Taw qhia rau Cov Hluav Taws Xob Tawm Hluav Taws Xob: 8 Cov Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:26

Tsib xyoos dhau los thaum kuv tau pib ua thawj zaug nrog Arduino thiab Raspberry Pi Kuv tsis tau xav ntau txog cov khoom siv hluav taws xob, lub sijhawm no lub zog hloov pauv los ntawm raspberry Pi thiab USB muab ntawm Arduino tau ntau dua txaus.

Tab sis tom qab qee lub sijhawm kuv xav paub thawb kuv kom txiav txim siab lwm txoj hauv kev siv hluav taws xob, thiab tom qab tsim ntau txoj haujlwm kuv raug yuam kom txiav txim siab txog qhov sib txawv thiab yog tias tuaj yeem kho tau DC lub zog qhov chaw.

Tshwj xeeb tshaj yog thaum koj ua tiav koj tus qauv koj yuav xav tau tsim kom muaj qhov ruaj khov dua ntawm koj txoj haujlwm, thiab rau qhov ntawd koj yuav tsum xav txog yuav ua li cas hais txog kev muab lub zog rau nws.

Hauv qhov kev qhia no Kuv yuav piav qhia koj li cas koj tuaj yeem tsim koj tus kheej cov khoom siv hluav taws xob tawm nrog siv dav thiab pheej yig tus tswj hluav taws xob IC (LM78XX, LM3XX, PSM-165 thiab lwm yam). Koj yuav kawm paub txog lawv txoj haujlwm thiab siv rau koj tus kheej cov haujlwm.

Kauj Ruam 1: Tsim Kev Xav

Cov theem Voltage ntau

Muaj ntau ntau qib kev ntsuas hluav taws xob uas koj tsim yuav xav tau:

• 3.3 Volts DC-Qhov no yog qhov hluav taws xob siv los ntawm Raspberry PI thiab cov cuab yeej siv hluav taws xob qis.
• 5 Volts DC - Qhov no yog tus qauv TTL (Transistor Transistor Logic) qhov hluav taws xob siv los ntawm cov cuab yeej digital.
• 12 Volts DC -siv rau DC, servo thiab stepper motors.
• 24/48 Volts DC - siv dav hauv CNC thiab 3D Luam cov phiaj xwm.

Koj yuav tsum txiav txim siab hauv koj tus qauv tsim uas cov theem kev xav ntawm lub zog yuav tsum tau tswj kom raug. Piv txwv rau cov khoom siv nrog TTL qhov hluav taws xob qhov hluav taws xob xav tau yuav tsum nyob nruab nrab ntawm 4.75 thiab 5.25 volts, txwv tsis pub muaj qhov sib txawv ntawm qhov hluav taws xob yuav ua rau cov khoom siv logic tsis ua haujlwm raug lossis tseem ua rau koj puas.

Hauv kev sib piv rau cov cuab yeej siv qib siab lub zog siv hluav taws xob rau lub cav, LEDs thiab lwm yam khoom siv hluav taws xob tuaj yeem hloov pauv ntau yam. Tsis tas li ntawd koj yuav tsum xav txog cov kev xav tau tam sim no ntawm txoj haujlwm. Tshwj xeeb tshaj yog cov motors tuaj yeem ua rau qhov teeb meem tam sim no hloov pauv thiab koj yuav tsum tsim koj lub zog xa hluav taws xob kom haum rau qhov xwm txheej "phem tshaj" uas txhua lub cav tau ua haujlwm tas li.

Koj yuav tsum siv txoj hauv kev sib txawv rau kev tswj hwm qhov hluav taws xob rau txoj kab siv hluav taws xob thiab siv lub roj teeb tsim, vim tias cov roj teeb theem yuav hloov pauv raws li lub roj teeb tawm.

Lwm qhov tseem ceeb ntawm kev tsim qauv tswj hluav taws xob yog qhov ua tau zoo - tshwj xeeb tshaj yog hauv cov phiaj xwm siv roj teeb koj yuav tsum txo hwj chim poob mus rau qhov tsawg kawg nkaus.

NCO NTSOOV: Hauv ntau lub tebchaws ib tus neeg tsis tuaj yeem ua haujlwm raug cai nrog cov hluav taws xob siab dua 50V AC yam tsis muaj ntawv tso cai. Txhua qhov ua yuam kev los ntawm ib tus neeg ua haujlwm nrog lub zog ua kom tuag tuaj yeem ua rau lawv tus kheej tuag, lossis ntawm lwm tus neeg. Vim li no kuv tsuas yog piav qhia DC lub zog xa khoom tsim nrog qhov ntsuas hluav taws xob qis dua 60 V DC.

Kauj Ruam 2: Hom Voltage Regulators

Muaj ob hom tseem ceeb ntawm cov tswj hluav taws xob:

• linear voltage regulators uas pheej yig tshaj thiab yooj yim siv
• hloov cov ntsuas hluav taws xob uas ua haujlwm tau zoo dua li cov ntsuas hluav taws xob ncaj qha, tab sis kim dua thiab lawv xav tau cov qauv tsim hluav taws xob ntau dua.

Hauv qhov kev qhia no peb yuav ua haujlwm nrog cov ntsuas hluav taws xob tawm.

Cov yam ntxwv hluav taws xob ntawm cov ntsuas hluav taws xob tawm

Qhov hluav taws xob poob qis hauv kab tswj hwm tus lej yog sib npaug rau lub zog IC uas tau tawg, lossis nrog rau lwm lo lus lub zog poob vim yog cov cua sov ua haujlwm.

Rau lub zog tso tawm hauv cov kab tswj kab hauv qab no sib npaug tuaj yeem siv tau:

Lub zog = (VInput - VOutput) x I

L7805 tus tswj hwm txoj kab yuav tsum tso tawm tsawg kawg 2 watts yog tias nws yuav xa 1 A load (2 V qhov hluav taws xob poob qis 1 A).

Nrog kev nce ntawm qhov sib txawv ntawm qhov sib txawv ntawm cov tswv yim thiab cov hluav taws xob tso tawm - lub zog xa tawm nce ntxiv ib yam. Lub ntsiab lus, piv txwv li, thaum 7 qhov chaw tswj hwm rau 5 volts xa 1 amp yuav yaj 2 watts los ntawm tus tswj kab, 12 V DC qhov chaw tswj rau 5 volts xa tib lub tam sim no yuav tawg 5 watts, ua tus tswj tsuas yog 50 % muaj txiaj ntsig

Qhov ntsuas tseem ceeb tom ntej yog "Thermal Resistance" hauv chav ntawm ° C/W (° C per Watt).

Qhov ntsuas ntsuas no qhia tus lej ntawm qib uas lub nti yuav sov dua qhov cua sov ib puag ncig, rau txhua lub watt ntawm lub zog nws yuav tsum yaj. Tsuas yog suav qhov suav lub zog tso tawm los ntawm Thermal Kuj thiab qhov ntawd yuav qhia koj ntau npaum li cas tus tswj kab hluav taws xob yuav ua kom sov nyob hauv qab tus nqi zog ntawd:

Hwj chim x Kub Kuj = Kub Saum Ntuj Ceeb Tsheej

Piv txwv li tus 7805 tus tswj hwm muaj Kev Tiv Thaiv Kub ntawm 50 ° C / Watt. Qhov no txhais tau tias yog koj tus tswj hwm tau tawm mus:

• 1 watt, nws yuav sov li 50 ° C.
• .2 watts nws yuav sov li 100 ° C.

NCO TSEG: Thaum npaj phiaj xwm phiaj xwm sim kwv yees qhov xav tau tam sim no thiab txo qhov sib txawv qhov hluav taws xob kom tsawg. Piv txwv li 78XX tus ntsuas hluav taws xob tso tawm muaj 2 V qhov hluav taws xob poob qis (min. Qhov ntsuas hluav taws xob yog Vin = 5 + 2 = 7 V DC), yog li koj tuaj yeem siv 7, 5 lossis 9 V DC fais fab mov.

Kev suav ua haujlwm tau zoo

Raws li kev txiav txim siab tias qhov tso tawm tam sim no sib npaug rau cov tswv yim tam sim no rau tus tswj kab tawm ces peb yuav tau txais qhov sib npaug yooj yim:

Kev Ua Tau Zoo = Vout / Vin

Piv txwv li, cia peb hais tias koj muaj 12 V ntawm cov tswv yim thiab xav kom tso tawm 5 V ntawm 1 A ntawm kev thauj khoom tam sim no, tom qab ntawd qhov ua tau zoo rau tus tswj hwm txoj kab yuav tsuas yog (5 V / 12 V) x 100 % = 41 %. Qhov no txhais tau tias tsuas yog 41 % ntawm lub zog los ntawm kev tawm tswv yim raug xa mus rau cov zis, thiab lub zog uas seem yuav poob thaum tshav kub!

Kauj Ruam 3: 78XX Tus Tswj Kab Tawm

78XX tus tswj hwm qhov hluav taws xob yog 3-pin cov cuab yeej muaj nyob hauv ntau lub pob khoom sib txawv, los ntawm cov pob khoom siv hluav taws xob loj (T220) mus rau cov khoom me me saum npoo nws yog qhov ntsuas hluav taws xob zoo. 79XX series yog qhov sib npaug tsis zoo qhov ntsuas hluav taws xob.

78XX series cov tswj hwm muab kev tswj hwm qhov hluav taws xob ruaj khov los ntawm 5 txog 24 V. Ob tus lej kawg ntawm IC tus lej lej qhia txog qhov tso zis hluav taws xob ntawm lub cuab yeej. Qhov no txhais tau tias, piv txwv li, 7805 yog tus tswj hwm 5 volt zoo, 7812 yog tus tswj hwm 12 volt zoo.

Cov ntsuas hluav taws xob no ncaj qha rau pem hauv ntej - txuas L8705 thiab ob peb lub tshuab hluav taws xob hluav taws xob hla cov tswv yim thiab tso tawm, thiab koj tsim cov tswj hluav taws xob yooj yim rau 5 V Arduino cov haujlwm.

Cov kauj ruam tseem ceeb yog txhawm rau txheeb xyuas cov ntawv txheeb rau tus pin-outs thiab cov chaw tsim khoom pom zoo.

78XX (qhov zoo) tus tswj hwm siv cov hauv qab no:

1. INPUT-unregulated DC input Vin
2. KEV SIB HAIS (GROUND)
3. OUTPUT -regulated DC tso tawm Vout

Ib yam uas yuav tsum nco ntsoov txog TO-220 rooj plaub ntawm cov tswj hwm qhov hluav taws xob no yog tias rooj plaub txuas nrog hluav taws xob txuas rau tus pin nruab nrab (tus pin 2). Ntawm 78XX series uas txhais tau hais tias rooj plaub tau pib.

Hom kev tswj hwm txoj kab no muaj 2 V tso tawm qhov hluav taws xob, vim tias nrog 5V tso tawm ntawm 1A, koj yuav tsum muaj tsawg kawg 2.5 V DC lub taub hau hluav taws xob (piv txwv li, 5V + 2.5V = 7.5V DC input).

Cov chaw tsim khoom lag luam pom zoo rau lub tshuab ua kom sib luag yog CInput = 0.33 µF thiab COutput = 0.1 µF, tab sis kev coj ua dav dav yog 100 µF capacitor ntawm cov tswv yim thiab tso tawm Nws yog qhov kev daws teeb meem zoo rau qhov xwm txheej tsis zoo, thiab cov capacitors pab daws teeb meem kev hloov pauv sai thiab hloov pauv hauv cov khoom siv.

Nyob rau hauv rooj plaub uas cov khoom poob qis dua qhov pib ntawm 2 V- cov khoom siv hluav taws xob yuav ruaj khov cov khoom siv kom ntseeg tau tias qhov no tsis tshwm sim. Yog tias koj qhov project dos tsis muaj kev hloov pauv zoo li no, tom qab ntawd koj tuaj yeem ua haujlwm nrog cov chaw tsim khoom pom zoo.

Cov kab hluav taws xob txoj kab hluav taws xob yooj yim tsuas yog L7805 tus tswj hluav taws xob thiab ob lub peev xwm, tab sis peb tuaj yeem hloov kho qhov Circuit Court no los tsim qee qhov kev siv hluav taws xob ntau ntxiv nrog qee qib kev tiv thaiv thiab qhov pom pom.

Yog tias koj xav faib koj txoj haujlwm ces kuv yuav hais qhia ntxiv ob peb yam ntxiv no txhawm rau tiv thaiv kev tsis zoo yav tom ntej nrog cov neeg siv khoom.

Kauj Ruam 4: Hloov kho 7805 Circuit

Ua ntej koj tuaj yeem siv qhov hloov pauv mus rau lub zog hluav taws xob hauv lossis tawm.

Ib qho ntxiv, koj tuaj yeem tso lub diode (D1), txuas hauv qhov tsis sib xws ntawm cov zis thiab cov tswv yim ntawm tus tswj hwm. Yog tias muaj cov khoom siv hluav taws xob hauv lub nra, lossis txawm tias lub tshuab hluav taws xob, qhov poob ntawm cov tswv yim tuaj yeem ua rau qhov rov qab hluav taws xob, uas tuaj yeem rhuav tshem tus tswj hwm. Lub diode hla dhau ib qho tam sim no.

Cov capacitors ntxiv ua raws li hom lim kawg. Lawv yuav tsum ntsuas ntsuas rau qhov tso zis hluav taws xob, tab sis yuav tsum siab txaus kom haum rau cov tswv yim me ntsis ntawm kev nyab xeeb (piv txwv li, 16 25 V). Lawv yeej nyob ntawm seb hom kev thauj khoom uas koj xav tau, thiab tuaj yeem raug tso tawm rau qhov ntsaws DC, tab sis 100uF rau C1 thiab C2, thiab 1uF rau C4 (thiab C3) yuav yog qhov pib zoo.

Ib qho ntxiv koj tuaj yeem ntxiv LED thiab qhov tsim nyog tam sim no-txwv tus tiv thaiv kom muab lub teeb pom kev uas yog qhov muaj txiaj ntsig zoo rau kev ntsuas lub zog tsis ua haujlwm; thaum lub tshuab hluav taws xob txuas hluav taws xob LED yog ON txwv tsis pub saib rau qee qhov ua tsis tiav hauv koj lub Circuit Court.

Cov tswj hwm hluav taws xob feem ntau muaj kev tiv thaiv hluav taws xob uas tiv thaiv cov chips los ntawm kev ua kom sov thiab yog tias nws kub dhau, nws tso qhov hluav taws xob tso tawm thiab yog li txwv qhov tso tawm tam sim no kom lub cuab yeej tsis raug puas tsuaj los ntawm tshav kub. Cov tswj hluav taws xob hauv TO-220 pob kuj tseem muaj lub qhov tso rau lub rhaub dej txuas, thiab kuv yuav qhia tias koj yuav tsum tau siv nws txhawm rau txhawm rau ua kom muaj cua sov zoo.

Kauj Ruam 5: Muaj Hwj Chim Ntau Los Ntawm 78XX

Feem ntau ntawm 78XX tus tswj hwm tau txwv rau qhov tso tawm tam sim no ntawm 1 - 1.5 A. Yog tias qhov tso tawm tam sim no ntawm IC tus tswj hwm tshaj nws qhov kev tso cai siab tshaj plaws, nws sab hauv dhau transistor yuav ua rau lub zog ntau dua li nws tuaj yeem tiv taus, uas yuav ua rau mus rau kaw.

Rau cov ntawv thov uas xav tau ntau dua li qhov siab tshaj qhov tso cai tam sim no ntawm tus tswj hwm, ib qho transistor sab nraud tuaj yeem siv los nce qhov tso tawm tam sim no. Daim duab los ntawm FAIRCHILD Semiconductor piav qhia xws li kev teeb tsa. Lub voj voog no muaj peev xwm ua kom muaj hluav taws xob ntau dua (txog 10 A) rau lub nra tab sis tseem khaws cia cov cua sov kaw thiab tiv thaiv luv Circuit Court ntawm IC tus tswj hwm.

BD536 fais fab transistor tau pom zoo los ntawm cov chaw tsim khoom.

Kauj Ruam 6: LDO Cov Tswj Hluav Taws Xob

L7805 yog cov cuab yeej yooj yim heev uas muaj tus txheeb ze tso tawm qhov siab.

Qee qhov kev ntsuas hluav taws xob tawm, yog li hu ua qis-tawm (LDO), muaj qhov tso hluav taws xob me dua li 2V ntawm 7805. Piv txwv li LM2937 lossis LM2940CT-5.0 muaj qhov tso tawm 0.5V, vim li ntawd koj lub zog hluav taws xob yuav muaj kev ua haujlwm siab dua, thiab koj tuaj yeem siv nws hauv cov phiaj xwm nrog roj teeb lub zog.

Qhov tsawg kawg nkaus Vin-Vout sib txawv uas tus tswj kab tawm tuaj yeem ua haujlwm tau hu ua qhov tso tawm qhov hluav taws xob. Yog tias qhov sib txawv ntawm Vin thiab Vout poob qis dua qhov tso tawm qhov hluav taws xob, tom qab ntawd tus tswj hwm nyob hauv hom kev tso tawm.

Cov tswj kev tso tawm qis muaj qhov sib txawv qis heev ntawm cov tswv yim thiab cov hluav taws xob tso tawm. Tshwj xeeb tshaj yog LM2940CT-5.0 linear regulators voltage sib txawv tuaj yeem ncav cuag tsawg dua 0.5 volt ua ntej cov cuab yeej "poob tawm". Rau kev ua haujlwm ib txwm, qhov ntsuas hluav taws xob yuav tsum yog 0.5 V siab dua qhov tso tawm.

Cov tswj hwm qhov hluav taws xob muaj tib yam T220 daim ntawv zoo li L7805 nrog rau ib qho kev teeb tsa - tawm tswv yim ntawm sab laug, av hauv nruab nrab, thiab tso tawm sab xis (thaum saib los ntawm sab xub ntiag). Raws li qhov tshwm sim koj tuaj yeem siv tib lub Circuit Court. Kev tsim cov lus pom zoo rau cov capacitors yog CInput = 0.47 µF thiab COutput = 22 µF.

Ib qho teeb meem loj yog tias "kev tso tawm qis" tus tswj hwm tus nqi kim dua (txawm tias txog kaum zaug) hauv kev sib piv rau 7805 series.

Kauj Ruam 7: Tswj LM317 Cov Khoom Siv Hluav Taws Xob

LM317 yog qhov ntsuas qhov ntsuas hluav taws xob zoo nrog qhov hloov pauv tau, muaj peev xwm muab cov khoom tso tawm tam sim no ntau dua 1.5 A tshaj qhov tso tawm qhov hluav taws xob ntau ntawm 1.2–37 V.

. Thawj ob tsab ntawv qhia txog tus neeg tsim khoom nyiam, xws li "LM", sawv rau "linear monolithic". Nws yog tus tswj hluav taws xob nrog qhov hloov pauv tau thiab yog li nws muaj txiaj ntsig zoo hauv cov xwm txheej uas koj xav tau qhov tsis siv hluav taws xob tsis zoo. Hom 78xx yog tus tswj qhov hluav taws xob zoo, lossis 79xx yog cov tswj qhov hluav taws xob tsis zoo, qhov twg "xx" sawv cev rau qhov hluav taws xob ntawm cov khoom siv.

Cov zis hluav taws xob ntau yog nyob nruab nrab ntawm 1.2 V txog 37 V, thiab tuaj yeem siv los txhawb koj li Raspberry Pi, Arduino lossis DC Motors Shield. LM3XX muaj tib qho kev tawm tswv yim/tso tawm qhov sib txawv raws li 78XX - cov tswv yim yuav tsum yog yam tsawg 2.5 V siab dua qhov tso zis.

Raws li nrog 78XX series cov tswj hwm LM317 yog peb tus pin ntaus ntawv. Tab sis cov xov hlau sib txawv me ntsis.

Qhov tseem ceeb kom nco txog LM317 kev sib txuas yog ob tus tiv thaiv R1 thiab R2 uas muab qhov ntsuas hluav taws xob siv rau tus tswj hwm; qhov ntsuas hluav taws xob siv no txiav txim siab qhov hluav taws xob tso tawm. Koj tuaj yeem suav cov resistor qhov tseem ceeb raws li hauv qab no:

Vout = VREF x (R2/R1) + IAdj x R2

IAdj feem ntau yog 50 µA thiab tsis tsim nyog nyob rau hauv feem ntau daim ntawv thov, thiab VREF yog 1.25 V - qhov tsawg kawg nkaus tso zis hluav taws xob.

Yog tias peb tsis quav ntsej IAdj ces peb cov kab zauv tuaj yeem yooj yim rau

Vout = 1.25 x (1 + R2/R1)

Yog tias peb yuav siv R1 240 Ω thiab R2 nrog 1 kΩ ces peb yuav tau txais cov zis voltage ntawm Vout = 1.25 (1+0/240) = 1.25 V.

Thaum peb yuav tig lub pob qhov rooj kom puv rau lwm txoj kev ces peb yuav tau txais Vout = 1.25 (1+2000/240) = 11.6 V raws li qhov tso tawm qhov hluav taws xob.

Yog tias koj xav tau cov zis hluav taws xob siab dua koj yuav tsum hloov R1 nrog 100 Ω resistor.

Circuit piav qhia:

• R1 thiab R2 yuav tsum tau teeb tsa qhov hluav taws xob tso tawm. CAdj raug pom zoo los txhim kho ripple rejection. Nws tiv thaiv kev ua kom nrov nrov ntawm lub ripple raws li qhov hluav taws xob tso tawm tau hloov kho siab dua.
• C1 raug pom zoo, tshwj xeeb tshaj yog tias tus tswj hwm tsis nyob ze rau lub zog-muab cov lim lim. 0.1-µF lossis 1-µF ceramic lossis tantalum capacitor muab kev hla dhau txaus rau feem ntau daim ntawv thov, tshwj xeeb tshaj yog thaum hloov kho thiab tso tawm cov capacitors.
• C2 txhim kho kev teb sai, tab sis tsis xav tau kev ruaj ntseg.
• Kev tiv thaiv diode D2 raug pom zoo yog tias siv CAdj. Lub diode muab txoj hauv kev tso tawm qis los tiv thaiv lub capacitor los ntawm kev tso tawm mus rau hauv cov zis ntawm tus tswj hwm.
• Kev tiv thaiv diode D1 raug pom zoo yog siv C2. Lub diode muab txoj hauv kev tso tawm qis los tiv thaiv lub capacitor los ntawm kev tso tawm mus rau hauv cov zis ntawm tus tswj hwm.

Kauj Ruam 8: Cov ntsiab lus

Cov cai tswj kab tawm muaj txiaj ntsig yog tias:

• Cov tswv yim rau cov zis hluav taws xob sib txawv me me
• Koj muaj qhov thauj khoom tsawg
• Koj xav tau qhov hluav taws xob tso zis huv heev
• Koj yuav tsum khaws cov qauv tsim kom yooj yim thiab pheej yig li sai tau.

Yog li ntawd, tsis yog tsuas yog cov tswj hwm txoj kab siv tau yooj yim dua, tab sis lawv muab lub zog tso zis ntau dua piv rau kev hloov pauv kev tswj hwm, tsis muaj ripple, spikes, lossis suab nrov ntawm txhua yam. Hauv cov ntsiab lus, tshwj tsis yog lub zog xa hluav taws xob siab dhau lossis koj xav tau tus tswj hwm nce qib, tus tswj kab tawm yuav yog koj qhov kev xaiv zoo tshaj.