Kev tshuaj xyuas ntau txoj hauv kev rau Singlechip Controlled Switching Power Supply
Muaj ntau txoj hauv kev los tswj cov hluav taws xob tso tawm ntawm ib qho-chip microcomputer tswj kev hloov hluav taws xob.
Ib qho yog tias lub microcontroller tso tawm qhov hluav taws xob (ntawm DA nti lossis PWM hom), uas yog siv los ua qhov siv hluav taws xob rau cov khoom siv hluav taws xob. Txoj kev no tsuas yog hloov qhov qub siv hluav taws xob nrog lub microcontroller, uas tuaj yeem nkag mus rau qhov tso zis hluav taws xob tus nqi ntawm lub zog hluav taws xob nrog lub pob. Lub microcontroller tsis ntxiv cov lus tawm tswv yim ntawm lub zog hluav taws xob, thiab tsis muaj kev hloov pauv rau lub zog hluav taws xob. Txoj kev no yog qhov yooj yim tshaj plaws.
Qhov thib ob yog kom nthuav dav AD ntawm lub microcontroller, txuas ntxiv tshawb xyuas qhov tso zis hluav taws xob ntawm lub zog hluav taws xob, kho qhov tso zis ntawm DA raws li qhov sib txawv ntawm cov zis hluav taws xob ntawm lub zog hluav taws xob thiab cov nqi teeb tsa, tswj PWM nti, thiab indirectly tswj kev khiav hauj lwm ntawm lub hwj chim mov. Nyob rau hauv txoj kev no, lub microcontroller tau ntxiv rau cov lus tawm tswv yim ntawm lub hwj huam mov, hloov qhov txuas txuas txuas ntxiv. Qhov kev pabcuam microcontroller yuav tsum siv PID algorithm nyuaj dua.
Qhov thib peb yog kom nthuav dav AD ntawm lub microcontroller, txuas ntxiv tshawb xyuas qhov tso zis hluav taws xob ntawm lub zog hluav taws xob, thiab tso tawm PWM nthwv dej raws li qhov sib txawv ntawm cov zis hluav taws xob ntawm lub zog hluav taws xob thiab cov nqi teeb tsa, ncaj qha tswj kev ua haujlwm ntawm lub zog hluav taws xob. . Li no, microcontroller feem ntau koom nrog hauv kev ua haujlwm ntawm lub zog.
Qhov thib peb txoj kev yog qhov zoo tshaj plaws ib leeg-chip microcomputer tswj hloov fais fab mov, tab sis qhov yuav tsum tau rau ib-chip microcontrollers kuj yog siab tshaj. Lub microcontroller yuav tsum muaj kev suav ceev ceev thiab tuaj yeem tso tawm PWM tsis muaj zog txaus. Xws li microcontrollers yog obviously kim.
Qhov ceev ntawm DSP raws li microcontrollers siab txaus, tab sis tus nqi tam sim no kuj siab heev. Los ntawm tus nqi saib xyuas, qhov feem pua ntawm cov nqi hluav taws xob loj dhau los yuav tau txais.
Ntawm cov nqi qis microcontrollers, AVR series yog qhov ceev tshaj plaws thiab muaj PWM tso zis, uas tuaj yeem txiav txim siab rau kev saws me nyuam. Txawm li cas los xij, kev ua haujlwm zaus ntawm AVR microcontroller tseem tsis siab txaus thiab tsuas yog siv tau tsis txaus siab. Hauv qab no, peb yuav suav cov qib uas AVR microcontroller tuaj yeem tswj tau ncaj qha kev ua haujlwm ntawm kev hloov hluav taws xob.
Hauv AVR microcontroller, qhov siab tshaj plaws moos zaus yog 16MHz. Yog tias qhov kev daws teeb meem PWM yog 10 ntsis, ces qhov zaus ntawm PWM nthwv dej, tseem hu ua kev khiav hauj lwm zaus ntawm kev hloov hluav taws xob, yog 16000000 / 1024=15625 (Hz). Nws yog qhov tseeb tsis txaus rau qhov hloov hluav taws xob hloov mus ua haujlwm ntawm qhov zaus no (hauv lub suab ntau). Yog li, noj PWM daws teeb meem raws li 9 khoom, qhov ua haujlwm zaus ntawm lub zog hloov pauv lub sijhawm no yog 16000000 / 512=32768 (Hz), uas tuaj yeem siv sab nraum lub suab ntau, tab sis tseem muaj qee qhov kev ncua deb ntawm lub ua hauj lwm zaus ntawm niaj hnub hloov hluav taws xob khoom siv.
Txawm li cas los xij, nws yuav tsum raug sau tseg tias {{0}} kev daws teeb meem me ntsis txhais tau tias thaum lub sij hawm lub hwj chim transistor ntawm lub voj voog tawm, nws tuaj yeem muab faib ua 512 ntu. Nyob rau hauv cov nqe lus ntawm conduction ib leeg, piv txwv li ib lub luag hauj lwm voj voog ntawm 0.5, nws tsuas yog muab faib ua 256 qhov chaw. Xav tias qhov dav ntawm mem tes tsis yog linearly cuam tshuam nrog cov khoom siv hluav taws xob, nws yuav tsum ua kom tsawg kawg ib zaug ntxiv. Nyob rau hauv lwm yam lus, lub hwj chim tso zis tsuas yog tswj tau mus rau 1/128 nyob rau hauv feem ntau, tsis hais txog ntawm load hloov los yog daim phiaj voltage hloov, lub degree ntawm kev tswj tsuas yog mus txog qhov no.
