Kusindikizidwa bolodi dera mavuto ovuta ndi mayankho

Q: Monga tanena kale za otsutsa osavuta, payenera kukhala ena otsutsa omwe magwiridwe awo ndizomwe timayembekezera. Kodi chimachitika ndi chiyani kukana kwa gawo la waya?
Y: Zinthu nzosiyana. Mwina mukukamba za waya kapena gulu lotsogola lomwe limasindikizidwa lomwe limakhala ngati waya. Popeza ma superconductors ofunda kutentha sanapezekebe, kutalika kwake kwa waya wachitsulo kumangokhala kosatsutsana (komwe kumagwiranso ntchito ngati capacitor ndi inductor), komanso momwe zimathandizira pakuzungulira.
2. Q: Kukaniza kwa waya waufupi kwambiri wamkuwa m’chiwonetsero chazing’ono sikuyenera kukhala kofunikira?
A: tiyeni tiganizire za 16-bit ADC yokhala ndi vuto la 5k ed. Tangoganizirani kuti mzere wazizindikiro wolowera ku ADC uli ndi bolodi loyenda (0.038mm lakuda, 0.25mm mulifupi) lokhala ndi gulu loyenda la 10cm m’litali. Imatsutsana pafupifupi 0.18 ω kutentha, komwe ndi kochepera kuposa 5K ω × 2 × 2-16 ndipo imapanga cholakwika cha 2LSB pamlingo wathunthu.
Mosakayikira, vutoli limatha kuchepetsedwa ngati, monga ziliri kale, gulu loyendetsa la PRINTED board board likukulitsidwa. M’mabwalo a analog, nthawi zambiri ndimakonda kugwiritsa ntchito gulu lonse, koma opanga ma PCB ambiri (ndi opanga ma PCB) amakonda kugwiritsa ntchito mulingo wocheperako wamagulu kuti athandizire kuyika mzere wazizindikiro. Pomaliza, ndikofunikira kuwerengera kukana kwa gulu lotsogolera ndikuwunika momwe ntchito yake ikuyendera pamavuto onse omwe angakhalepo.
3. Q: Kodi pali vuto ndi kuthekera kwa gulu loyendetsa lokhala ndi m’lifupi kwambiri komanso chitsulo chosanjikiza kumbuyo kwa bolodi la PRINTED?
A: Ndi funso laling’ono. Ngakhale capacitance kuchokera pagulu loyendetsa la PRINTED board board ndikofunikira (ngakhale pama circuits otsika kwambiri, omwe amatha kupanga kukokoloka kwapafupipafupi), ziyenera kuwerengedwa koyamba. Ngati sizili choncho, ngakhale gulu lalikulu lopanga capacitance lalikulu silovuta. Ngati mavuto abuka, gawo laling’ono la ndege yapansi limatha kuchotsedwa kuti lichepetse mphamvu zapadziko lapansi.
Q: Siyani funso ili kwakanthawi! Ndege yoyikira ndi chiyani?
A: Ngati zojambulazo zamkuwa mbali yonse ya PRINTED dera board (kapena interlayer yonse ya multilayer yosindikizidwa board board) imagwiritsidwa ntchito kukhazikika, ndiye izi ndi zomwe timazitcha ndege yokhazikika. Mawaya aliwonse apansi azikonzedwa ndi zing’onozing’ono zotheka kukana ndikuchotsa. Ngati makina agwiritsira ntchito ndege yokwerera pansi, sizingakhudzidwe ndi phokoso lakumtunda. Kuphatikiza apo, ndege yolowera pansi imagwiranso ntchito yoteteza komanso kuzizira
Q: Ndege yoyikira yomwe yatchulidwa pano ndiyovuta kwa opanga, sichoncho?
Y: Panali zovuta zina zaka 20 zapitazo. Lero, chifukwa chakusintha kwa binder, solder kukana ndi ukadaulo wa soldering m’mabodi osindikizidwa, kupanga ndege yokhazikika kwakhala ntchito yayitali yama board osindikizidwa.
Q: Munati kuthekera kowonetsa dongosolo ku phokoso lapansi pogwiritsa ntchito ndege yapansi ndikochepa kwambiri. Kodi ndi zotsalira ziti zavutoli la nthaka zomwe sizingathetsedwe?
A: Dera loyambira la phokoso lokhazikika lili ndi ndege yapansi, koma kulimbikira kwake komanso kusakhazikika kwake sikuli zero – ngati gwero lakunja lakunja ndilolimba, lingakhudze zizindikiritso zenizeni. Vutoli limatha kuchepetsedwa pokonzekera bwino ma board oyenda osunthika kuti magwero apamwamba asayende kupita kumadera omwe amakhudza mphamvu yama voliyumu olondola. Nthawi zina kupuma kapena kudula pakati pa ndege kumatha kupatutsa mphamvu yayikulu kuchokera kumalo ovuta, koma kukakamiza kusintha ndegeyo kumathanso kusunthira chizindikirocho kumalo ovuta, motero njira imeneyi iyenera kugwiritsidwa ntchito mosamala.
Q: Kodi ndingadziwe bwanji kutsika kwamagetsi komwe kumachitika mundege?
A: kawirikawiri kutsika kwamagetsi kumatha kuyezedwa, koma nthawi zina kuwerengera kumatha kutengera kutengera kwa zinthu zomwe zili mundege (dzina limodzi la 1 lamkuwa limakhala lolimba 045m ω / □) ndi kutalika kwa conductive band momwe zimadutsira pakadali pano, ngakhale kuwerengera kumatha kukhala kovuta. Voltages mu DC to low frequency frequency (50kHz) amatha kuyeza ndi zida zamagetsi monga AMP02 kapena AD620.
Kuchulukitsa kwamphamvu kunayikidwa pa 1000 ndikulumikizidwa ndi oscilloscope ndikumverera kwa 5mV / div. Amplifier akhoza kutumizidwa kuchokera kumagwero amagetsi omwewo ngati dera loyesedwa, kapena kuchokera kumagwero ake amagetsi. Komabe, ngati chopukusira pansi chisiyanitsidwa ndi mphamvu yake, oscilloscope iyenera kulumikizidwa ndi mphamvu yamagetsi yamagetsi yogwiritsidwa ntchito.
Kulimbana pakati pa mfundo ziwiri zilizonse pa ndege yapansi kumatha kuwerengedwa powonjezera kafukufuku pamalingaliro awiriwo. Kuphatikiza kwamphamvu yama amplifier ndi chidwi cha oscilloscope kumapangitsa chidwi cha muyeso kufikira 5μV / div. Phokoso lochokera pama amplifier liziwonjezera kukula kwa mawonekedwe a oscilloscope waveform pafupifupi 3μV, komabe nkutheka kukwaniritsa chisankho cha 1μV – chokwanira kusiyanitsa phokoso lapansi kwambiri mpaka chidaliro cha 80%.
Q: Kodi tiyenera kudziwa chiyani panjira yoyesayi?
A: Maginito aliwonse osinthira amathandizira magetsi pazowunikira, zomwe zimatha kuyesedwa ndikuchepetsa ma probes wina ndi mnzake (ndikupereka njira yolowera kutsutsana pansi) ndikuwona mawonekedwe a oscilloscope. Mawonekedwe a AC omwe amawoneka chifukwa chololeza ndipo amatha kuchepetsedwa posintha mawonekedwe a lead kapena poyesa kuthana ndi maginito. Komanso, m’pofunika kuonetsetsa kuti maziko a mkuzamawu ndi olumikizidwa ku maziko a dongosololi. Ngati mkuzamawu uli ndi kulumikizaku kulibe njira yobwerera yopitilira ndipo mkuzamawu sugwira ntchito. Kukhazikitsa pansi kuyeneranso kuwonetsetsa kuti njira yokhazikitsira pansi siyikusokoneza magawidwe apano a dera lomwe likuyesedwa.
Q: Kodi mungayese bwanji phokoso lalitali kwambiri?
Yankho: Zimakhala zovuta kuyeza phokoso la hf pansi ndi chopangira choyenera cha wideband, choncho ma hf ndi ma VHF ma probes ndi oyenera. Amakhala ndi ferrite maginito mphete (wakunja awiri a 6 ~ 8mm) ndi koyilo awiri 6 ~ 10 akutembenukira aliyense. Kuti mupange chosinthira chodzichitira pafupipafupi, koyilo imodzi imalumikizidwa ndi kulowetsa kwa sipekitiramu ndipo inayo ku kafukufuku.
Njira yoyeserayi ndiyofanana ndi kesi yocheperako, koma chowunikira chimagwiritsa ntchito matalikidwe amtundu wa matalikidwe kuyimira phokoso. Mosiyana ndi nthawi yayitali, magwero amawu amatha kusiyanitsidwa mosavuta kutengera mawonekedwe awo pafupipafupi. Kuphatikiza apo, chidwi cha chowunikira cha sipekitiramu ndichoposa 60dB kuposa cha Broadband oscilloscope.
Q: Nanga bwanji kuchepa kwa waya?
A: Kulephera kwa ochititsa ndi magulu a PCB sanganyalanyazidwe pafupipafupi. Kuti muwerenge kulowerera kwa waya wowongoka komanso gulu loyendetsa, kuyerekezera kumodzi kumayambitsidwa pano.
Mwachitsanzo, gulu loyendetsa 1cm kutalika ndi 0.25mm mulifupi limapanga kulowerera kwa 10nH.
Kuchititsa conductor = 0.0002LLN2LR-0.75 μH
Mwachitsanzo, kutulutsa kwa waya wa 1cm kutalika kwa 0.5mm wakunja ndi 7.26nh (2R = 0.5mm, L = 1cm)
Othandizira band inductance = 0.0002LLN2LW + H + 0.2235W + HL + 0.5μH
Mwachitsanzo, kutulutsa kwa 1cm mulifupi 0.25mm kusindikiza komiti yoyenda ndi 9.59nh (H = 0.038mm, W = 0.25mm, L = 1cm).
Komabe, kuyambiranso kocheperako nthawi zambiri kumakhala kocheperako kuposa kuphulika kwa parasitic ndikupangitsa kuti magetsi azizungulira. Malo ozungulirako ayenera kuchepetsedwa chifukwa ma voliyumu oyendetsedwa amafanana ndi malo ozungulira. Izi ndizosavuta kuchita ngati zingwe zopindika.
M’mabwalo osindikizidwa, njira zoyendetsera ndikubwerera ziyenera kukhala zoyandikana. Kusintha kwa zingwe zazing’ono nthawi zambiri kumachepetsa zovuta, onani gwero A kuphatikiza mphamvu yocheperako ya B.
Kuchepetsa malo ozungulira kapena kuwonjezera mtunda pakati pa zolumikizira kumachepetsa zotsatirapo. Malo ozungulira nthawi zambiri amakhala ocheperako ndipo mtunda wapakati pazolumikizira umakulitsidwa. Kuteteza maginito nthawi zina kumafunikira, koma ndiokwera mtengo komanso kosavuta kulephera kwa makina, motero pewani.
11. Q: Mu Q&A ya Ma Injiniya Ofunsira, machitidwe osakhala abwino amamasekeli ophatikizidwa amatchulidwa nthawi zambiri. Ziyenera kukhala zosavuta kugwiritsa ntchito zinthu zosavuta monga zotsutsana. Fotokozani kuyandikira kwa zinthu zabwino.
A: Ndikungofuna kuti resistor ikhale chida choyenera, koma cholembera chaching’ono chotsogola chimatsutsana chimodzimodzi. Chotsutsana chenichenicho chimakhalanso ndi chinthu cholingalira chotsutsa – gawo loyankhira. Ma resistor ambiri amakhala ndi capacitance yaying’ono (makamaka 1 mpaka 3pF) mofananira ndi kukana kwawo. Ngakhale ena amatsutsa amakanema, ma helical groove omwe amawadula m’mafilimu awo otsutsana nawonso samangolowerera, kuyeserera kwawo kumakhala makumi kapena mazana a nahen (nH). Zachidziwikire, kulimbana kwa mabala amtundu wama waya nthawi zambiri kumakhala kopatsa chidwi osati kopepuka (osachepera pafupipafupi). Kupatula apo, makina olumikizira mabala amtundu wa waya amapangidwa ndi ma coil, chifukwa chake sizachilendo kuti ma resistor a waya-mabala amakhala ndi mayikidwe a ma microhm (μH) angapo kapena makumi a microhm, kapena otchedwa “non-inductive” waya-bala resistors (pomwe theka lazitsulo limavulazidwa motsatizana ndi theka lina mosemphana ndi wotchi). Kotero kuti inductance yopangidwa ndi magawo awiri a coil amatha wina ndi mnzake) ilinso ndi 1μH kapena zochulukirapo zotsalira. Pazitsulo zamtengo wapatali zamtundu wa waya zopitilira 10k ω, ma resistor otsala amakhala ndi capacitive m’malo mokhala olimba mtima, ndipo capacitance imakhala mpaka 10pF, yokwera kuposa ya kanema wochepa thupi kapena ma resistor opanga. Izi zimayang’aniridwa bwino popanga ma circuits othamanga omwe amakhala ndi ma resistor.
Q: Koma maseketi ambiri omwe mumafotokoza amagwiritsidwa ntchito poyesa DC kapena mafupipafupi. Othandizira osochera ndi ma capacitors osochera ndiosafunika m’mapulogalamuwa, sichoncho?
A: inde. Chifukwa ma transistors (onse ophatikizika komanso amkati mwa ma circuits ophatikizika) amakhala ndi mulifupi kwambiri band band, oscillations nthawi zina amatha kupezeka m’magulu mazana kapena masauzande amamegahertz pomwe dera limatha ndi katundu wambiri. Zomwe zakonzedwa ndikukonzanso zomwe zimakhudzidwa ndi kusunthika zimakhala ndi zoyipa pakulondola kwakanthawi kokhazikika komanso kukhazikika.
Choyipa chachikulu, oscillations mwina sangawonekere pa oscilloscope mwina chifukwa kuchuluka kwa oscilloscope ndikotsika kwambiri poyerekeza ndi kuchuluka kwa ma frequency oscillations omwe akuyesedwa, kapena chifukwa kuchuluka kwa kafukufuku wa oscilloscope ndikokwanira kuyimitsa kukomoka. Njira yabwino kwambiri ndikugwiritsa ntchito gulu lonse (low frequency to 15GHz pamwambapa) chowunikira chowunikira kuti muwone momwe matendawo amasinthira. Cheke ichi chiyenera kuchitika pamene zolowetsa zimasiyanasiyana pamitundu yonse yamphamvu, chifukwa nthawi zina ma parasitic oscillations nthawi zina amapezeka mgawo locheperako kwambiri.
Q: Kodi pali mafunso aliwonse okana zotsutsa?
A: Kukana kwa resistor sikukhazikika, koma kumasiyanasiyana ndi kutentha. Kutentha koyerekeza (TC) kumasiyana kuchokera PPM / ° C (miliyoni pa digiri Celsius) mpaka zikwi zingapo PPM / ° C. Ma resistor okhazikika kwambiri ndi bala lama waya kapena ma film osakanikirana ndi chitsulo, ndipo zoyipitsitsa ndizomwe zimapanga ma film film resistors.
Ma coefficients ofunda otentha nthawi zina amatha kukhala othandiza (a + 3500ppm / ° C resistor atha kugwiritsidwa ntchito kulipirira kT / Q mu mphambano ya diode yolumikizana, monga tafotokozera kale mu Q&AS for Application Engineers). Koma mukukaniza konse kutentha kumatha kukhala komwe kumapangitsa zolakwika m’madongosolo olondola.
Ngati kulondola kwa dera kumadalira machesi a ma resistor awiri okhala ndi ma coefficients osiyanasiyana otentha, ndiye ziribe kanthu kuti zikugwirizana bwanji ndi kutentha kamodzi, sizingafanane ndi zinazo. Ngakhale ma coefficients of the resistors awiri amafanana, palibe chitsimikizo kuti apitilizabe kutentha komweko. Kutentha komwe kumapangidwa ndimphamvu zamagetsi zamkati kapena kutentha kwakunja komwe kumafalikira kuchokera ku gwero la kutentha m’dongosolo kumatha kuyambitsa kusokonekera kwa kutentha, komwe kumayambitsa kukana. Ngakhale zotchinga zama waya apamwamba kapena zoyeserera zamafayilo azitsulo zimatha kukhala ndizofananira kutentha kwamazana (kapena ngakhale masauzande) PPM / ℃. Yankho lodziwikiratu ndikugwiritsa ntchito ma resistor awiri omangidwa kotero kuti onse ali pafupi kwambiri ndi matrix omwewo, kuti kulondola kwa dongosololi kukugwirizana bwino nthawi zonse. Gawoli likhoza kukhala zopangira ma silicon zomwe zimafanana ndi ma circuits ophatikizika, zokutira zamagalasi kapena makanema achitsulo. Mosasamala kanthu za gawo lapansi, ma resistor awiriwa amafanana bwino pakupanga, amakhala ndi ma coefficients ofanananso, ndipo ali pafupifupi kutentha komweko (chifukwa ali pafupi kwambiri).