis hluav taws xob ua rau muaj kev hloov pauv tam sim no los ntawm optocoupler diode hauv U2, uas hloov pauv tam sim no ntws los ntawm transistor hauv U2B. Thaum qhov tam sim no tshaj FB tus pin pib tam sim no ntawm U1, lub voj voog tom ntej yog inhibited. Cov kev cai tso zis tuaj yeem ua tiav los ntawm kev tswj cov naj npawb ntawm kev pab thiab lov tes taw mus. Thaum lub voj voog hloov pauv tau qhib, lub voj voog xaus thaum qhov tam sim no nce mus rau U1 qhov kev txwv sab hauv tam sim no. R11 yog siv los txwv qhov tam sim no los ntawm optocoupler thaum lub sijhawm thauj khoom thiab kho qhov nce ntawm cov lus tawm tswv yim. Resistor R12 yog siv los cuam tshuam Zener diode VR6.
IC U1 (LNK 304) muaj kev ua haujlwm ua haujlwm kom lub voj voog tiv thaiv kev poob ntawm cov lus taw qhia, luv luv ntawm qhov tso zis thiab dhau. Txij li thaum U1 tau siv ncaj qha los ntawm nws tus pin DRAIN, tsis tas yuav muaj kev cuam tshuam ntxiv winding ntawm lub transformer. C4 yog siv los muab cov khoom siv sab hauv decoupling.
05 Kev xaiv zoo ntawm rectifier diodes tuaj yeem ua kom yooj yim thiab txo tus nqi ntawm EMI lim circuits hauv AC / DC converters
Qhov Circuit Court no tuaj yeem ua kom yooj yim thiab txo tus nqi ntawm EMI lim circuits hauv AC / DC converters. Ua kom muaj AC / DC fais fab mov EMI raws li yuav tsum tau siv ntau ntawm EMI lim cov khoom xws li X thiab Y capacitors. Standard input circuits rau AC/DC fais fab mov muaj xws li ib tug choj rectifier los kho qhov input voltage (feem ntau yog 50-60 Hz). Txij li qhov no yog qhov tsawg zaus AC input voltage, tus qauv diodes xws li 1N400X series ntawm diodes tuaj yeem siv tau, thiab vim tias cov no yog qhov tsawg tshaj plaws.
Cov khoom siv lim dej no yog siv los txo EMI tsim los ntawm cov khoom siv hluav taws xob kom ua raws li cov kev txwv luam tawm EMI. Txawm li cas los xij, txij li kev ntsuas siv los sau EMI tsuas yog pib ntawm 150 kHz, thiab AC kab hluav taws xob zaus tsuas yog 50 lossis 60 Hz, lub sijhawm rov qab los ntawm tus qauv diodes (saib daim duab 5-1) siv hauv choj rectifiers yog kuj qeeb. ntev thiab feem ntau tsis ncaj qha ntsig txog EMI tiam.
Txawm li cas los xij, lub zog lim kev ua haujlwm yav dhau los qee zaum suav nrog cov hluav taws xob hluav taws xob ua rau muaj kev siv hluav taws xob nrawm los ntawm kev siv hluav taws xob ua rau los ntawm kev siv hluav taws xob kom los ntawm kev siv hluav taws xob kom los ntawm kev siv hluav taws xob ntau los ua los ntawm kev kho hluav taws xob kom los ntawm kev siv hluav taws xob kom los ntawm kev siv hluav taws xob hauv cov khoom siv tsawg zaus voltage.
Cov capacitors no tsis xav tau yog tias cov diodes rov qab tau siv rau hauv tus choj rectifier. Thaum qhov hluav taws xob hla cov diodes pib thim rov qab, lawv rov qab sai heev (saib daim duab 5-2). Qhov no yuav txo tau txoj kab stray inductive excitation nyob rau hauv AC input kab los ntawm kev txo cov zaus zaus tig tawm snaps thiab EMI. Txij li thaum 2 diodes tuaj yeem ua txhua lub voj voog ib nrab, tsuas yog 2 ntawm 4 diodes yuav tsum yog hom rov qab sai. Ib yam li ntawd, tsuas yog ib qho ntawm ob lub diodes ua txhua lub voj voog ib nrab yuav tsum muaj tus cwj pwm rov qab sai.
Cov input voltage thiab tam sim no waveforms qhia lub diode snap thaum kawg ntawm kev rov qab los.
06 Siv Soft-Start los lov tes taw cov nqi qis kom muaj cov kab hluav taws xob tam sim no
Txhawm rau kom ua tau raws li cov lus qhia tshwj xeeb ntawm lub zog standby, qee cov khoom siv hluav taws xob ntau ntau yog tsim los txiav tawm cov zis thaum lub teeb liab standby nquag.
Feem ntau, qhov no yog ua tiav los ntawm kev xa tawm series bypass bipolar transistor (BJT) lossis MOSFET. Rau cov zis tam sim no qis, BJTs tuaj yeem yog qhov tsim nyog thiab tus nqi qis dua rau MOSFETs yog tias lub zog hloov hluav taws xob tau tsim nrog cov hluav taws xob txuas ntxiv hla cov transistors hauv siab.
