Ama-multimeters omsebenzi we-Electronics

Ngakho udinga multimeter. Mhlawumbe endala yakho ishonile, mhlawumbe usanda kungena ekulungiseni izinto zikagesi, noma mhlawumbe ukhathele ukuboleka i-Fluke yozakwenu njalo lapho udinga ukuhlola amandla kagesi. Noma ngabe yisiphi isizathu, ukukhetha imitha elungile akuqondile njengoba i-YouTube ikwenza kubukeke.

Sekuyiminyaka engaba ngu-8 ngilungisa izinto zikagesi, ikakhulukazi izinto ezithengwayo kanye nemishini ethile yezimboni, futhi ngidlule cishe kumamitha ayi-6 noma angu-7 ahlukene. Ezinye zaziwudoti, ezinye zazilungile, futhi enye yayiyinhle ngempela ngaze ngayilahla esitebhisini (iphutha lami, hhayi elemitha).

Abaningi abasaqalayo bacabanga ukuthi badinga ukusebenzisa u-$400 kuFluke 87V ngaso leso sikhathi. Lokho akulona iqiniso kubantu abaningi. Ungangizwa kabi-I-Fluke yenza amamitha amahle kakhulu, futhi uma wenza umsebenzi wochwepheshe we-HVAC noma ukunakekelwa kwemboni lapho ukufunda okungalungile kungabiza izinkulungwane ngesikhathi sokuphumula, yebo, thola i-Fluke. Kodwa ngabathanda izinto zokuzilibazisa ze-elekthronikhi noma ngisho nomsebenzi omncane wochwepheshe? Kukhona indawo enkulu emaphakathi.

Okwamanje ngisebenzisa i-Brymen BM869s njengemitha yami eyinhloko. Ibiza cishe u-$180-200 kuye ngokuthi uyithenga kuphi. Inokulungiswa kokubala okungu-60,000 okuzwakala sengathi umbhedo wokumaketha kodwa empeleni kwenza umehluko uma uzama ukubona izinguquko ezincane ku-voltage noma zamanje. Ukufunda kubuyekezwa ngokushesha-cishe izikhathi ezingu-50 ngesekhondi ngokuya ngezicaciso zakhona-okubaluleke kakhulu kunalokho engangikucabanga ngaphambi kokuba ngithole imitha enesampula esheshayo. Uma uphenya ibhodi lesifunda uzama ukuthola inkinga, leyo mpendulo esheshayo ikusiza ukuthi ubone izinkinga ngokushesha.

Ngaphambi kwe-Brymen, ngangine-UNI-T UT61E cishe iminyaka emi-3. Ikhokhelwe mhlawumbe u- $65 ngayo e-Amazon ngo-2019 (izintengo zikhuphuke kusukela lapho, zifana nama- $ 80-90 manje). Leyo mitha yayanele ngokuphelele ku-90% walokho engikwenzile. Okuwukuphela kwesizathu engisenze ngathuthukisa kwakungoba ngaqala ukwenza umsebenzi omningi wokuxilonga izimoto futhi ngidinga isilinganiso esisheshayo samasampula namandla angcono okulinganisa i-AC.

multimeter

Wonke umuntu ukhuluma "ngokunemba" kodwa abantu abaningi abazi nokuthi incazelo yokunemba isho ukuthini. Uma imitha ithi "±0.5% + 3 amadijithi" leyo akuyona nje inombolo eyodwa{3}}kuyimithombo yephutha emibili ehlanganisiwe. Ingxenye yephesenti isekelwe kunani lokufunda, futhi ingxenye yamadijithi iyi-offset engashintshi. Ngakho-ke uma ukala i-10.00V ngaleyo speci, i-voltage yakho yangempela ingaba noma yikuphi ukusuka ku-9.92V kuya ku-10.08V. Ngokuxazulula izinkinga eziningi zikagesi, lokhu akunandaba nhlobo. Ufuna ama-rails angu-5V awehlele ku-4.3V ngenxa ye-capacitor embi, ungazami ukulinganisa izinsimbi ezinembayo.

Lapho ukunemba kubaluleke khona: uma wenza umsebenzi we-analog onembayo, ukulinganisa kwenzwa, noma ukuhlola izinsiza zamandla ukuze uthole izicaciso ze-ripple. Bese yebo, ufuna okuthile okungcono kunokunemba kwe-DC okuyisisekelo okungu-±0.5%. I-Brymen yami ingu-±0.03% okuyi-overkill yezidingo zami, kodwa ifike nephakheji.

Ukulinganisa kwamanje kulapho amamitha ashibhile akhombisa khona ukulinganiselwa kwawo. I-voltage yomthwalo-ukwehla kwamandla kagesi phakathi kwemitha ye-shunt resistor yangaphakathi{2}}ingaba phezulu ngokwanele kumamitha ashibhile kangangokuthi ithinta isekethe oyikalayo. Ngihlole imitha yami endala engu-$20 (angikwazi ngisho nokukhumbula uhlobo) futhi yayinevolthi yomthwalo engu-0.8V ebangeni elingu-10A. Kubi lokho. I-UNI{9}T yayicishe ibe ngu-0.3V. I-Brymen ingaphansi kwe-0.1V. Uma ukala imanje kumjikelezo we-5V, lowo mehluko ubalulekile.

Umbono ongathandwayo mhlawumbe, kodwa empeleni ngithanda ukuhlukahluka kwemisebenzi eminingi. Amamitha we-autoranging afanelekile uma ungazi ukuthi iyiphi i-voltage oyibukayo, kodwa uma ngisebenza ebhodini lapho ngazi khona wonke ama-rails (3.3V, 5V, 12V, noma yini), ngivele ngisethe ububanzi kanye futhi ngiwushiye lapho. Ukushintsha phakathi kwe-auto kanye ne-manual kufanele kube lula nakuba{5}}amanye amamitha ekwenza uhlole amamenyu acasulayo.

I-Fluke 115 (ingaba ngu-$200-}220) cishe iyimitha "yeprosumer" edume kakhulu ngaphandle futhi ngesizathu esihle. Ngokuyisisekelo ayinakuchithwa, inekhwalithi enhle yokwakha, futhi yonke i-interface imane nje... inengqondo. Yonke into ilapho ulindele ukuthi ibe khona. Ngaboleka eyodwa izinyanga ezimbalwa futhi ngokweqiniso isizathu esisodwa sokuthi ngingayithengi kwakungoba ngangifuna izici ezengeziwe uBrymen ayenazo. Uma nje udinga i-voltage, yamanje, ukumelana, ukuqhubeka, nokuhlolwa kwe-diode, i-115 ikwenza kahle konke lokho. Ukwesekwa kwabo kwewaranti nakho kuhle ngokusemthethweni-ngizwile izindaba eziningi ezivela kochwepheshe bezogesi abafake uFluke esikhundleni samamitha ahlulekile ngemva kweminyaka yokuhlukunyezwa.

Yilapho engizozwakala khona ngishumayela kodwa noma yini. Isilinganiso se-CAT kumitha yakho akukhona nje ukumaketha. I-CAT II ilungele umsebenzi we-electronics kanye nomsebenzi we-voltage ephansi. I-CAT III eyamaphaneli okusabalalisa kanye nokufakwa okungaguquki. I-CAT IV ingeyezinga lezinto ezisetshenziswayo. Isilinganiso sikagesi (njenge-600V noma i-1000V) sihlanganiswa nesilinganiso se-CAT ukuze sikutshele ukuthi imitha ingaphatha ini ngokuphephile ngokuya ngesikhashana kanye nezimo zamaphutha.

Amamitha amaningi ashibhile anezilinganiso zokuphepha ezingelona iqiniso noma ezidukisayo. Kube khona impikiswano mayelana nalokhu eminyakeni embalwa edlule-I-EEVblog yabhidliza amanye amamitha ashibhile e-Amazon ayefuna i-CAT III 1000V kodwa yaba nezimvume ezingeke zifanelekele ngisho ne-CAT II. Ividiyo ethile yayimayelana nemitha yenkampani ebizwa ngokuthi "AstroAI" ngicabanga ukuthi, futhi u-Dave Jones wakala ukucaciswa kwe-PCB njengo-2mm lapho kwakudingeka kube ngu-8mm noma okuthile ngesilinganiso abasifunayo. (Umthombo: eevblog.com).

Uma usebenza kuphela ngezinto ezisezingeni eliphansi ze-DC (ngaphansi kuka-48V), lokhu akunandaba ngempela. Kodwa uma wenza noma yimuphi umsebenzi kagesi wamapayipi amakhulu, thenga imitha kumkhiqizo owaziwayo onezitifiketi ezisemthethweni zokuphepha. Lokhu kusho i-Fluke, i-Brymen, i-Keysight, i-Klein, i-Amprobe, noma okufanayo. Akuwona amabhrendi we-Amazon angahleliwe anokubuyekezwa kwezinkanyezi ezi-5 okungasolisi nhlobo.

I-continuity beeper cishe iwumsebenzi-osetshenziswa kakhulu kunoma iyiphi i-multimeter uma wenza umsebenzi wokulungisa. Ukuhlola izikhindi, ukuhlola ukuxhumana, ukulandelela imikhondo ye-PCB{2}}uyisebenzisa njalo. Amanye amamitha anokubambezeleka ngaphambi kokucupha ibhiphu okwenza isici sicishe singabi namsebenzi. Ukubambezeleka kufanele kube ngaphansi kuka-50ms. Noma yini ende futhi uhambisa ama-probe nxazonke uzibuza ukuthi kukhona yini ukuqhubeka noma imitha ayikakhiphi okwamanje.

Imitha yami endala engekho{0}yegama mhlawumbe ibe nokubambezeleka okungu-200-300ms. Udoti ophelele wokuhlola ukuqhubeka okusheshayo. I-UNI{8}T ibingcono kakhulu, cishe cishe ku-30-40ms. I-Brymen empeleni iyashesha. Ngokufanayo namaFlukes engiwasebenzisile-impendulo yawo eqhubekayo yinhle kakhulu.

Amanye amamitha nawo ahlaba emngceleni ophakeme kakhulu. Ukuqhubeka akufani nokumelana okuphansi-okungcono ufuna ukuthi ibhiphu icule entweni efana no-20-50Ω noma ngaphansi. Ngisebenzise amamitha abhiphu afinyelela ku-200Ω ahlula injongo lapho uzama ukuhlukanisa phakathi koxhumano oluhle nolusemaphethelweni.

multimeter

Wonke umuntu ugxila ku-specs yokulinganisa futhi alinaki iqiniso lokuthi kufanele usebenzise into ngempela. Ikhwalithi yesikrini ibalulekile. I-Backlight ibalulekile. Isakhiwo sezinkinobho sibalulekile. Ukuthi ama-lead ahlala kumajekhi abalulekile yini (ngibheke wena, i-Mastech MS8268-labo jakhi babemabi).

I-Brymen inokuboniswa okuhle ngempela-amadijithi amhlophe kungemuva elimnyama, ifundeka kalula kunoma yikuphi ukukhanya. I-backlight ikhanya ngokwanele ukuthi ingasetshenziswa ezimeni ezimnyama kodwa ayikhanyi kakhulu kangangokuthi ilimaza ukubona kwakho ebusuku uma usebenza endaweni emnyama. Imininingwane emincane, kepha iyaziswa.

Ukugcinwa komthofu kungenye into okungekho muntu okhuluma ngayo. Uma usuqedile uwabeka kuphi imikhondo? Amanye amamitha anezibambi ezakhelwe ngaphakathi, ezinye azinazo. Ngisebenzisa izibambi zokuhola kazibuthe ezinamathele ebhokisini lami lamathuluzi elisebenza kahle, kodwa kungenye into ongacabanga ngayo.

Oh kanti nakhu okuthile okungicasulayo: amamitha angenayo i-fuse ehlukile yobubanzi be-mA kanye nobubanzi obungu-10A. Uma ufutha i-fuse eyinhloko, ulahlekelwa yizinhlobo zombili. Amamitha angcono anamafuse amabili ahlukene ukuze ukwazi ukukala amaza aphezulu uma ifuse ye-mA ivunguza. I-Brymen inalokhu, amamitha ashibhile amaningi awanawo.

Amamitha amaningi akhangisa ukukalwa kwezinga lokushisa njengesici. Nge-Brymen uthola K-uhlobo lwe-thermocouple olufakiwe. Ngike ngayisebenzisa mhlawumbe... izikhathi ezinhlanu? Eminyakeni emithathu? Akukhona ukuthi ayisebenzi, ukuthi emisebenzini eminingi yokulinganisa izinga lokushisa, i-thermometer ye-infrared noma imitha ye-thermocouple ezinikele ingcono. Ukunemba komsebenzi wokushisa we-multimeter ngokuvamile into efana ne-±1-2℃elungele ukuhlolwa okungalungile kodwa hhayi okuhle uma empeleni udinga idatha enembile yokushisa.

Lapho kuwusizo khona: ukuhlola izingxenye zokushisa ebhodini uma usola ukuthi kukhona ukushisa ngokweqile. Ungakwazi ukuhlola i-chip noma isilawuli futhi uthole ukufundwa. Kodwa ngezinga lokushisa le-ambient nanoma yini enye, ngingasebenzisa ithuluzi elihlukile.

Zilungele izinto eziyisisekelo. Ngigcina eyodwa ku-toolkit yami yemoto ukuze ngihlole amandla ebhethri hhayi okunye okuningi. Ukunemba kuyangabazeka, ikhwalithi yokwakha iyangabazeka, futhi nokuphepha kuyangabazeka. Kodwa ngezilinganiso zamandla kagesi e-DC ezilula-ezimweni ezinobungozi obuphansi, ziyasebenza. Ungazithembi kunoma yini ebalulekile futhi ungawasebenzisi ku-voltage yamapayipi.

Ngihlole imitha engahleliwe engu-$18 ukusuka ku-Harbour Freight kanye (imodeli yayifana ne-37772, cishe sebeyishintshile manje) futhi ngiqhathanisa ukufundwa ne-Brymen yami. Kumandla kagesi e-DC ngokuvamile bekungaphakathi kuka-0.1-0.2V okwamukelekayo ukuhlola amabhethri. Ku-voltage ye-AC ibigcwele yonke indawo ka-127V endaweni yokuphuma empeleni eyayingu-121V ngokwemitha yami enhle. Lokho akukhona nje okungalungile, lokho kungaba yingozi uma wenza izinqumo ngokusekelwe kulokho kufundwa.

Ngokokunye ukuhlola okwenziwa onjiniyela kwa-Keysight (keysight.com/blogs), imodi yokwehluleka kumamitha ashibhile ivamise ukuba yinhlekelele lapho ehluleka{1}}kungekho ukuvikelwa kwe-arc, ukuxubha okuncane, kanye nokulandela kwe-PCB okuvele kuhwamuke esikhundleni sokwehluleka ngokuphepha. Ukuhlaziywa kwabo kwe-teardown kubonise ikhwalithi yokwakha yangaphakathi engeke iphumelele noma yisiphi isitifiketi esisemthethweni sokuphepha.

Amanye amamitha manje anoxhumo lwe-Bluetooth noma lwe-USB lokungena kwedatha. Angikutholanga lokhu kuwusizo emsebenzini wami, kodwa ngiyakwazi ukubona izinhlelo zokusebenza lapho kungabaluleka khona-ukuqapha{2}}isikhathi eside, ukuhlola okuzenzakalelayo, lolo hlobo lwento. I-Brymen BM869s ine-USB yokubona (hhayi imodeli efanayo enginayo kodwa abayenzayo) ewusizo ngempela ngoba ukuhlukaniswa ngokubona kusho ukuthi awekho amaluphu aphansi noma izinkinga zomsindo lapho uxhumeka kukhompuyutha.

Uma udinga ukugawulwa kwemithi, kukhona ama-multimeters okugawula anikezelwe aklanyelwe leyo njongo. I-Fluke 289 isibonelo ingagcina izinkulungwane zokufundwayo ngezitembu zesikhathi. Izindleko ezifana ne-$500+ noma kunjalo akuyona into yokuthenga okungahleliwe.

multimeter

Kothile osanda kungena ezintweni zikagesi: UNI-T UT61E noma okufanayo ~$70-80 ububanzi imitha. Ikuthola ukunemba okwanele okwanele kokufunda futhi ngeke ufe uma uphenya ngephutha okuthile okungalungile (inezici zokuphepha eziphusile). Yonga imali ukuze uthole amathuluzi angcono njenge-ayina yokuhlanganisa enhle noma ububanzi.

Ngomsebenzi wochwepheshe wokukhanda ama-electronics: Brymen BM869s noma i-Fluke 115/117. Kokubili cishe ngama- $ 180-220. I-Brymen inezici eziningi, i-Fluke iqinile futhi inokusekelwa okungcono kwewaranti. Akukwazi ukungahambi kahle nakho.

Ngomsebenzi wezimboni/kagesi: Fluke 87V noma okulinganayo. $400-450 kodwa kuwufanele ngezilinganiso zokuphepha nokuqina. Ngeke ngishibhile lapha ngoba imiphumela yokuhluleka kwamamitha mibi kakhulu.

Okwezimoto: Idinga ukunemba okuhle kwe-voltage ye-AC (ngezinzwa), amasampula asheshayo, kanye nesilinganiso somjikelezo we-Hz/duty. IFluke 88V idumile kodwa iyabiza. Kukhona amamitha athile ezimoto-avela ezinkampanini ezifana ne-Snap{4}}kodwa abiza kakhulu futhi cishe awakufanelekeli ngaphandle kokuthi{5}}uwubuchwepheshe besikhathi esigcwele.

Akekho odinga imitha yebhentshi ye-Keysight 34461A ngaphandle uma wenza i-metrology noma umsebenzi wokulinganisa ngokunemba. Lawo aqala ku-$900+ futhi yebo anembe ngendlela emangalisayo (±0.004% DC V) kodwa awasebenzi nhlobo ekulungiseni okuvamile nokuxazulula izinkinga. Lokhu ngikubalula ngoba ngike ngabona abantu ezinkundleni bebancoma kwabaqalayo okuyinto ewubulima nje.

Yilokho okuningi engicabanga ukuthi kubalulekile lapho ukhetha i-multimeter. Ayizange ihlanganise izici zokuhlanganisa i-oscilloscope noma ezinye zezinhlobo zokulinganisa ezikhethekile ngempela (i-inductance, amandla angaphezu kokuhlola okuyisisekelo) ngoba ngokusobala angisebenzisi lezo ezanele ukuze ngibe nemibono eqinile. Thenga okuthile kumkhiqizo osemthethweni onezitifiketi zokuphepha zangempela, qiniseka ukuthi i-continuity beeper iyashesha, futhi cishe uzolunga.

Oh futhi okokugcina{0}}gcina amabhethri ayisipele ekhona. Amamitha amaningi asebenzisa i-9V kodwa amanye amamodeli (ama-Flukes athile, isibonelo) ayawadingaibhethri ye-lithium CR1/3Nokungajwayelekile. Ukufa imitha yakho phakathi nomsebenzi wokulungisa kuyacasula, ngakho-ke vele ubambe izinsimbi ezimbalwa lapho u-oda imitha.