30V / 3A tsis tu ncua voltage / tas li tam sim no DC adjustable tswj fais fab mov
Cov yam ntxwv ntawm Circuit
(1) Digital voltmeter voltage thiab tam sim no tso saib hauv daim duab saum toj no, tso saib qhov tseeb 0.1 V 0.01A hauv daim duab saum toj no
(2) Kev tiv thaiv tam sim no muaj nuj nqi, txwv tam sim no los ntawm ammeter. Ntawd yog, nws muaj qhov ua haujlwm tsis tu ncua tam sim no. Qhov kev ua haujlwm no tuaj yeem tiv thaiv lub rooj tsav xwm hauv Circuit Court lossis lub hwj chim tswj nws tus kheej los ntawm kev kub hnyiab vim muaj ntau dhau tam sim no thaum kho thiab kho lub voj voog nrog luv luv Circuit Court txhaum.
(3) Nrog lub tshuab hluav taws xob tswj tsis siv neeg, cov kiv cua kub dissipation tau txais kev ua haujlwm thaum lub tshuab hluav taws xob hloov hluav taws xob ntau tshaj 55 degree.
txoj cai ua haujlwm
Lub ntsiab Circuit Court: muaj li ntawm 1M31 7, Q1, Q2. Nws yog ib tug niaj hnub expansion daim ntawv thov Circuit Court. Tam sim no nrov high-power voltage regulator integrated circuit 1M338 tsis siv vim nws overcurrent tiv thaiv muaj nuj nqi yog rhiab heev, thiab nws yuav nkag mus rau hauv lub xeev tiv thaiv thaum nws tshaj 5A nyob rau hauv ib qho instant, thaum lub sij hawm pib tam sim no ntawm cov cuab yeej hluav taws xob me me (xws li me me. hluav taws xob xyaum thiab DC motors) feem ntau tshaj 5A Thiab nws tsis tuaj yeem nqa inductive load, uas kuv tau sim. Yog hais tias lub ammeter sampling resistor R6 yog ua los ntawm cov hlau tsis tu ncua, qhov kev tiv thaiv tus nqi tsawg dhau, txawm tias nws raug ntsuas los ntawm tus choj ua ntej, qhov kev tiv thaiv ntawm kev sib cuag (qhov taw tes solder) yuav dhau qhov kev ua yuam kev. A 0.12Ω cement resistor yog siv ntawm no, thiab qhov hluav taws xob poob los ntawm qhov tam sim no raug kho los ntawm RP3 thiab xa mus rau lub taub hau voltmeter nrog tag nrho cov nplai ntawm 2V, thiab tag nrho cov nplai tam sim no yog 20.{{15 }}A.
Tswj Circuit Court.
Lub Circuit Court tswj tam sim no tsis tu ncua yog tsim los ntawm qhov sib piv voltage. RP4 yog tam sim no hloov potentiometer. Qhov tseeb voltage siv (txog 2.5-2.6V) tsim los ntawm IC5 yog muab faib los ntawm RP3 thiab xa mus rau inverting input ntawm IC6. Cov qauv ntsuas tam sim no tsim los ntawm kev faib hluav taws xob ntawm RP4 yog xa mus rau qhov tsis yog inverting input davhlau ya nyob twg ntawm IC6. Yog tias qhov tseeb tam sim no tshaj qhov teeb tsa tus nqi tam sim no, IC6 tso tawm ib theem siab, Q4 tau qhib, lub peev xwm ntawm 1M317 hloov kho lub davhlau ya nyob twg poob → cov zis hluav taws xob poob → cov zis tam sim no poob mus txog rau qhov tam sim no sib npaug rau qhov teeb tsa tam sim no tus nqi. Nyob rau tib lub sijhawm, Q3 tau qhib, thiab lub teeb-emitting diode VD6 qhia tau hais tias nws nyob hauv lub xeev tam sim no.
Short-circuit tiv thaiv muaj nuj nqi: Nws muaj kev tiv thaiv zoo tshaj plaws, tab sis nws tsis tuaj yeem tiv thaiv lub zog txuas tam sim no thaum cov zis tawm luv luv.
Thaum luv luv-circuited, cov zis tam sim no ntau dua li cov nqi tam sim no, kom Q4 tau qhib tag nrho, thiab cov zis tawm yog qhov tsawg kawg nkaus tus nqi (txog 1.2V). Lub sijhawm no, qhov ntsuas luv-circuit tam sim no yog kwv yees li 4-5A. Txawm hais tias qhov luv-circuit tam sim no raug txwv, vim yog lub zog loj dissipation ntawm tam sim no-expanding hwj chim raj, nws tseem yog ib qho txaus ntshai rau lub sij hawm ntev. Nws yog qhov zoo tshaj rau nruab qhov tso zis hluav taws xob luv luv tiv thaiv fuse (5A).
J2 yog qhov chaw tam sim no / tso saib hloov pauv relay. Thaum nws nyob rau hauv txoj hauj lwm 1, qhov voltage poob ntawm tam sim no sampling resistor R6 yog kho los ntawm RP3 thiab xa mus rau lub ammeter kom pom qhov tseeb tam sim no. Thaum nyob rau hauv txoj hauj lwm 2, qhov voltage ntawm qhov tam sim no hloov potentiometer RP4 raug xa mus rau ammeter los tso saib cov nqi tam sim no. Lub ammeter yog lub taub hau voltmeter nrog tag nrho teev ntawm 2V. Lwm qhov kev sib piv yog cov kiv cua tswj Circuit Court, uas yog hysteresis comparator circuit. Lub voj voog hauv daim duab tuaj yeem pib lub kiv cua thaum qhov kub ntawm 55 degree, thiab nres lub kiv cua thaum nws qis dua 45 degree. Li no txo cov suab nrov thiab txhim kho lub neej ntawm tus kiv cua. Qhov kub tsis zoo coefficient thermistor nrog RH ntawm 820 ohms yuav tsum tau muab khi rau hauv lub dab dej kub. Kev khiav hauj lwm kub tuaj yeem raug xaiv los ntawm kev kho qhov sib thooj ntawm qhov sib piv ntawm hysteresis.
Lub teeb kov khawm tswj Circuit Court: Xav txog qhov kev xav zoo ntawm kev ua haujlwm, tsis yog siv cov nyees khawm zoo tib yam / khawm keyboards, nws siv lub teeb kov hloov ntxiv rau digital tswj circuit ntxiv rau relay hom.
Kev xaiv cov khoom siv
Lub voltmeter txais yuav lub taub hau voltmeter nrog tag nrho cov nplai ntawm 200V, thiab tus lej lej tom qab kaum tus lej teeb. Lub ammeter siv lub taub hau voltmeter nrog tag nrho cov nplai ntawm 2V, thiab tus lej lej tom qab ntau pua tus lej teeb (uas yog, qhov ntsuas tag nrho yog 20.00A).
Lub transformer txais ib lub zog zaus transformer ntawm 150W los yog saum toj no los yog lub nplhaib-zoo li tus nyuj tua hluav taws, thiab lub zog winding siv 1.4 hli enameled hlau.
J1 siv 12V relay nrog kev tiv tauj tam sim no ntau dua 10A. J2 txais JRX hom me relay.
RP1 thiab RP2 tsis tuaj yeem siv cov pa roj carbon zoo tib yam potentiometers vim tias qhov tam sim no loj dhau los ntawm lawv. Siv WX13-1 hom 1 hlau-qhov txhab potentiometers tuaj yeem ua rau lub neej ua haujlwm tau zoo. RP3 siv ntau tig precision trimming resistors. Q1 siv lub raj muaj zog NPN nrog Ic Ntau dua lossis sib npaug ntawm 10A thiab BVceo Ntau dua lossis sib npaug rau 60V, thiab Q2 siv lub raj PNP dav dav.
12V kiv cua siv 10 × 10cm meter kiv cua.
kev hloov kho Circuit Court
Kev sib dhos ua tiav. Tom qab qhov voltage thiab ammeter tso saib ib txwm, thiab qhov voltage yog adjustable, ua raws li nram no debugging:
Txuas lub 10Ω, 5W load tsis kam thiab digital multimeter (nyob rau hauv qhov siab tam sim no ntau) rau cov zis ntawm lub hwj huam mov, kho cov zis voltage kom lub multimeter qhia 1.00A, thiab kho RP3 kom cov hauv zos ammeter qhia 1.00A.
Txuas lub 10Ω, 5W load resistor rau qhov tso zis davhlau ya nyob twg, teeb K2 mus rau 2, teeb tsa qhov tam sim no tas li ntawm tus nqi (piv txwv li, 0.50A), tom qab ntawd teeb K2 rau 1, maj mam nce qhov tso zis voltage , thiab cov load tam sim no yuav nce Thaum tus nqi tau teeb tsa, qhov voltage thiab tam sim no yuav tsis sawv thiab nyob twj ywm ntawm tus nqi tam sim no. Lub sijhawm no, cov haujlwm tsis tu ncua tam sim no los ua si.
Short-circuit test: Short-circuit the output terminal, ammeter will display between 4-5A, and VD6 will light up at the same time, qhia tshaj-tam sim no.
