Gwaro reKelvin Connection PCB Layout

Kubatana kweKelvin, kunonziwo kubatana kwewaya ina kana kuti kwemagumo mana, kunoparadzanisa nzira inotakura magetsi kuburikidza nechinhu kubva munzira inonzwa magetsi ari pamusoro payo, kuitira kuti kuramba kwewaya nemajoini e solder kusakanganisa kuyerwa. Ndiyo nzira yakajairika yekuyera kusimba kudiki uye yekuona magetsi ari pamusoro pe shunt ine kukosha kwakaderera. Gwaro iri rinotsanangura kuti kubatana kweKelvin chii, nei kuyerwa kwewaya mbiri kuchikundikana, uye kuti ungaisa sei tsoka ye sense-resistor, kuronga mitsetse ye sense, uye kugadzira bhodhi kuitira kuti kururama kurambe kuripo mukugadzirwa.

Chii chinonzi Kelvin (4-Waya) Connection?

Pfungwa yacho ndeyekupa chinhu chiri kuyerwa mapeya maviri akazvimiririra ekubatanidza pane peya imwe chete yakagovaniswa.

Nzira dzesimba nepfungwa

• The simba nzira inotakura chiyero (kana mutoro) chemagetsi chinopinda nekubuda muchinhu. Chero kuramba kuri munzira iyi kunokonzera kudzikira kwevoltage, asi kudzikira ikoko kunoitika kunze kwenzvimbo yekunzwa.
• The pfungwa Nzira inobatanidza nechinhu ichi kuti ione voltage iri pamusoro payo. Inoendeswa kune high-impedance input kuitira kuti pasave nemagetsi anoyerera mairi, zvinoreva kuti kuramba kwesense wiring hakukonzeri kukanganisa.

Nekuti kubatana kwesense kunobata voltage zvakananga pachinhu uye hakuna magetsi ane revo, chiyero chinoratidza chinhu chacho pachacho, kwete waya nemajoini anotungamira kwachiri. Ndiwo mabhenefiti ese ehunyanzvi.

A zvishoma nhoroondo

Nzira iyi yakatumidzwa zita raIshe Kelvin, ane bhiriji raKelvin remuzana remakore rechi19 rakagadzirwa nemazvo kuti ripime kusimba kwakaderera zvikuru nemazvo. Nheyo imwecheteyo, kupatsanura simba nepfungwa, ndiyo iri pasi pemaseketi emazuva ano ekuona magetsi uye ekuyera nemazvo.

Sei Kuyerwa kweWaya mbiri Kuchikundikana

Kuti uone kuti nei paine waya ina dzinodiwa, tarisa kuti chii chinokanganisa newaya mbiri. Mukuyera kwewaya mbiri, pairi imwe chete yekubatanidza inotakura magetsi uye inonzwa voltage, saka voltage yakayerwa inosanganisira kudonha kwewaya nejoints dzesolder, kwete kungopfuura nepakati pechinhu chete.

Muenzaniso unoshanda

Ngatitii wapfuura 50 A kuburikidza ne 0.5 mΩ shunt kuti upime current. Chiratidzo chinobatsira ndeichi:

50 A × 0.0005 Ω = 25 mV

Zvino funga nezvezvipembenene. Joint inosundwa inogona kuwedzera 0.1–0.2 mΩ zviri nyore, uye matrace anobatanidza anowedzera. Muchirongwa chewaya mbiri, maresistance iwayo anogara akatevedzana neshunt uye anoyerwa pamwe chete nayo. Kunyangwe zvikamu zvishoma zvegumi zve milliohm yejoint netrace resistance, zvichipesana ne 0.5 mΩ shunt, zvinounza kukanganisa kwe20% kana kupfuura, uye inodonha nekupisa sezvo majoint nemhangura zvichidziya. Tafura inoita kuti musiyano uve pachena.

Kubatana kwewaya ina kunobvisa kukanganisa uku nekuti nzira yekunzwisisa inokanganisa voltage pa shunt pachayo uye haina magetsi. Ndosaka kuona magetsi nenzira yechokwadi nguva dzose kunoshandisa Kelvin connection.

Kunoshandiswa Kelvin Connections

Chero kupi zvako panofanira kuyerwa simba diki kana kuti simba remagetsi nemazvo, ndipo panofanira kuonekwa kubatana kweKelvin.

• Kushanda kwesimba remagetsi panguva ino, kesi yekare, inoyera simba remutoro uchishandisa resistor ine mutengo wakaderera.
• Battery manejimendi masisitimu, uko kuteverwa kwakarurama kwezvino uye mamiriro ekushanda kunoenderana nekunzwa kwakachena.
• Madhiraivha emota nema inverter, chikamu chekunzwa kana simba rebhazi rekudzora nekudzivirira.
• Power supplies, yemiganhu iripo, mitemo, uye kutarisa.
• Kuyerwa kwekudzivirira kwakaderera kazhinji, sekureva zvinobatanidza, mawindings, kana contacts.

Mashandisirwo aya anowanzo sanganisira mafungu emvura akakwira uye kupisa kwakanyanya, ndosaka marongerwo uye kugadzirwa kwezvinhu zvese zvichikosha, uye nei kunzwa kwemagetsi kuri dingindira rinodzokororwa mukugadzira magetsi emagetsi.

Kusarudza Shunt Resistor

Usati waisa Kelvin connection, shunt pachayo inofanira kusarudzwa. Zvikamu zvina ndizvo zvinonyanya kukosha pakusarudza izvozvo.

Kukosha kwacho inzira yekuenzanisa. Muenzaniso wakashanda kare, 50 A kusvika 0.5 mΩ ichipa 25 mV, wakanakira amplifier yemagetsi asingashandise simba rakawanda. Sarudza kukosha kwakaderera kuchiri kupa chiratidzo chakachena, simbisa chiyero chesimba ne margin pa peak current, uye sarudza chikamu cheTCR chakaderera kuti chive chakarurama. Mumagadzirirwo emagetsi ane simba rakawanda kupisa kunobviswa neshunt kunogona kuve kwakakosha, saka kunobatanidzwa zvakare mukuronga kwekupisa kumwe chete kunoita kuti sarudzo dzekugadzira magetsi emagetsi dzishande.

Kuisa Rutivi Rwepfungwa Runodzivirira Kunzwa

Kubatana kweKelvin kunoitika kana kuti kunorasika muchimiro. Maitiro mashoma chaiwo akakosha.

Shandisa nzira yakatsaurirwa yekufamba netsoka ine mapad mana

Pane kushandisa nzira isina kurongeka ye2-pad resistor footprint, shandisa nzira ine 4-pad pattern: mahombe maviri ane simba remagetsi anotakura magetsi uye madiki maviri ane sense pads anobata voltage. Mazhinji ma precision shunts anotsanangurwa neKelvin footprint iyi, uye kutevedzera nzira inokurudzirwa nemugadziri ndiyo pokutangira.

Dzvanya chinongedzo chepfungwa pamucheto wechinhu chacho

Batanidza ma sense pads ari mumuviri we resistor, mukati me force connections, kuitira kuti sensed voltage ive pamusoro pe element chete uye haibatanidzi force-pad uye joint resistance. Apo sense taps ndiyo chinhu chinonyanya kukosha: tinya kunze kwe force path wobva waunzazve error chaiyo inobviswa ne technique.

Chengetedza ma "force pads" akaenzana

Ita kuti ma "force pads" maviri aenzane muhukuru uye kubatana kwemhangura. Kusaenzana hakusi dambudziko remagetsi chete, asi idambudziko rekugadzira: mhangura isina kuenzana inokwevera kupisa zvisina kuenzana panguva yekudzoreredza mvura, saka mugumo mumwe wechikamu unopisa wonyorova pamberi peumwe. Kusaenzana ikoko kunogona kusimudza kana kushandura chikamu, kukundikana kwekuva matombo. Ma "force pads" akaenzana, akaenzana, anochengetedza mativi ese ari maviri achidziya zvakaenzana uye chikamu chakaiswa nemazvo, ndipo panobatsira pakugadzira PCB.

Kutungamira Mitsetse Yekunzwisisa

Kana tsoka yacho iri kurudyi, zviratidzo zvepfungwa zvinoda kurongwa zvakanaka kuti zvirambe zvakarurama.

Pfupi, yakaenzana, uye iri kure neyazvino

• Ronga mitsetse miviri yepfungwa semiviri yakatarangana, yakareba zvakafanana, vachizvibata sechiratidzo chekusiyanisa saka ruzha runobatana zvakaenzana uye runodzima.
• Vachengetedze vapfupi uye kuvaendesa kure nenzira yesimba remagetsi ane simba guru uye kubva kumanodhi ekuchinja.
• Vatumire kune inopinzwa ine impedance ine simba guru, amplifier yemagetsi kana ADC, saka kuyerera kwemagetsi kusingakoshi uye kuramba kwemagetsi newaya yemagetsi hazvikonzeri kudzikira.

Kumberi kwekuyera

Iyo sense pair inowanzo batana ne amplifier yemagetsi (midziyo yakaita seINA219 kana INA240 mienzaniso yakajairika) kana zvakananga kune iyo precision ADC input. Kuwedzera madiki, matched series resistors (akaenzana nema ohms mashoma kusvika gumi) mumutsara wega wega we sense kunopa kupinza kwekuisa uye kudzivirira pasina kusawiriranisa iyo peya. Nekuti iyi i analog routing chaiyo pedyo ne high currents, imwe nzira imwechete inoshandiswa mubasa re high-speed uye controlled-impedance , nzira dzekudzoka dzakangwarira uye trace control, inoshandawo pano.

Second-Order Migumisiro

Kana zvinhu zvekutanga zvanyatsojeka, zvimwe zvinhu zvishoma zvinoisa muganho pakururama.

EMF yekupisa (voltage yekupisa)

Kubatana pakati pesimbi dzakasiyana, solder, copper, resistor element, zvinogadzira ma voltage madiki kana paine tembiricha inoyerera pamusoro padzo. Padanho re microvolt, ma thermoelectric EMF aya akakosha pakuyera kwakanyatsojeka. Kuchengeta ma sense junctions ari symmetric uye ari patembiricha dzakafanana, uye kudzivirira nzvimbo dzinopisa dziri pedyo ne sense taps, kunoderedza mhedzisiro.

Kuenzanisa uye kusvetuka

Kuti zvive zvakarurama kwazvo, gadzirisa mubatanidzwa wapera uye tarisa tembiricha ye shunt. Kurongeka kwakanaka kunobvisa zvikanganiso zvakakura; kugadzirisa kunobata zvasara, uye kudzora kupisa kunochengetedza kudzivirira kwe shunt, dzimwe nguva zvinoda substrate yakakodzera kubatanidzwa kwesimbi-core mumagadzirirwo ane simba guru.

Kufunga Kwekugadzira

Dhizaini yaKelvin inotaridzika zvakanaka muCAD ichiri kuenderana nekuti yakavakwa sei. Zvinhu zvakawanda zvinogadzirisa zvakananga mhedzisiro yacho.

• Kurambana kwemajoini anosungirirwa pamwe chete uye kugara kwenguva refu. Kunyange zvazvo nzira yepfungwa ichipfuura majoini esimba, majoini esimba anogara aripo, asingapindi simba zvakanyanya anochengetedza nzira yemazuva ano yakagadzikana; kubatanidzwa kwakadzorwa kunoita kuti pave nekuenderana ikoko.
• Kuenzana kwetsoka mukuita. Mapedhi esimba akaenzana anofanira kuvakwa uye kusungirirwa zvakaenzana kudzivirira kutemwa kwematombo uye kuchinja kwenzvimbo, izvo zvinoenderana nekugadzirwa kwestencil uye kudzokororwa kwemufananidzo.
• Kudzora kurongeka kwetrace nemhangura. Geometry yemhangura yakarurama uye inodzokororwa inoita kuti nzira yesimba uye pfungwa dzakafanana dzirambe dzichiita sezvakagadzirwa, zvichienderana nezviri pasi payo. Pcb kugadzira Unhu.
• Kuedzwa uye kusimbiswa. Kusimbisa chiyero ichi zvichienderana nereferensi inozivikanwa kunosimbisa dhizaini nekuvakwa kwayo, uye mhedzisiro inowirirana pachiyero inobva mukudzora maitiro mu high-volume PCB musangano.

Kunzwisisa matambudziko ekugadzira zvinhu nekukurumidza ndizvo chaizvo zvinorehwa neongororo yeDFM , zvichiratidza kuti shunt footprint, pad balance, uye sense routing zvinogadzirwa usati wazvipira.

Kubatana kweKelvin kuri nyore kunzwisisa, simba rakasiyana kubva kupfungwa, asi kunongopa kururama kwaro kana tsoka, kudhonza kwenzwi, nzira yekufambisa, uye kugadzirwa kwese kuchishanda pamwe chete. Zviite nemazvo uye unogona kuyera mamirioni nemafungu emhepo akakwira nechivimbo. Unogona kuverenga zvakawanda nezveHighleap Electronics uye kugona kwedu kurongeka uye kubatanidza simba.

Mibvunzo Inonyanya Kubvunzwa

Chii chinonzi kubatana kwaKelvin?

Kubatana kwewaya ina (four-terminal) kunoparadzanisa nzira inotakura magetsi kubva panzira inoona magetsi. Nekuti nzira yekunzwisisa inokanganisa voltage pane element uye haina magetsi, kuramba kwewaya uye solder-joints hazvikanganisi kuyerwa, zvichiita kuti pave nekusagona kudzora magetsi uye kunzwa magetsi.

Sei ndisingakwanise kungoshandisa nzira yakajairika yekubatanidza waya mbiri?

Muchirongwa chewaya mbiri, kubatana kumwe chete kunotakura magetsi emagetsi nemagetsi emagetsi, saka kuverenga kunosanganisira madonhwe pakati pemaronda nemajoini emagetsi. Pakurwisa shunt yemazinga emamiriyoni, zvikamu zvishoma zvegumi zve milliohm zvekudzivirira majoini zvinogona kukonzera kukanganisa kwe20% kana kupfuura, uye zvinofamba nekupisa.

Ndinoshandisa kupi mitsetse yepfungwa pa shunt?

Pamuviri chaipo pe resistor, mukati me force connections, saka voltage inonzwika iri pamusoro pe element chete. Kubata kunze kwe force path kunodzoreredza joint ne trace resistance yauri kuedza kubvisa, zvichikanganisa chinangwa cheKelvin connection.

Sei ma "force pads" e "shunt" achifanira kunge akaenzana?

Mhangura isina kuenzana iri pama force pads maviri inokwevera kupisa zvisina kuenzana panguva yekuyerera kwemvura, saka mugumo mumwe unonyorova pamberi peumwe uye chikamu chacho chinogona kusimudzwa kana kusuduruka, zvichikonzera matombo eguva. Ma force pads akaenzana, akaenzana anopisa mativi ese zvakaenzana, zvichiita kuti nzvimbo yacho ive yakarurama uye kubatana kwacho kuve kwakavimbika.

Ndinofanira kutsanangura sei nzira mbiri idzi dzekunzwisisa?

Sechipenga chipfupi, chakataramukana, chakaenzana nehurefu, chakachengetwa kure nenzira yesimba remagetsi ane simba guru uye ma node ekuchinjana, zvichiguma ne high-impedance input senge current-sense amplifier kana ADC. Zvidziviriro zvidiki zve series matched zvinowedzera kusefa nekudzivirira pasina kukanganisa pair yacho.

Ndezvipi zvinhu zvinogadzira zvinhu zvinokanganisa kunyatsoona kwaKelvin?

Majoini esimba anogara aripo, asingapindi simba zvakanyanya; kusungirirwa kwemapedhi esimba zvakaenzana kudzivirira kutemwa nematombo; geometry yemhangura yakarurama uye inodzokororwa yenzira yesimba uye sense pair; uye kusimbiswa zvichienderana nereferensi. Ongororo yeDFM isati yagadzirwa inosimbisa kuti tsoka uye nzira yacho zvinovakwa.

Ndingasarudza sei kukosha kwekudzivirira shunt?

Sarudza kukosha kwakaderera kuchiri kupa chiratidzo icho amplifier yako kana ADC inogona kuverenga zvakachena, izvo zvinoderedza simba rinopera uye mutoro wevoltage. Simbisa kuti simba rinobata I²R pa peak current ine margin, uye sarudza chikamu chine low-temperature-coefficient (TCR) kuitira kuti kuverenga kurambe kwakarurama sezvo shunt ichipisa.