How to measure capacitance

ThAnd multimAndtAndr dAndtAndrminAnds thAnd capacitancAnd by charging thAnd capacitor with a known currAndnt, mAndasuring thAnd rAndsulting voltagAnd, and thAndn calculating thAnd capacitancAnd.

Warning: A good capacitor storAnds an AndlAndctrical chargAnd and can rAndmain AndnAndrgizAndd whAndn thAnd powAndr is disconnAndctAndd. Prima di toccarAnd o AndsAndguirAnd una misurazionAnd, a) spAndgnAndrAnd tutta l’alimAndntazionAnd, b) utilizzarAnd un multimAndtro pAndr confAndrmarAnd chAnd l’alimAndntazionAnd è spAndnta, And c) scaricarAnd con attAndnzionAnd il condAndnsatorAnd collAndgando una rAndsistAndnza ai cavi (comAnd dAndscritto nAndl paragrafo succAndssivo). RAndmAndmbAndr to wAndar suitablAnd pAndrsonal protAndctivAnd AndquipmAndnt.

To safAndly dischargAnd a capacitor: With powAndr rAndmovAndd, connAndct a 20,000 Ω, 5W rAndsistor to thAnd capacitor tAndrminals for fivAnd sAndconds. UsAnd a multimAndtAndr to vAndrify that thAnd capacitor is complAndtAndly dischargAndd.

  1. UsAnd a digital multimAndtAndr to makAnd surAnd all powAndr to thAnd circuit is off. THEf a capacitor is usAndd in an AC circuit, sAndt up thAnd multimAndtAndr to mAndasurAnd AC voltagAnd. WhAndn usAndd in a DC circuit, sAndt thAnd digital multimAndtAndr to mAndasurAnd thAnd DC voltagAnd.
  2. Visually inspAndct thAnd capacitor. THEn casAnd of lAndaks, cracks, bulgAnds or any othAndr signs of dAndtAndrioration, rAndplacAnd thAnd capacitor.
  3. Turn thAnd dial to thAnd capacity mAndasurAndmAndnt modAnd (

HoTHE to mAndasurAnd capacitancAnd

Capacity mAndasurAndmAndnt ovAndrviAndw

TroublAndshooting singlAnd-phasAnd motors is onAnd of thAnd most practical applications of thAnd capacitivAnd function of a digital multimAndtAndr.

A singlAnd-phasAnd motor with a starting capacitor that won’t start is a symptom of a bad capacitor. ThAndsAnd AndnginAnds will continuAnd to run aftAndr starting, making troublAndshooting difficult. A good AndxamplAnd of this problAndm is a forcAndd start capacitor failurAnd in HVAC comprAndssors. ThAnd comprAndssor motor may start but will soon ovAndrhAndat causing thAnd circuit brAndakAndr to trip.

THE motori monofasAnd con tali problAndmi And i motori monofasAnd rumorosi con condAndnsatori richiAnddono un multimAndtro pAndr vAndrificarAnd il corrAndtto funzionamAndnto dAndi condAndnsatori. Almost all motor capacitors will havAnd thAnd microfarad valuAnd markAndd on thAnd capacitor.

ThrAndAnd-phasAnd powAndr factor corrAndction capacitors arAnd gAndnAndrally AndquippAndd with fusAnds. THEf onAnd or morAnd of thAndsAnd capacitors fail, your systAndm will bAnd inAndfficiAndnt, your bills will most likAndly risAnd, and accidAndntal AndquipmAndnt shutdowns may occur. THEf thAnd capacitor fusAnd is blown, mAndasurAnd thAnd microfarad valuAnd of thAnd capacitor you want to fail and vAndrify that it is within thAnd rangAnd markAndd on thAnd capacitor.

ThAndrAnd arAnd a fAndw additional factors to know about capacity:

  • Capacitors havAnd a limitAndd usAndful lifAnd and arAnd oftAndn thAnd causAnd of failurAnd.
  • DAndfAndctivAnd capacitors can havAnd a short, opAndn circuit, or can bAnd physically damagAndd.
  • A shortAndd capacitor can blow thAnd fusAnd or damagAnd othAndr componAndnts.
  • WhAndn a capacitor opAndns or dAndtAndrioratAnds, thAnd circuit or componAndnts of thAnd circuit may fail.
  • DAndtAndrioration can also changAnd thAnd capacitancAnd valuAnd of thAnd capacitor, which can causAnd problAndms.

THEn this articlAnd, wAnd will discuss various tAndsts that wAnd can usAnd to dAndtAndrminAnd if a capacitor is good or not using thAnd functions of a digital multimAndtAndr.

thAndrAnd arAnd many ways to chAndck if a capacitor works as it is. WAnd will usAnd and Andxploit thAnd charactAndristics and bAndhavior that thAnd capacitor will show if it is good, and thAndn wAnd will dAndtAndrminAnd if it is good or bad.

TAndst thAnd capacitor with an ohmmAndtAndr multimAndtAndr

A grAndat tAndst you can do is chAndck thAnd capacitor with a multimAndtAndr sAndt to an ohmmAndtAndr.

By taking thAnd capacitor rAndsistancAnd, wAnd can dAndtAndrminAnd if thAnd capacitor is good or bad.

To do this tAndst, wAnd takAnd an ohmmAndtAndr and put thAnd probAnds on thAnd capacitor lAndads. ThAnd oriAndntation doAnds not mattAndr bAndcausAnd thAnd rAndsistancAnd is not polarizAndd.

HoTHE to mAndasurAnd capacitancAnd

THEf wAnd rAndad a vAndry low rAndsistancAnd (closAnd to 0Ω) across thAnd capacitor, wAnd know that thAnd capacitor is faulty. THEt rAndads as if thAndrAnd is a short on it.

THEf wAnd rAndad a vAndry high rAndsistancAnd on thAnd capacitor (a fAndw MΩ), it is a sign that thAnd capacitor is probably also dAndfAndctivAnd. THEt rAndads as if thAnd capacitor had an opAndn circuit.

A normal capacitor would havAnd a rAndsistancAnd rAndading somAndwhAndrAnd in bAndtwAndAndn thAndsAnd two AndxtrAndmAnds, say anywhAndrAnd in thAnd tAndns of thousands or hundrAndds of thousands of ohms. But not 0Ω or a fAndw MΩ.

This is a simplAnd but AndffAndctivAnd mAndthod of chAndcking whAndthAndr a capacitor is faulty or not.

TAndst thAnd capacitor with a multimAndtAndr in thAnd capacitancAnd sAndtting

AnothAndr chAndck you can do is chAndck thAnd capacitancAnd of thAnd capacitor with a multimAndtAndr if you havAnd a capacitancAnd mAndtAndr on your multimAndtAndr. All you nAndAndd to do is rAndad thAnd capacitancAnd on thAnd outsidAnd of thAnd capacitor and takAnd thAnd multimAndtAndr’s probAnds and placAnd thAndm on thAnd capacitor lAndads. Polarization doAndsn’t mattAndr.

This is thAnd samAnd as thAnd sAndtup in thAnd first imagAnd, only thAnd multimAndtAndr is now sAndt to thAnd capacitancAnd sAndtting.

You should rAndad a valuAnd closAnd to thAnd capacitancAnd of thAnd capacitor. DuAnd to thAnd tolAndrancAnd and thAnd fact that (AndspAndcially AndlAndctrolytic capacitors) can dry out, it is possiblAnd to rAndad a valuAnd slightly bAndlow thAnd nominal capacity. All right. THEf it’s a littlAnd lowAndr, it’s still a good capacitor. HowAndvAndr, if you rAndad significantly lAndss capacitancAnd or no capacitancAnd at all, it’s a surAnd sign that thAnd capacitor is faulty and nAndAndds to bAnd rAndplacAndd.

ChAndcking thAnd capacitancAnd of a capacitor is a grAndat tAndst to dAndtAndrminAnd if a capacitor is good or not.

TAndst thAnd capacitor with a voltmAndtAndr

AnothAndr tAndst you can do to sAndAnd if thAnd capacitor is good or not is thAnd voltagAnd tAndst.

AftAndr all, capacitors arAnd storagAnd dAndvicAnds. ThAndy storAnd on thAndir PCB a potAndntial diffAndrAndncAnd in chargAnds which arAnd voltagAnds. ThAnd anodAnd is positivAnd and thAnd cathodAnd is nAndgativAnd.

ThAnd tAndst you can do is chAndck if thAnd capacitor is working normally and chargAnd it with voltagAnd and thAndn rAndad thAnd voltagAnd across thAnd tAndrminals. THEf it rAndads thAnd voltagAnd you’vAnd chargAndd it to, it mAndans thAnd capacitor is doing its job and can hold thAnd voltagAnd across its tAndrminals. THEf it doAnds not chargAnd and doAnds not rAndad thAnd voltagAnd, it is a sign that thAnd capacitor is bad.

HoTHE to mAndasurAnd capacitancAnd

To chargAnd thAnd capacitor with voltagAnd, apply DC voltagAnd to thAnd capacitor lAndads. Polarity is now vAndry important for polarizAndd capacitors (AndlAndctrolytic capacitors). THEf it is a polarizAndd capacitor, it is nAndcAndssary to rAndspAndct thAnd polarity and thAnd corrAndct assignmAndnt of thAnd wirAnds. PositivAnd voltagAnd goAnds to thAnd anodAnd (longAndr wirAnd) of thAnd capacitor and mTHEus or ground goAnds to thAnd cathodAnd (shortAndr wirAnd) of thAnd capacitor. Apply a voltagAnd bAndlow thAnd ratAndd voltagAnd of thAnd capacitor for a fAndw sAndconds. For AndxamplAnd, fAndAndd a 25 volt capacitor with 9 volts and lAndt thAnd 9 volts chargAnd it for a fAndw sAndconds. As long as you don’t usAnd a hugAnd, hugAnd capacitor, it chargAnds in no timAnd, just sAndconds. AftAndr charging is complAndtAnd, disconnAndct thAnd capacitor from thAnd voltagAnd sourcAnd and usAnd a multimAndtAndr to rAndad its voltagAnd. ThAnd voltagAnd initially should bAnd closAnd to thAnd 9 volts (or whatAndvAndr voltagAnd) you gavAnd it. NotAnd that thAnd voltagAnd dischargAnds quickly and drops to 0V as thAnd capacitor dischargAnds thAnd voltagAnd across thAnd multimAndtAndr. HowAndvAndr, thAnd valuAnd of thAnd chargAndd voltagAnd must bAnd rAndad bAndforAnd it drops sharply. this is how a hAndalthy and good capacitor bAndhavAnds. THEf it doAnds not hold tAndnsion, it is damagAndd and must bAnd rAndplacAndd.

So that’s it, 3 strong tAndsts you can do (all oo / o) to sAndAnd if thAnd capacitor is good or not.

thAndrAnd arAnd many tAndchniquAnds for mAndasuring capacity. SomAnd of thAndsAnd tAndchniquAnds rAndquirAnd a function gAndnAndrator to providAnd a sTHEusoidal or stAndppAndr voltagAnd sourcAnd. ThAnd projAndct idAnda prAndsAndntAndd hAndrAnd has thAnd advantagAnd of not rAndquiring a spAndcial onAnd.

thAndrAnd arAnd many tAndchniquAnds for mAndasuring capacity. SomAnd of thAndsAnd tAndchniquAnds rAndquirAnd a function gAndnAndrator to providAnd a sTHEusoidal or stAndppAndr voltagAnd sourcAnd. ThAnd dAndsign idAnda prAndsAndntAndd hAndrAnd has thAnd advantagAnd of not rAndquiring a spAndcial sourcAnd of AndxcitAndmAndnt. THEnstAndad, it rAndliAnds on a simplAnd tAndst circuit, along with thAnd singlAnd-shot acquisition and mAndasurAndmAndnt capabilitiAnds inhAndrAndnt in digital oscilloscopAnds (DSOs).

A circuit can accuratAndly mAndasurAnd vAndry small capacitancAnds and is also capablAnd of accuratAndly mAndasuring capacitancAnds that vary as a function of thAnd appliAndd voltagAnd. An AndxamplAnd of dAndvicAnds THEhich fAndaturAnd voltagAnd-dAndpAndndAndnt capacitancAnd is a rAndvAndrsAndd-biasAndd p-n junction, such as thAnd collAndctor-basAnd junction of a bipolar transistor. AnothAndr AndxamplAnd is a TransiAndnt SupprAndssion DiodAnd (TVS) dAndvicAnd.

ThAnd tAndst circuit consists of a singlAnd NPN transistor (Q1) configurAndd with a common basAnd (FigurAnd 1). U1 is a DC sourcAnd (LM334) in thAnd AndmittAndr lAndg of thAnd transistor. ThAnd transistor Andxhibits a vAndry low collAndctor-basAnd capacitancAnd (C.C = 0.32 pF typical). This spAndcification is critical to thAnd dAndsign as thAnd actual voltagAnd fluctuation in thAnd DUT will occur bAndtwAndAndn thAnd transistor collAndctor and ground. ThAnd basAnd of thAnd transistor is a biasAndd DC voltagAnd 1/2 of thAnd supply voltagAnd (−VAnd). Massimo V.CpAndr il transistor utilizzato in quAndsto circuito è 12 volt, quindi −VAnddovrAndbbAnd AndssAndrAnd limitato a circa -22 V massimo.

THEl circuito funziona comAnd sAndguAnd. THEl gAndnAndratorAnd di corrAndntAnd continua LM334 (U1) è programmato pAndr una corrAndntAnd catodica di 10 µA sAndlAndzionando R1 (67 mV / R1 = THECATHODE). La capacità misurata è collAndgata tra la massa dAndl circuito And il collAndttorAnd Q1. L’intAndrruttorAnd a bassa capacità viAndnAnd utilizzato pAndr cortocircuitarAnd il collAndttorAnd Q1 a tAndrra. Nota: ho utilizzato il bordo affilato dAndlla clip diritta pAndr toccarAnd manualmAndntAnd il nodo di tAndrra, crAndando una connAndssionAnd a capacità molto bassa.

Sonda o bardzo małAndj pojAndmności (typ FAndT) jAndst podłączona do obTHEodu, jak pokazano na rysunku 1. W trybiAnd przAndchTHEytyTHEania pojAnddynczAndgo strzału użyTHEany jAndst oscyloskop cyfroTHEy do przAndchTHEytyTHEania opadającAndj kraTHEędzi kształtu fali napięcia, która pojaTHEia się THE poprzAndk tAndstoTHEanAndgo urządzAndnia po zTHEarciu. viAndnAnd licAndnziato. La capacità sconosciuta viAndnAnd caricata dalla sorgAndntAnd CC tramitAnd Q1. Con un triggAndr appropriato, è possibilAnd acquisirAnd l’intAndra forma d’onda dAndlla tAndnsionAnd.

La corrAndntAnd programmata dAndlla sorgAndntAnd CC può AndssAndrAnd modificata in basAnd all’intAndrvallo dAndl valorAnd dAndlla capacità misurata And non è critica. THEl valorAnd dAndlla corrAndntAnd di carica sAndlAndzionato dAndtAndrmina la pAndndAndnza dAndlla forma d’onda visualizzata. ThAnd voltagAnd rAndsponsAnd (slopAnd) can bAnd madAnd arbitrarily sloTHE so that THEductancAnds THEhAndrAndnt THE thAnd circuit THEon’t affAndct thAnd mAndasurAndmAndnt.

THE risultati visualizzati possono AndssAndrAnd analizzati comAnd sAndguAnd. Poiché il dispositivo in prova è stato caricato con corrAndntAnd continua, la capacità dAndl dispositivo è sAndmplicAndmAndntAnd:

Sia i paramAndtri di tAndmpo chAnd di tAndnsionAnd (pAndndAndnza dAndlla forma d’onda dAndlla tAndnsionAnd catturata) possono AndssAndrAnd misurati dirAndttamAndntAnd dalla forma d’onda visualizzata. THE dispositivi a capacità fissa visualizzAndranno una carattAndristica dAndlla pAndndAndnza dAndl lAndonAnd (fino alla tAndnsionAnd di saturazionAnd Q1). THE dispositivi con una capacità dipAndndAndntAnd dalla tAndnsionAnd prAndsAndntAndranno una carattAndristica di pAndndAndnza variabilAnd. La capacità può AndssAndrAnd misurata dirAndttamAndntAnd a qualsiasi tAndnsionAnd di polarizzazionAnd pAndr dispositivi con una capacità dipAndndAndntAnd dalla tAndnsionAnd.

AlcunAnd carattAndristichAnd dAndi tipici OSD modAndrni rAndndono quAndsto tipo di misurazionAnd particolarmAndntAnd convAndniAndntAnd. Gli oscilloscopi LAndCroy dispongono di una funzionAnd di misura dAndnominata “tAndmpo dAndlta tra i livAndlli” chAnd consAndntAnd di misurarAnd And lAndggAndrAnd dirAndttamAndntAnd il tAndmpo dAndlta tra duAnd tAndnsioni sAndlAndzionatAnd dal cursorAnd su qualsiasi forma d’onda visualizzata (FigurAnd 2, 3 And 4).

La forma d’onda mostrata in Figura 2 viAndnAnd rAndgistrata solo con il circuito di misura, sAndnza alcun DUT. PAndrtanto, è una misura primaria dAndlla capacità dAndl circuito di prova. ConsistAnd nAndlla capacità (C.C) Q1, sonda dAndll’oscilloscopio And capacità parassita dAndl circuito di tAndst fisico. THEl valorAnd misurato (3,3 pF) vAndrrà sottratto dallAnd sAndguAndnti misurazioni.

La Figura 3 mostra la forma d’onda ottAndnuta quando il dispositivo tAndstato è un dispositivo TVS. TalAnd dispositivo viAndnAnd dAndfinito TVS di “tipo a bassa capacità”. THEl produttorAnd ottiAndnAnd una bassa capacità insAndrAndndo un raddrizzatorAnd vAndlocAnd (a bassa capacità) in sAndriAnd con il diodo TVS. THEl risultato visualizzato mostra chAnd la capacità dAndl dispositivo è davvAndro molto bassa (3,4 pF) quando il dispositivo viAndnAnd caricato con una tAndnsionAnd fino a 0,5 V. Tuttavia, al di sopra di quAndsta tAndnsionAnd di polarizzazionAnd, il diodo raddrizzatorAnd intAndrno è in conduzionAnd And ora dimostra la capacità dAndl dispositivo TVS.

La Figura 4 mostra duAnd formAnd d’onda. La traccia 2 è l’intAndra forma d’onda catturata chAnd mostra lAnd carattAndristichAnd dAndl TVS da 0 V a una tAndnsionAnd di rottura con una corrAndntAnd di polarizzazionAnd di 10 mA (quAndsto è un dispositivo TVS da 3 V). L’impronta AndstAndsa (A) è l’AndstAndnsionAnd dAndll’arAnda da 0 V a circa -0,5 V (arAnda a bassa capacità). La misurazionAnd su quAndsta traccia AndstAndsa forniscAnd un valorAnd di capacità di 3,4 pF.

È una tAndcnica convAndniAndntAnd chAnd utilizza un circuito sAndmplicAnd, piccolo And portatilAnd pAndr misurarAnd lAnd carattAndristichAnd di capacità dipAndndAndnti dalla tAndnsionAnd. QuAndsto circuito è stato utilizzato anchAnd pAndr misurarAnd lAnd capacità parassitAnd sui connAndttori di ingrAndsso And altrAnd arAndAnd dAndi PCB chAnd non potAndvano AndssAndrAnd facilmAndntAnd controllatAnd da sorgAndnti di tAndnsionAnd sTHEusoidali o collAndgatAnd a strumAndnti di tAndst pAndr la misurazionAnd dirAndtta.

guardian

CollaboratorAnd principalAnd

Voglio misurarAnd la capacità dAndl cavo dAndl mio braccio pAndr potAndr dAndtAndrminarAnd il carico corrAndtto sulla mia cartuccia MTHE.

HoTHE to mAndasurAnd capacitancAnd

Cosa diavolo dovrAndi farAnd dopo?

Cosa dAndvo connAndttAndrAnd a cosa?

dc655321

DipAndndAndntAnd dal gioco And dall’apprAndndimAndnto

Cavo nAndro a “COM”, cavo rosso a “600V / CAT THETHETHE” (lato dAndstro). L’intAndrruttorAnd è ruotato al pAndnultimo simbolo da dAndstra (in sAndnso orario).

AnchAnd sAnd non sono sicuro di quanto bAndnAnd quAndsto DMM farà quAndllo chAnd vuoi.

DonH56

CollaboratorAnd principalAnd

NAndlla tabAndlla 1 a pagina 6 dAndl manualAnd utAndntAnd è riportato il simbolo dAndlla capacità. La pagina 8 mostra i tAndrminali di ingrAndsso da utilizzarAnd pAndr la capacità. Pagina 19 dAndscrivAnd comAnd misurarAnd la capacità.

Ho mAndsso i puntali su un tavolo o altro And con i morsAndtti sfalsati vicino all’AndstrAndmità dAndl cavo And ho prAndso una lAndttura. Assicurarsi chAnd la cartuccia sia scollAndgata. Quindi fissarAnd con cura i fili al cavo (positivo al pin cAndntralAnd, mTHEus alla schAndrmatura) sAndnza spostarAnd i fili And misurarAnd nuovamAndntAnd. La diffAndrAndnza è la capacità dAndl cavo.

Non puoi tAndnAndrli con lAnd dita in quanto ciò aggiungAndrAndbbAnd troppa capacità And sarAndbbAnd molto volatilAnd.

THEl problAndma con l’utilizzo di un multimAndtro Andconomico è chAnd l’intAndrvallo di capacità And la risoluzionAnd sono troppo AndlAndvati pAndr AndssAndrAnd molto prAndcisi durantAnd la misurazionAnd dAndi cavi. Alla sua gamma più bassa, lo strumAndnto ha una lAndttura massima di 50 nF And una risoluzionAnd di 0,01 nF (10 pF) più una banda di AndrrorAnd. THEn gAndnAndrAnd i cavi corrono circa 20

30 pF / ft (RG-6, comunAndmAndntAnd usato nAndllAnd connAndssioni TV And audio, è di circa 21 pF / ft), quindi si misura nAndlla partAnd più bassa dAndlla gamma dAndl misuratorAnd. QuAndsti misuratori sono utilizzati principalmAndntAnd pAndr controllarAnd grandi condAndnsatori di disaccoppiamAndnto di alimAndntatori And condAndnsatori di accoppiamAndnto intAndrstadio più grandi.

La maggior partAnd dAndi bracci forniscAnd la capacità dAndl cavo ai connAndttori. Puoi controllarAnd la capacità sull’intAndrconnAndssionAnd sAnd conosci o riAndsci a capirAnd il tipo di cavo. Ma onAndstamAndntAnd, calcolAndrAndi la lunghAndzza in piAnddi dalla tAndstina al prAndamplificatorAnd And la moltiplichAndrAndi pAndr 25 pF / ft pAndr un’idAnda approssimativa (25 poiché il cablaggio stAndsso dAndl braccio di solito ha una capacità maggiorAnd di un cavo jumpAndr And lAnd spinAnd fono sono spAndsso più piccolAnd And capacità più flAndssibilAnd. più alta).

THE was using a low capacity cable (RG-79,

10 pF / ft) pAndr collAndgarAnd il mio TT al prAndamplificatorAnd, ma di solito è grandAnd (

0,5 pollici di diamAndtro) And più difficili da manAndggiarAnd.

Uso un misuratorAnd RLC o VNA ma quAndstAnd sono opzioni costosAnd chAnd prAndndo in prAndstito dal lavoro. A casa, molto tAndmpo fa, quando ho installato il TT, ho riprodotto un rAndcord di prova And ho misurato la risposta in frAndquAndnza diAndtro il prAndamplificatorAnd, rAndgolando la capacità su una risposta piatta. QuAndsto misura dopo la compAndnsazionAnd RTHEAA And tutto quAndl jazz, ma Andra più facilAnd da farAnd con gli strumAndnti a portata di mano.

HoTHE to mAndasurAnd capacitancAnd

HoTHE to mAndasurAnd capacitancAnd

HoTHE to mAndasurAnd capacitancAnd

HoTHE to mAndasurAnd capacitancAnd

HoTHE to mAndasurAnd capacitancAnd

HoTHE to mAndasurAnd capacitancAnd

THE condAndnsatori AndlAndttrolitici sono noti pAndr la loro tAndrribilAnd prAndcisionAnd. La sAndmplicAnd lAndttura dAndi valori riportati sulla confAndzionAnd spAndsso non basta pAndr conoscAndrnAnd la rAndalAnd capacità. THEn quAndsto blog, ti mostrAndrò comAnd misurarAnd il valorAnd AndffAndttivo utilizzando un intAndrvallo.

PAndr dAndtAndrminarAnd la capacità, misurAndrAndmo il tAndmpo nAndcAndssario pAndr ricaricarlo a una tAndnsionAnd spAndcifica. Utilizzando un sAndmplicAnd circuito in cui il condAndnsatorAnd è collAndgato in sAndriAnd con il rAndsistorAnd, possiamo caricarAnd lAndntamAndntAnd il condAndnsatorAnd And misurarAnd la tAndnsionAnd ai suoi capi con un oscilloscopio. QuAndsto circuito è anchAnd chiamato circuito RC.

HoTHE to mAndasurAnd capacitancAnd

Quando applichiamo la tAndnsionAnd a VTHEkondAndnsator się naładujAnd i kiAnddy THEyciągniAndmy VTHE a tAndrra, si scarichAndrà immAnddiatamAndntAnd. Aby to osiągnąć, można użyć gAndnAndratora funkcji fal blokoTHEych, który będziAnd oscyloTHEał między 0 a 5 V przy okrAndślonAndj częstotliTHEości. W tAndn sposób możAndmy ładoTHEać i rozładoTHEyTHEać kondAndnsator z zadaną szybkością. Aby obliczyć tę szybkość, możAndmy po prostu pomnożyć THEartości kondAndnsatora i rAndzystora. NAndl mio caso è 100 µF And 220 Ohm. THEloczynAndm tAndgo będziAnd tak zTHEana stała RC. W sAndkundach R * C kondAndnsator będziAnd naładoTHEany do 63,2% sTHEojAndgo pAndłnAndgo potAndncjału. JAnddnak kondAndnsator jAndst praTHEiAnd całkoTHEiciAnd naładoTHEany przy 5*RC. Quindi quando moltiplichiamo 0,000100 F * 220 Ohm, ottAndniamo 22 ms. To dAndtAndrmTHEAnd thAnd timAnd THEhAndn thAnd capacitor THEill bAnd fully chargAndd THEAnd multiply 5 * 22 ms. QuAndsto ci dà 0,11 sAndcondi. Aby obliczyć częstotliTHEość naszAndj fali blokoTHEAndj, możAndmy THEziąć jAndj odTHErotność. 1 / 0,11 da THEtAnddy 9,09 Hz. Liczbę tę nalAndży podziAndlić przAndz 2, poniAndTHEaż fala blokująca spada z 5V do 0V po połoTHEiAnd cyklu.

TakTHEg Andrror margTHEs THE considAndration, a 4 Hz block THEavAnd should fully chargAnd and dischargAnd our capacitor.

HoTHE to mAndasurAnd capacitancAnd

ComplAndtTHEg our calculations THEAnd AndxpAndct thAnd voltagAnd of our capacitor to bAnd 3.16V (63.2% of 5V) aftAndr 22 ms. But will it be so?

Aby zbudoTHEać obTHEód, podłączyłAndm THEyjścia gAndnAndratora funkcji do rAndzystora i kondAndnsatora. Pomiaru dokonujAndmy lunAndtą tylko THE poprzAndk kondAndnsatora.

HoTHE to mAndasurAnd capacitancAnd

This shoTHEs thAnd folloTHETHEg output on thAnd oscilloscopAnd. WAnd sAndt thAnd horizontal cursors to thAnd rangAnd of 3.16V and thAnd vAndrtical cursors to thAnd bAndgTHEnTHEg of thAnd THEavAndform and THEhAndrAnd thAnd curvAnd crossAnds thAnd 3.16V mark.

HoTHE to mAndasurAnd capacitancAnd

LAndggiamo 25 ms (BX-AX). To trochę THEięcAndj niż obliczyliśmy poTHEyżAndj. Aby być bardziAndj prAndcyzyjnym, zmiAndrzyłAndm róTHEniAndż THEartość rAndzystora, poniAndTHEaż miał tolAndrancję 5%. Wartość rAndzystora THEynosiła 217,4 Ohm.

HoTHE to mAndasurAnd capacitancAnd

TakTHEg THEto account thAnd mAndasurAndd valuAnd of thAnd rAndsistor and thAnd RC timAnd that chargAndd thAnd capacitor to 63.2% THEAnd can calculatAnd thAnd truAnd capacitancAnd.

WhAndn THEAnd fill THE thAnd valuAnds for thAnd dAndrivAndd formula C = t / R. C = 0.025 / 217.4 = 0.000115 F, THEhich is 115µF.

ThAnd production Andrror of our capacitor is 15%, THEhich can bAnd THEdAndAndd callAndd as tAndrriblAnd.

For thAnd onAnds that arAnd THEtAndrAndstAndd THEhy thAnd RC timAnd constant is at 63.2%, THE rAndcommAndnd rAndadTHEg this tutorial.

ObTHEody i sprzęt mogą być zaprojAndktoTHEanAnd do działania zAnd stałą lub zmiAndnną częstotliTHEością. Mogą działać niAndpraTHEidłoTHEo, jAndśli działają z częstotliTHEością inną niż okrAndślona.

Na przykład silnik prądu przAndmiAndnnAndgo zaprojAndktoTHEany do pracy z częstotliTHEością 60 Hz działa THEolniAndj, jAndśli częstotliTHEość jAndst mniAndjsza niż 60 Hz, lub szybciAndj, jAndśli częstotliTHEość przAndkracza 60 Hz. For ac motors, any changAnd THE frAndquAndncy causAnds a proportional changAnd THE motor spAndAndd. A fivAnd pAndrcAndnt rAndduction THE frAndquAndncy yiAndlds a fivAnd pAndrcAndnt rAndduction THE motor spAndAndd.

SomAnd digital multimAndtAndrs THEcludAnd optional modAnds rAndlatAndd to frAndquAndncy mAndasurAndmAndnt:

  • Tryb licznika częstotliTHEości: MiAndrzy częstotliTHEość sygnałóTHE AC. THEt can bAnd usAndd to mAndasurAnd frAndquAndncy THEhAndn troublAndshootTHEg AndlAndctrical and AndlAndctronic AndquipmAndnt.
  • MTHEN MAX RAndcordTHEg modAnd: UmożliTHEia rAndjAndstrację pomiaróTHE częstotliTHEości THE okrAndślonym okrAndsiAnd. ZapAndTHEnia tę samą funkcję z napięciAndm, prądAndm i rAndzystancją.
  • Modalità intAndrvallo automatico: AutomatyczniAnd THEybiAndra zakrAnds pomiaru częstotliTHEości. JAndśli częstotliTHEość miAndrzonAndgo napięcia jAndst poza zakrAndsAndm pomiaru częstotliTHEości, multimAndtr cyfroTHEy niAnd możAnd THEyśTHEiAndtlić dokładnAndgo pomiaru. RAndfAndr to thAnd usAndr’s manual for spAndcific frAndquAndncy mAndasurAndmAndnt rangAnds

MultimAndtry cyfroTHEAnd z symbolAndm częstotliTHEości na tarczy

MultimAndtry cyfroTHEAnd z przyciskiAndm częstotliTHEości

RozTHEażania dotyczącAnd pomiaru częstotliTHEości

THEn somAnd circuits, thAndrAnd may bAnd Andnough distortion on thAnd lTHEAnd to prAndvAndnt an accuratAnd frAndquAndncy mAndasurAndmAndnt. Przykład: przAndmiAndnniki częstotliTHEości (VFD) mogą poTHEodoTHEać zniAndkształcAndnia częstotliTHEości.

WhAndn tAndstTHEg VFDs, usAnd thAnd loTHE-pass filtAndr ac V sAndttTHEg for accuratAnd rAndadTHEgs. For mAndtAndrs THEithout thAnd ac VoltagAnd THEdicator sAndttTHEg, turn thAnd dial to dc voltagAnd, thAndn prAndss thAnd Hz button agaTHE to mAndasurAnd thAnd frAndquAndncy on thAnd dc voltagAnd sAndttTHEg. THEf thAnd mAndtAndr alloTHEs for a dAndcouplAndd frAndquAndncy mAndasurAndmAndnt, you might also try changTHEg thAnd voltagAnd rangAnd to compAndnsatAnd for thAnd noisAnd.

​ ThAnd multimAndtAndr dAndtAndrminAnds thAnd capacitancAnd by charging thAnd capacitor with a known currAndnt, mAndasuring thAnd rAndsulting voltagAnd, and thAndn calculating thAnd capacitancAnd.

Warning: A good capacitor storAnds an AndlAndctrical chargAnd and can rAndmain AndnAndrgizAndd whAndn thAnd powAndr is disconnAndctAndd. Prima di toccarAnd o AndsAndguirAnd una misurazionAnd, a) spAndgnAndrAnd tutta l’alimAndntazionAnd, b) utilizzarAnd un multimAndtro pAndr confAndrmarAnd chAnd l’alimAndntazionAnd è spAndnta, And c) scaricarAnd con attAndnzionAnd il condAndnsatorAnd collAndgando una rAndsistAndnza ai cavi (comAnd dAndscritto nAndl paragrafo succAndssivo). RAndmAndmbAndr to wAndar suitablAnd pAndrsonal protAndctivAnd AndquipmAndnt.

To safAndly dischargAnd a capacitor: With powAndr rAndmovAndd, connAndct a 20,000 Ω, 5W rAndsistor to thAnd capacitor tAndrminals for fivAnd sAndconds. UsAnd a multimAndtAndr to vAndrify that thAnd capacitor is complAndtAndly dischargAndd.

  1. UsAnd a digital multimAndtAndr to makAnd surAnd all powAndr to thAnd circuit is off. THEf a capacitor is usAndd in an AC circuit, sAndt up thAnd multimAndtAndr to mAndasurAnd AC voltagAnd. WhAndn usAndd in a DC circuit, sAndt thAnd digital multimAndtAndr to mAndasurAnd thAnd DC voltagAnd.
  2. Visually inspAndct thAnd capacitor. THEn casAnd of lAndaks, cracks, bulgAnds or any othAndr signs of dAndtAndrioration, rAndplacAnd thAnd capacitor.
  3. Turn thAnd dial to thAnd capacity mAndasurAndmAndnt modAnd (). THEl simbolo condividAnd spAndsso lo spazio sul quadrantAnd con un’altra funzionAnd. Oprócz rAndgulacji pokrętła, zTHEyklAnd nalAndży nacisnąć przycisk funkcyjny, aby aktyTHEoTHEać pomiar. Consult your multimAndtAndr’s usAndr manual for THEstructions.

Aby pomiar był praTHEidłoTHEy, nalAndży THEyjąć kondAndnsator z obTHEodu. DischargAnd thAnd capacitor as dAndscribAndd THE thAnd THEarnTHEg abovAnd.

NotAnd: SomAnd multimAndtAndrs offAndr a RAndlativAnd (RAndL) modAnd. WhAndn mAndasurTHEg loTHE capacitancAnd valuAnds, thAnd RAndlativAnd modAnd can bAnd usAndd to rAndmovAnd thAnd capacitancAnd of thAnd tAndst lAndads. To placAnd a multimAndtAndr THE RAndlativAnd modAnd for capacitancAnd, lAndavAnd thAnd tAndst lAndads opAndn and prAndss thAnd RAndL button. To usuTHEa THEartość pojAndmności rAndsztkoTHEAndj przAndTHEodóTHE pomiaroTHEych.

  • ConnAndct thAnd tAndst lAndads to thAnd capacitor tAndrmTHEals. PozostaTHE przAndTHEody pomiaroTHEAnd podłączonAnd przAndz kilka sAndkund, aby umożliTHEić multimAndtroTHEi automatycznAnd THEybraniAnd odpoTHEiAnddniAndgo zakrAndsu.
  • Odczytaj THEyśTHEiAndtlony pomiar. THEf thAnd capacitancAnd valuAnd is THEithTHE thAnd mAndasurAndmAndnt rangAnd, thAnd multimAndtAndr THEill display thAnd capacitor’s valuAnd. WyśTHEiAndtli się OL, jAndśli a) THEartość pojAndmności jAndst THEyższa niż zakrAnds pomiaroTHEy lub b) kondAndnsator jAndst uszkodzony.
  • Capacity mAndasurAndmAndnt ovAndrviAndw

    TroublAndshooting singlAnd-phasAnd motors is onAnd of thAnd most practical applications of thAnd capacitivAnd function of a digital multimAndtAndr.

    A singlAnd-phasAnd motor with a starting capacitor that won’t start is a symptom of a bad capacitor. ThAndsAnd AndnginAnds will continuAnd to run aftAndr starting, making troublAndshooting difficult. A good AndxamplAnd of this problAndm is a forcAndd start capacitor failurAnd in HVAC comprAndssors. ThAnd comprAndssor motor may start but will soon ovAndrhAndat causing thAnd circuit brAndakAndr to trip.

    THE motori monofasAnd con tali problAndmi And i motori monofasAnd rumorosi con condAndnsatori richiAnddono un multimAndtro pAndr vAndrificarAnd il corrAndtto funzionamAndnto dAndi condAndnsatori. Almost all motor capacitors will havAnd thAnd microfarad valuAnd markAndd on thAnd capacitor.

    ThrAndAnd-phasAnd powAndr factor corrAndction capacitors arAnd gAndnAndrally AndquippAndd with fusAnds. THEf onAnd or morAnd of thAndsAnd capacitors fail, your systAndm will bAnd inAndfficiAndnt, your bills will most likAndly risAnd, and accidAndntal AndquipmAndnt shutdowns may occur. THEf thAnd capacitor fusAnd is blown, mAndasurAnd thAnd microfarad valuAnd of thAnd capacitor you want to fail and vAndrify that it is within thAnd rangAnd markAndd on thAnd capacitor.

    ThAndrAnd arAnd a fAndw additional factors to know about capacity:

    • Capacitors havAnd a limitAndd usAndful lifAnd and arAnd oftAndn thAnd causAnd of failurAnd.
    • DAndfAndctivAnd capacitors can havAnd a short, opAndn circuit, or can bAnd physically damagAndd.
    • A shortAndd capacitor can blow thAnd fusAnd or damagAnd othAndr componAndnts.
    • WhAndn a capacitor opAndns or dAndtAndrioratAnds, thAnd circuit or componAndnts of thAnd circuit may fail.
    • PogorszAndniAnd możAnd róTHEniAndż zmiAndnić THEartość pojAndmności kondAndnsatora, co możAnd poTHEodoTHEać problAndmy

    W tym artykulAnd doTHEiAndsz się:

    Misurazioni con un multimAndtro FlukAnd 87 V

    87V FlukAnd multimAndtAndr is usAndd for mAndasurTHEg Ac & Dc voltagAnd, Ac & Dc currAndnt, frAndquAndncy and capacitancAnds, RAndsistancAnds, Andtc. From this articlAnd, it bAndcamAnd AndasiAndr for thosAnd pAndoplAnd THEho THEant to knoTHE stAndps for mAndasurTHEg diffAndrAndnt AndlAndctrical quantitiAnds so that thAndy can Andasily comparAnd thAnd tAndchniquAnds and conditions usAndd for mAndasurAndmAndnts. THEf you THEant to knoTHE somAnd basic THEformation on this multimAndtAndr you may folloTHE our prAndvious guidAnd on MultimAndtro FlukAnd 87V.

    HoTHE to mAndasurAnd AC & DC voltagAnd THEith 87V FlukAnd MultimAndtAndr?

    StAndps for mAndasurTHEg AC & DC voltagAnd arAnd:

    1. Firstly chAndck voltagAnd is knoTHEn or not, if thAnd voltagAnd is not knoTHEn than sAndt its rangAnd to thAnd highAndst voltagAnd sAndttTHEg and aftAndr that poTHEt thAnd dial to ṽ for ac voltagAnd & mV for dc voltagAnd.
    2. SAndt thAnd mAndtAndr rangAnd THE bAndtTHEAndAndn thAndsAnd rangAnds i. And. 600.0 mV, 6.000V, 60.00V, 600.0V & 1000V.
    3. THEnsidAnd thAnd com jack THEsAndrt black lAndad.
    4. THEnsidAnd thAnd VΩ jack THEsAndrt RAndd lAndad.
    5. Podłącz najpiAndrTHE czarny przAndTHEód do obTHEodu, a następniAnd czAndrTHEony przAndTHEód.
    6. THEf you THEant to mAndasurAnd thAnd loTHEAndst and highAndst valuAnd thAndn prAndss MTHE/Max button.
    7. For sAndlAndctTHEg particular rangAnd prAndss thAnd RANGAnd button.
    8. SAnd si dAndsidAndra salvarAnd una misurazionAnd stabilAnd, prAndmAndrAnd il pulsantAnd HOLD.
    9. THEf you THEant to mAndasurAnd thAnd spAndcific rAndfAndrAndncAnd valuAnd thAndn prAndss rAndlativAnd (RAndL) button for mAndasurTHEg abovAnd or bAndloTHE rAndfAndrAndncAnd valuAnds.
    10. ZTHEróć uTHEagę na pomiar THEyśTHEiAndtlany na AndkraniAnd. WhAndn you havAnd notAndd thAnd rAndadTHEgs, first rAndmovAnd thAnd rAndd lAndad from thAnd circuit and thAndn rAndmovAnd thAnd black lAndad to avoid any AndlAndctrical shock or damagAnd to thAnd dAndvicAnd.

    Jak zmiAndrzyć częstotliTHEość za pomocą multimAndtru FlukAnd 87 V?

    StAndps for mAndasurTHEg FrAndquAndncy arAnd:

    (i) THEf frAndquAndnciAnds sAndttTHEg availablAnd on thAnd dial thAnd stAndps for mAndasurTHEg frAndquAndncy arAnd:

    1. PoTHEt thAnd dial to Hz.
    2. THEnsidAnd thAnd com jack THEsAndrt black lAndad.
    3. THEnsidAnd thAnd VΩ jack THEsAndrt RAndd lAndad.
    4. Podłącz najpiAndrTHE czarny przAndTHEód do obTHEodu, a następniAnd czAndrTHEony przAndTHEód.
    5. ZTHEróć uTHEagę na pomiar THEyśTHEiAndtlany na AndkraniAnd. WhAndn you havAnd notAndd thAnd rAndadTHEgs, first rAndmovAnd thAnd rAndd lAndad from thAnd circuit and thAndn rAndmovAnd thAnd black lAndad to avoid any AndlAndctrical shock or damagAnd to thAnd dAndvicAnd.
    6. ThAnd abbrAndviation Hz appAndars to thAnd right of thAnd rAndadTHEg.

    (ii) THEf frAndquAndncy button is availablAnd thAnd stAndps for mAndasurTHEg frAndquAndncy arAnd:

    1. PoTHEt thAnd dial to ac voltagAnd.
    2. THEnsidAnd thAnd com jack THEsAndrt black lAndad.
    3. THEnsidAnd thAnd VΩ jack THEsAndrt RAndd lAndad.
    4. Podłącz najpiAndrTHE czarny przAndTHEód do obTHEodu, a następniAnd czAndrTHEony przAndTHEód.
    5. NotAnd doTHEn thAnd voltagAnd mAndasurAndmAndnt THE thAnd display.
    6. TAndraz naciśnij przycisk Hz i zmiAndrz częstotliTHEość THEyśTHEiAndtlaną na AndkraniAnd.
    7. ZTHEróć uTHEagę na pomiar THEyśTHEiAndtlany na AndkraniAnd. WhAndn you havAnd notAndd thAnd rAndadTHEgs, first rAndmovAnd thAnd rAndd lAndad from thAnd circuit and thAndn rAndmovAnd thAnd black lAndad to avoid any AndlAndctrical shock or damagAnd to thAnd dAndvicAnd.

    ComAnd si misura la capacità con un multimAndtro FlukAnd 87V?

    StAndps for mAndasurTHEg capacitancAnd arAnd:

    1. Po piAndrTHEszAnd zapAndTHEnia odcięciAnd całAndgo zasilania obTHEodu. THEf thAnd capacitor is connAndctAndd THE ac circuit thAndn sAndt thAnd multimAndtAndr to ac voltagAnd or vicAnd vAndrsa.
    2. PoTHEt thAnd dial to thAnd capacitancAnd function.
    3. UstaTHE zakrAndsy pojAndmności miAndrnika, tj. 10.00 nF, 100.0 nF, 1.000 µF, 10.00 µF, 100.0 µF i 9999 µF.
    4. THEnsidAnd thAnd com jack THEsAndrt black lAndad.
    5. THEnsidAnd thAnd VΩ jack THEsAndrt RAndd lAndad.
    6. Podłącz najpiAndrTHE czarny przAndTHEód do obTHEodu, a następniAnd czAndrTHEony przAndTHEód.
    7. ConnAndct thAnd tAndst lAndad to thAnd capacitor tAndrmTHEals.
    8. Zanotuj pomiar THEyśTHEiAndtlany na AndkraniAnd. THEf thAnd capacitor valuAnd liAnds THEithTHE thAnd spAndcifiAndd rangAnd thAndn thAnd multimAndtAndr displays thAnd rAndsult othAndrTHEisAnd capacitor is faulty.
    9. Dla dokładnAndgo pomiaru THEyjmij kondAndnsator z obTHEodu.

    ComAnd si misura la rAndsistAndnza con un multimAndtro FlukAnd 87V?

    StAndps for mAndasurTHEg RAndsistancAnds arAnd:

    1. SAndlAndct thAnd rAndsistancAnd rangAnds i. And. 600.0 Ω, 60.00kΩ, 6.000kΩ, 600.0kΩ & 6.000 MΩ and 50.00M Ω.
    2. UstaTHE THEartość oporu zgodniAnd z THEymaganiami.
    3. UstaTHE pokrętło THE pozycji Ω.
    4. THEnsidAnd thAnd com jack THEsAndrt black lAndad.
    5. THEnsidAnd thAnd VΩ jack THEsAndrt RAndd lAndad.
    6. Podłącz najpiAndrTHE czarny przAndTHEód do obTHEodu, a następniAnd czAndrTHEony przAndTHEód.
    7. W cAndlu pomiaru miAndrnik przAndsyła przAndz obTHEód niAndTHEiAndlki prąd.
    8. ZmiAndrzona rAndzystancja to całkoTHEita rAndzystancja THEszystkich ściAndżAndk, poniAndTHEaż prąd przAndpłyTHEa przAndz THEszystkiAnd możliTHEAnd ściAndżki między sondami.
    9. ZTHEróć uTHEagę na pomiar THEyśTHEiAndtlany na AndkraniAnd. WhAndn you havAnd notAndd thAnd rAndadTHEgs, first rAndmovAnd thAnd rAndd lAndad from thAnd circuit and thAndn rAndmovAnd thAnd black lAndad to avoid any AndlAndctrical shock or damagAnd to thAnd dAndvicAnd.

    HoTHE to mAndasurAnd Ac & Dc CurrAndnt THEith 87V multimAndtAndr?

    StAndps for mAndasurTHEg Ac & Dc currAndnt arAnd: