Dab tsi yog qhov sib txawv ntawm diodes hauv DC thiab AC systems?

Ib, Qhov txawv ntawm lub cev mechanisms: bidirectional adaptation ntawm unidirectional conductivity
Cov yam ntxwv tseem ceeb ntawm lub diode los ntawm unidirectional conductivity ntawm PN hlws ris: nws ua thaum pem hauv ntej biased (nrog ib tug tsis kam ntawm kaum tawm ohms) thiab tua thaum rov qab biased (nrog ib tug kuj ntawm megaohms). Cov yam ntxwv no yuav tsum tau ua kom haum raws li kev sib txawv hauv DC thiab AC systems.

DC system: static unidirectional tswj
Nyob rau hauv DC system, diodes nyob rau hauv ib tug ruaj khov unidirectional conducting los yog txiav tawm lub xeev. Piv txwv li, nyob rau hauv lub tsheb npav DC ntawm lub photovoltaic inverter, parallel freewheeling diodes txuas ntxiv ua thaum lub IGBT raug muab tua, muab txoj kev freewheeling rau lub inductor tam sim no. Nws qhov DC tsis kam (rau pem hauv ntej voltage poob ntawm 0.7V) txiav txim siab poob lub zog, thaum lub sij hawm rov qab los (feem ntau yog qib nanosecond) muaj qhov cuam tshuam me me hauv DC scenarios.

Kev sib txuas lus system: dynamic voj voog hloov
Nyob rau hauv kev sib txuas lus systems, diodes yuav tsum tau sai sai hloov lawv conduction xeev ntawm qhov zoo thiab tsis zoo ib nrab voj voog ntawm 50Hz / 60Hz. Siv tus choj rectifier Circuit Court ua piv txwv, plaub lub diodes ua hloov pauv hloov AC zog rau hauv lub zog DC. Nyob rau lub sijhawm no, AC tsis kam ntawm diode (uas txawv nrog zaus) thiab lub sijhawm rov qab los (uas cuam tshuam rau siab -frequency poob) dhau los ua qhov tseem ceeb. Piv txwv li, ceev rov qab diodes (rov qab lub sij hawm rov qab<50ns) can reduce conduction losses by 15% in high-frequency switching power supplies.

2, Core functions nyob rau hauv DC systems
1. Kev tiv thaiv polarity thiab rov qab cais
Nyob rau ntawm qhov kawg ntawm cov khoom siv DC, ib qho kev sib txuas ntawm diode tuaj yeem tiv thaiv cov khoom siv hluav taws xob los ntawm kev thim rov qab. Thaum lub polarity thim rov qab, lub diode raug rau qhov rov qab voltage thiab txiav tawm, zam kev puas tsuaj tom ntej. Piv txwv li, lub tsheb charger siv 1N4007 diode (rov qab tiv taus voltage 1000V), uas tuaj yeem tiv taus qhov hluav taws xob hloov pauv thaum lub tsheb roj teeb rov qab.

2. Txuas ntxiv ntws thiab lub zog tso tawm
Nyob rau hauv lub inductive load Circuit Court, diodes muab ib tug freewheeling txoj kev rau lub inductor tam sim no. Nyob rau hauv tus neeg tsav tsheb lub cev muaj zog, lub freewheeling diode ua thaum lub IGBT raug kaw los tiv thaiv lub nraub qaum electromotive quab yuam ntawm inductor los ntawm kev nkag mus rau lub raj hloov. Nws cov yam ntxwv thim rov qab ncaj qha cuam tshuam rau kev ua haujlwm zoo: cov diodes zoo tib yam muaj lub sijhawm rov qab los ntawm 200ns, thaum Schottky diodes (tsis muaj cov txheej txheem rov qab) tuaj yeem txhim kho kev ua haujlwm ntawm 3% -5%.

3. Voltage stabilization thiab voltage clamping
Zener diodes ua tiav cov kev cai voltage hauv DC systems. Piv txwv li, ib tug 5.1V Zener diode txuas nyob rau hauv parallel nyob rau hauv ib tug 12V DC fais fab mov yuav stabilize qhov tso zis voltage ntawm 5.1V ± 5%. Lub zog tsis kam (feem ntau yog ob peb ohms) txiav txim siab qhov tseeb ntawm qhov hluav taws xob stabilization, thaum lub hwj chim dissipation muaj peev xwm (xws li 1W, 5W ntim) txiav txim siab ntawm daim ntawv thov scenario.

3, Cov haujlwm tseem ceeb hauv kev sib txuas lus
1. Rectification thiab waveform hloov dua siab tshiab
Kev kho yog qhov tseem ceeb ntawm diodes hauv AC systems. Nyob rau hauv ib nrab nthwv dej rectification Circuit Court, ib lub diode converts alternating tam sim no rau hauv pulsating ncaj tam sim no, nrog ib tug efficiency ntawm kwv yees li 40.6%; Kev ua tau zoo ntawm tag nrho nthwv dej rectification Circuit Court (chaw kais transformer + ob lub diodes) tau txhim kho rau 81.2%; Tus choj rectifier Circuit Court (plaub diodes) ua tiav tag nrho nthwv dej rectification yam tsis tas yuav tsum muaj qhov chaw kais dej, dhau los ua cov kev daws teeb meem loj.

2. Kev kuaj pom thiab teeb liab demodulation
Hauv kev sib txuas lus wireless, diodes ua tiav siab -ntau zaus teeb liab pom. Piv txwv li, nyob rau hauv AM xov tooj cua, diodes siv unidirectional conductivity los rho tawm suab signals, thiab lawv junction capacitance (feem ntau ob peb picofarads) cuam tshuam rau siab - zaus teb. Yog li ntawd, yuav tsum tau xaiv lub diode rau kev kuaj pom (xws li 1N34A) .

3. zaus hloov dua siab tshiab thiab sib xyaw siv
Nyob rau hauv siab - zaus circuits, cov yam ntxwv nonlinear ntawm diodes pab hloov zaus. Nyob rau hauv ib tug tov khoom, ib tug muab ob npaug rau cov qauv uas muaj xws li ob diodes yuav sib tov lub input teeb liab nrog lub zos oscillator teeb liab los tsim ib tug intermediate zaus teeb liab. Lub hlws ris capacitance thiab series kuj txiav txim qhov sib tov efficiency, thiab nto mount diodes (xws li HSMS-286x series) yuav tsum tau siv los txo cov kab mob parasitic.

4, Kev sib piv ntawm cov ntawv thov raug xwm txheej
Functional Dimension DC System Application AC System Daim Ntawv Thov
Kev tiv thaiv muaj nuj nqi: kev tiv thaiv hluav taws xob rov qab, inductor surge voltage suppression, EMI filtering
Lub zog hloov hluav taws xob photovoltaic cell MPPT tswj, roj teeb them AC-DC hloov dua siab tshiab, hloov pauv zaus tsav
Kev tsim cov teeb liab, kev tswj hluav taws xob, kev tsim kho qhov rooj logic, nrhiav kom tau thiab demodulation, zaus sib xyaw modulation
Cov khoom siv xws li Schottky diodes, Zener diodes, ceev rov qab diodes, thiab rectifier diodes
5, Kev ua tsis tiav hom thiab cov teebmeem hauv lub cev
DC system tsis ua hauj lwm: kev pheej hmoo ntawm luv luv Circuit Court thiab thermal runaway
Hauv DC systems, diode tawg (tshwj xeeb tshaj yog thermal tawg) tuaj yeem ua rau luv luv Circuit Court. Piv txwv li, kev tawg ntawm lub freewheeling diode nyob rau hauv ib tug photovoltaic inverter yuav ua rau lub DC lub tsheb npav voltage ncaj qha mus rau lub IGBT collector, ua rau lub module tawg. Hom kev txhaum no yuav tsum muaj kev tiv thaiv dual los ntawm kev txwv tam sim no (xws li 0.1 Ω / 5W) thiab fuses.

Kev sib txuas lus tsis ua haujlwm: waveform distortion thiab system tuag tes tuag taw
Hauv kev sib txuas lus, kev degradation ntawm diode tsis (xws li lub sij hawm rov qab mus rau lub sij hawm ntev) tuaj yeem ua rau muaj kev cuam tshuam ntawm kev hloov kho waveform. Nyob rau hauv tus neeg tsav tsheb lub cev muaj zog, thaum lub sij hawm rov qab los ntawm lub rectifier diode nce los ntawm 50ns mus rau 200ns, lub harmonic distortion nce los ntawm 3% mus rau 12%, ua rau lub cev muaj zog vibration mus intensified. Hom kev ua txhaum no yuav tsum muaj kev saib xyuas los ntawm kev saib xyuas online ntawm diode hlws ris kub (infrared thermography).