Kev tshuaj xyuas ntawm cov tswv yim kho EMI tiag tiag rau kev hloov cov khoom siv hluav taws xob
Kev faib tawm thiab cov qauv EMC:
EMC (Electromagnetic Compatibility) yog electromagnetic compatibility, uas suav nrog EMI (electromagnetic harassment) thiab EMS (electromagnetic anti-harassment). EMC txhais tau tias: lub peev xwm ntawm lub cuab yeej lossis lub cev ua haujlwm ib txwm nyob hauv nws qhov chaw electromagnetic yam tsis ua rau muaj kev cuam tshuam tsis zoo ntawm electromagnetic cuam tshuam rau txhua yam hauv ib puag ncig. EMC yog hu ua electromagnetic compatibility. EMP hais txog electromagnetic pulse.
EMC=EMI + EMS EMI: Electromagnetic cuam tshuam EMS: Electromagnetic compatibility (kev tiv thaiv)
EMI tuaj yeem muab faib ua ob ntu: conduction thiab hluav taws xob.
Kev qhia tshwj xeeb feem ntau tuaj yeem muab faib ua: FCC Tshooj 15J Chav B; CISPR 22 (EN55022, EN61000-3-2, EN61000-3-3) Chav B;
National standard IT qeb (GB9254, GB17625) thiab AV qeb (GB13837, GB17625).
FCC xeem zaus yog 450K-30MHz, CISPR 22 xeem zaus yog 150K--30MHz, Kev coj tuaj yeem kuaj nrog lub ntsuas spectrum, thiab Radiation yuav tsum tau sim hauv chav kuaj tshwj xeeb.
EMI yog electromagnetic cuam tshuam. EMI yog ib feem ntawm EMC. EMI (Electronic Magnetic Interference) electromagnetic cuam tshuam. EMI muaj xws li conduction, hluav taws xob, tam sim no harmonics, voltage flicker, thiab lwm yam Electromagnetic cuam tshuam yog tsim los ntawm peb qhov chaw: cuam tshuam qhov chaw, coupling channel thiab receiver, uas feem ntau hu ua peb lub ntsiab ntawm kev cuam tshuam. EMI yog linearly proportional rau tam sim no, tam sim no voj cheeb tsam thiab square ntawm zaus: EMI=K*I*S*F2. Kuv yog qhov tam sim no, S yog lub voj voog, F yog qhov zaus, thiab K yog qhov tsis tu ncua ntawm cov khoom siv hauv Circuit Court thiab lwm yam.
Kev cuam tshuam hluav taws xob (30MHz-1GHz) tau nthuav tawm los ntawm qhov chaw thiab raws li cov yam ntxwv thiab cov cai ntawm cov hluav taws xob nthwv dej. Tab sis tsis yog ib qho cuab yeej tuaj yeem ua hluav taws xob hluav taws xob.
Kev cuam tshuam ua haujlwm (150K--30}MHz) yog kev cuam tshuam uas nthuav tawm nrog cov neeg siv khoom. Yog li ntawd, kev nthuav tawm ntawm kev cuam tshuam kev cuam tshuam yuav tsum muaj kev sib txuas ua tiav ntawm qhov cuam tshuam ntawm qhov chaw thiab tus txais.
EMI hais txog kev cuam tshuam sab nraud electromagnetic ntawm cov khoom. Feem ntau, nws muab faib ua ob theem: Chav A & Chav B. Chav A yog qib kev lag luam thiab Chav B yog qib pej xeem. Cov neeg siv rau pej xeem yog nruj dua li cov siv rau kev lag luam, vim tias cov hluav taws xob tso cai rau kev lag luam siv me ntsis loj dua. Hais txog kev ntsuas hluav taws xob ntawm tib yam khoom hauv EMI kuaj, ntawm 30-230MHz, Chav B xav kom cov hluav taws xob txwv tsis pub dhau 40dBm, thaum Class A xav kom cov hluav taws xob txwv tsis pub dhau 50dBm (siv peb- meter anechoic chamber ntsuas raws li ib qho piv txwv), uas yog kuj xoob. Feem ntau hais lus, CLASSA txhais tau hais tias nyob rau hauv EMI kev sim ntsuas, yam tsis muaj kev cuam tshuam tus neeg teb xov tooj, cov cuab yeej siv tau txuas ntxiv mus ua haujlwm raws li qhov xav tau, thiab tsis muaj kev ua haujlwm tsis zoo lossis kev ua haujlwm poob qis dua qib kev ua haujlwm tau tso cai.
EMI ntsuas cov hluav taws xob thiab kev ua haujlwm ntawm cov khoom siv thaum nws ua haujlwm ib txwm. Thaum kuaj, muaj ob qhov txwv siab tshaj plaws rau EMI hluav taws xob thiab kev coj ua ntawm tus txais, uas sawv cev rau Class A thiab Class B feem. Yog tias qhov pom waveform dhau ntawm B kab tab sis qis dua A kab, ces cov khoom yog Class A. EMS siv cov cuab yeej ntsuas los cuam tshuam cov khoom thiab saib seb cov khoom puas tuaj yeem ua haujlwm ib txwm nyob rau hauv kev cuam tshuam. Yog tias nws ua haujlwm ib txwm lossis tsis muaj kev ua haujlwm tsis zoo tshaj li cov qauv, nws raug ntsuas A. Nws tuaj yeem rov pib dua thiab yuav tsis muaj kev ua haujlwm degradation tshaj li tus qauv yuav tsum tau ua tom qab rov pib dua, uas yog Chav B. Yog tias nws tsis tuaj yeem rov pib dua thiab xav tau rov pib dua manually, nws raug cais raws li qib C. Yog tias nws ua tsis tau, nws raug cais raws li qib D. Lub teb chaws tus qauv muaj D-theem kev cai, thiab EN tsuas yog muaj A, B, thiab C. EMI yog qhov nyuaj tshaj plaws los daws ntawm khib ntau ntau ntawm kev khiav hauj lwm zaus.
