DSO138 USB Lub Hwj Chim: Tsis Txhawb Boost!: 3 Cov Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:25

JYE DSO138 yog lub oscilloscope me me zoo heev rau kev ua haujlwm suab thiab yuav ua rau lub teeb liab nqa tau zoo. Qhov teeb meem yog, nws tsis yog nqa tau tiag tiag vim tias nws xav tau 9V lub zog hloov pauv. Nws yuav zoo dua yog tias nws tuaj yeem muab los ntawm tus qauv USB lub txhab nyiaj fais fab lossis ib qho khoom siv USB. Rau qee qhov laj thawj JYE tsis siv sijhawm los ua tus thawj DSO138 nkaus USB zog, uas yog coj txawv txawv vim nws yooj yim heev ua. PCB txawm suav nrog USB txuas, tab sis nws tsis ua dab tsi! (Muaj qhov hloov tshiab DSO138 MINI uas yog USB siv, tab sis cov neeg feem coob zoo li yog tus tswv qub).

Muaj cov lus qhia hauv is taws nem qhia koj yuav ua li cas ntxiv tus tswj hwm hloov pauv USB zog rau hauv 9V, tab sis qhov ntawd tsis muaj txiaj ntsig thiab tsis tsim nyog. Hauv cov lus qhia no kuv yuav qhia koj yuav siv lub on-board USB txuas ncaj qha rau lub zog siv. Kuv kuj tseem suav nrog ib qho kev xaiv los tshem tawm cov teeb meem cuam tshuam tsis zoo uas tshwm sim ntawm qee qhov nce nqis.

Kuv tau kos qhov tsim nyog mods ntawm thawj JYE schematic ua ke nrog cov duab ntawm kuv hloov pauv PCB.

Khoom siv

Qee qhov sib txuas hlau 100uH 100mA (lossis ntau dua) inductor2.2k resistor470pF rau 1nF capacitor3k resistor (yeem) 1.8k resistor (yeem) 1.2k resistor (yeem)

Kauj ruam 1:

Tshem tawm D2. Qhov no yog kev tiv thaiv kev nyab xeeb kom tsis txhob siv lub DC fais fab qub. Qhov no yuav ua kom tsis muaj dab tsi mus tsis raug yog tias koj yuam kev ntsaws lub qub DC fais fab mov tom qab koj tau ua tiav USB lub zog hloov pauv.

Siv cov xaim hluav taws xob los ntawm lub ncoo sau VBUS rau daim ntawv lo cim npe +5V. (Cov no tau sau npe TP33 thiab TP21 ntawm cov txheej txheem). Qhov no txuas tus USB fais fab tus pin rau lub Circuit Court 5V fais fab kev tsheb nqaj hlau. Cov tsheb nqaj hlau +3V tau txais los ntawm qhov hluav taws xob los ntawm U3 uas tsis xav tau kev hloov pauv.

Tam sim no tshem tawm U5 thiab muab cov xaim txuas nruab nrab ntawm ob daim ntaub qhwv sab nraud, kom jumper hla qhov uas nws tau siv.

Qhov no saib xyuas ntawm txoj kab hluav taws xob zoo, hauv cov kauj ruam tom ntej peb yuav hloov kho txoj kev tsis zoo yog li nws ua haujlwm tawm 5V USB ib yam nkaus.

Kauj ruam 2:

DSO138 Circuit Court siv qhov hloov pauv yooj yim hloov pauv kom ua rau qhov tsis zoo qhov hluav taws xob uas yog tom qab ntawd tswj hwm rau -5V los ntawm U4. Txawm hais tias muaj kev tawm tswv yim network rau CPU los ntawm R41/42, nws zoo li JYE tsis tau siv nws hauv cov khoom lag luam, CPU yooj yim tsim 17.6kHz teeb liab txuas ntxiv ntawm R40. Qhov no txhais tau tias peb yuav tsum hloov kho lub Circuit Court kom ua haujlwm los ntawm 5V USB khoom siv.

Hloov L2 nrog 100uH inductor (ntsuas rau 100mA lossis ntau dua). Kuv muaj ib qho hauv kuv lub thawv khib nyiab. Kuv yuav tsum khoov ob txhais ceg me ntsis kom nws haum rau tib qho chaw.

Ntxiv cov snubbing network hla D1 suav nrog lub capacitor hauv koob nrog 2.2k ohm resistor. Nws tsis muaj teeb meem dab tsi hom capacitor koj siv, tab sis tus nqi yuav tsum yog nruab nrab ntawm 470pF thiab 1nF. Kuv siv lub hau yas 1nF vim tias qhov kuv muaj. Qhov no yuav ntxuav qhov kev hloov pauv yoj.

Koj ua tiav! Tam sim no koj tuaj yeem txuas rau hauv USB cable thiab ntsuas qhov ntsuas hluav taws xob ntawm PCB cov ntawv xeem uas yuav tsum tseem yog -5V, +5V thiab 3.3V. Cov kauj ruam tom ntej yog nyob ntawm yeem.

Kauj ruam 3:

Thaum saib cov cim loj koj yuav tau pom qhov tsis sib xws ntawm cov duab yoj. Qhov no tshwm sim los ntawm kev thauj khoom ntau dhau ntawm U2B los ntawm cov peev txheej faib R6/7/8. Kev daws yog yooj yim:

Hloov R6, R7 thiab R8 nrog cov resistors kaum zaug ntau dua hauv tus nqi, piv txwv li R6 = 3k, R7 = 1.8k, R8 = 1.2k.