Yuav ua li cas oscilloscope probes ntsuas lub cev muaj nuj nqis xws li lub sij hawm, zaus thiab voltage qhov tseem ceeb
Koj yuav tsum coj lub oscilloscope sojntsuam sib nrug ua ntej kom pom dab tsi sab hauv. Ntawm ntu uas txuas mus rau oscilloscope yog BNC connector, yog tias koj tsis siv BNC connector tab sis siv ob lub xov hlau coj cov teeb liab ncaj qha mus rau hauv oscilloscope, koj yuav pom tias lub teeb liab yog distorted, square nthwv dej mus rau hauv. thiab qhia ib tug sawtooth yoj! Vim li cas qhov no?
Oscilloscopes feem ntau yog siab dua input impedance los txo qhov cuam tshuam ntawm Circuit Court hauv kev sim. Yog li koj yuav pom 1M ohm resistor lossis zoo sib xws hauv qab qhov kev sojntsuam BNC connector. Qhov no muaj ob qho zoo thiab qhov tsis zoo, qhov me me sab nraud capacitance tus nqi kuj tuaj yeem ua rau lub lim los ntawm cov tswv yim, uas tuaj yeem cuam tshuam qhov ntsuas waveform. Qhov no yuav daws tau li cas nyob ntawm seb qhov kev sojntsuam raug daws li cas!
Feem ntau, oscilloscope probes siv lub capacitor adjustable nyob rau hauv parallel kom tshem tawm cov nyhuv ntawm no ib feem ntawm cable. Qee qhov kev them nyiaj capacitors tso cai rau peb ua peb tus kheej hloov kho thiab xaiv cov txiaj ntsig zoo tshaj plaws. Oscilloscopes muaj ib lub xwmfab yoj qhov chaw, yog li peb txuas qhov kev sojntsuam mus rau qhov chaw thiab kho lub capacitor kom cov square nthwv dej tso rau ntawm qhov screen yog tus qauv tshaj plaws "square yoj". Ntau dhau capacitance yuav ua rau qhov kev sojntsuam tsim cov lim dej qis, thaum qhov kev tawm tsam yuav muaj tseeb rau lub lim dej siab. Yog li ntawd yuav tsum tau kho kom zoo.
Square nthwv dej ntsuas nrog qhov ntsuas tsis tau kho
Kev sojntsuam kuj tseem muaj lub attenuator, uas ua rau lub teeb liab nyob rau hauv kev sim. Lub attenuator feem ntau yog qhov tseem ceeb ntawm 10. ib qho 1V teeb liab yuav tshwm sim li 100mV. qee qhov oscilloscopes tuaj yeem paub txog lub xeev ntawm kev sojntsuam thiab tso saib tus nqi raug.
Kev sojntsuam siv cov yam ntxwv siab impedance los xyuas kom meej tias lub Circuit Court tsis cuam tshuam los ntawm qhov ntsuas qhov ntsuas, tab sis muaj qee lub sijhawm peb yuav tsum ntsuas qee qhov Circuit Court nrog qhov ntsuas impedance tsawg. Piv txwv li, 50 ohm impedance RF tso zis Circuit Court yog ib qho teeb meem ntawm nias lub pob rau lub tshuab uas muaj 50 ohm impedance ntsuas; tab sis rau ib txwm oscilloscope, qhov no yog thaum qhov kev sojntsuam tsis haum rau kev ntsuas. Koj yuav tsum phim nws nrog BNC tee thiab 50 ohm kawg resistor, thiab txuas ncaj qha mus rau 50 ohm tso tawm ntawm lwm qhov kawg.
