Yuav daws qhov teeb meem Switching Power Supply Overradiation li cas
EMI yog qhov ntsuas hluav taws xob thiab kev ua haujlwm ntawm lub cuab yeej thaum lub sijhawm ua haujlwm. Thaum lub sij hawm sim, muaj ob lub siab txwv rau EMI hluav taws xob thiab conduction ntawm lub receiver, sawv cev rau Class A thiab Class B. Yog hais tias qhov kev soj ntsuam waveform tshaj kab ntawm B tab sis ntog hauv qab kab ntawm A, ces cov khoom raug cais raws li Class A. EMS siv cov cuab yeej ntsuas los cuam tshuam cov khoom thiab saib seb lawv puas tuaj yeem ua haujlwm ib txwm nyob hauv kev cuam tshuam. Yog tias lawv ua haujlwm ib txwm lossis tsis muaj kev ua haujlwm tsis zoo dhau qhov kev xav tau, nws raug cais raws li Chav A. Nws tuaj yeem rov pib dua yam tsis muaj kev ua haujlwm tsis zoo dua li cov qauv yuav tsum tau ua, thiab raug cais raws li qib B. Tsis tuaj yeem rov pib dua, phau ntawv rov pib dua yog suav tias yog C-theem, thiab tsis ua haujlwm yog suav tias yog D-theem. Lub teb chaws tus qauv muaj D-qib cov kev cai, thaum EN tsuas yog muaj A, B, thiab C. EMI yog qhov nyuaj tshaj plaws ntawm qhov sib txawv ntawm qhov ua haujlwm zaus.
EMS (Electromagnetic Suseepibilkr) electromagnetic rhiab heev yog feem ntau hu ua "electromagnetic immunity", uas yog hais txog lub peev xwm ntawm cov cuab yeej los tiv thaiv kev cuam tshuam sab nraud thiab cuam tshuam, thaum EMI hais txog kev cuam tshuam sab nraud ntawm cov khoom siv.
The level in EMS refers to Class A, where the equipment is still working normally after testing is completed; Class B, Can work normally after testing is completed or needs to be restarted during testing; Class C, Can restart and work normally after manual adjustment; Class D, The device is damaged and cannot be started no matter how it is adjusted. The strictness level of EMI is B>A, and EMS is A>B>C>D.
Tua lub hwj chim input
EMI Circuit Court:
Lub luag haujlwm ntawm X capacitor:
Tshem tawm cov suab nrov sib txawv, qhov loj dua qhov capacitance, qhov zoo dua qhov cuam tshuam ntawm cov suab nrov tsawg zaus.
Lub luag haujlwm ntawm Y capacitor:
Ncua hom suab nrov, qhov loj dua qhov capacitance, qhov zoo dua cov nyhuv ntawm suppressing suab nrov tsawg zaus. Y capacitor muab lub voj impedance qis los ntawm theem nrab mus rau hauv av thawj, ua rau cov dej ntws mus rau hauv av thiab rov qab los ntawm LISN mus rau luv luv Circuit Court. Vim qhov tsis tiav zoo tagnrho ntawm Y capacitor, kuj tseem muaj impedance ntawm ntau qhov chaw ntawm theem nrab, yog li nws tsis tuaj yeem ua rau tag nrho lawv rov qab los. Ib txhia tseem ntws mus rau hauv av. Lub Y capacitor yuav tsum tau txuas ncaj qha rau hauv av txias ntawm thawj thiab theem nrab siv txoj kab ncaj nraim. Yog tias dv / dt ntawm MOS thaum tig rau ntau dua dv / dt thaum muab tua, ces Y capacitor txuas nrog hauv av ntawm thawj; Hloov pauv, txuas rau V +.
Kev ua haujlwm ntawm hom hom inductance:
Nrawm hom suab nrov, qhov loj dua qhov inductance, qhov zoo dua qhov cuam tshuam ntawm cov suab nrov tsawg zaus. Ua kom cov impedance ntawm hom hom tam sim no thiab txo cov hom hom tam sim no.
Kev ua haujlwm ntawm qhov sib txawv inductance:
Tshem tawm cov suab nrov sib txawv, qhov loj dua qhov inductance, qhov zoo dua qhov cuam tshuam ntawm cov suab nrov tsawg zaus.
General EMI cov tswv yim teb ua ntej tsim cov khoom siv hluav taws xob hloov pauv
Txais AC input EMI lim
