LABORATORIUM MIERNICTWA CYFROWEGO |
III Informatyka Data wykonania : 29-11-1995 Nr w. 6 |
Temat: Pomiar wspóczynników tumienia zakoce woltomierza cyfrowego napicia staego. |
Wykonay : Maguda Katarzyna i kawa Agnieszka |
Cel wiczenia :[Author ID1: at Mon Dec 4 00:17:00 1995 ]
1. Wyznaczenie wspóczynnika tumiena sygnau naoonego (szeregowego) SMRR
w funkcji czstotliwoci.[Author ID1: at Tue Dec 5 04:53:00 1995 ]
[Author ID1: at Tue Dec 5 04:52:00 1995 ]2.[Author ID1: at Tue Dec 5 04:52:00 1995 ] Pomiar rzeczywistego wspóczynnika tumienia zakóce równolgych(wspólnych)CMRR dla waciwego poczenia ekranu i ekranu zwartego. [Author ID1: at Tue Dec 5 04:53:00 1995 ][Author ID1: at Tue Dec 5 05:30:00 1995 ]
1.1[Author ID1: at Tue Dec 5 04:51:00 1995 ] [Author ID1: at Sun Dec 3 23:36:00 1995 ]Na zajciach dokonaymy pomiaru wielkoci potrzebnych do wyznaczeniana wspóczynnika tumienia sygnau naoonego (szeregowego) SMRR w funkcji czstotliwoci.[Author ID1: at Sun Dec 3 23:33:00 1995 ]
Wspóczynnik tumienia sygnau naoonego charakteryzuje zdolno przetwornika A/C
lub woltomierza cyfrowego do tumienia zakóce szeregwego, nakadajcych si na napicie [Author ID1: at Wed Nov 29 22:18:00 1995 ]stae w[Author ID1: at Wed Nov 29 22:18:00 1995 ] obwodzie w[Author ID1: at Wed Nov 29 22:18:00 1995 ]ejciowym.
Tumienie zakóce sygnau naoonego zaley od stosunku Ti/Tn . Tumienie to mona opisa funkcj:
y = [Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ]x / |sin[Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ]x|
gdzie: x = Ti/ Tn
W celu scharakteryzowania tumienia zakóce wprowadza si wspóczynnik tumienia
sygnau naoonego wyraajcego si wzorem:
SMRR =20log[Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ]Un/[Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ] Umax[Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ]
gdzie:
[Author ID0: at Wed Aug 9 22:34:00 2000 ][Author ID0: at Wed Aug 9 22:34:00 2000 ]Umax -maksymalne wskazanie woltomierza cyfrowego
Un - amplituda napicia naoonego
W warunkach labolatoryjnych aby wyznaczy wspóczynnik tumienia sygnau naoonego, uywa si generatora napicia sinusoidalnego maych czstotliwoci jako
róda zakóce wczonego poprzez ukad transformatorowy. [Author ID1: at Wed Nov 29 22:22:00 1995 ]
[Author ID1: at Wed Nov 29 22:23:00 1995 ]1.[Author ID1: at Tue Dec 5 04:54:00 1995 ]2[Author ID1: at Wed Nov 29 22:23:00 1995 ] [Author ID1: at Wed Nov 29 22:23:00 1995 ] [Author ID1: at Wed Nov 29 22:22:00 1995 ]Schemat ukadu pomiarowego do wyznaczenia wspóczynnika SMRR .[Author ID1: at Wed Nov 29 22:22:00 1995 ][Author ID1: at Wed Nov 29 22:22:00 1995 ]
[Author ID1: at Wed Nov 29 22:22:00 1995
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Thu Nov 30 01:55:00 1995
]
1.[Author ID1: at Tue Dec 5 04:55:00 1995 ]3 Tabela pomiarowa [Author ID1: at Thu Nov 30 01:55:00 1995 ].[Author ID1: at Thu Nov 30 01:56:00 1995 ][Author ID1: at Sun Dec 3 09:07:00 1995 ]
Wartoci parametrów badanego[Author ID1: at Sun Dec 3 08:57:00 1995 ] woltomierza odczytane z jego danych technicznych :[Author ID1: at Sun Dec 3 08:57:00 1995 ]
- czas trwania pomiaru ( cakowania )[Author ID1: at Sun Dec 3 08:58:00 1995 ] [Author ID1: at Sun Dec 3 08:59:00 1995 ]T[Author ID1: at Sun Dec 3 08:58:00 1995 ]i[Author ID1: at Sun Dec 3 08:59:00 1995 ] = 20ms[Author ID1: at Sun Dec 3 08:59:00 1995 ]
- tumienie przebiegów - z filtrem [Author ID1: at Sun Dec 3 08:59:00 1995
] [Author ID1: at Sun Dec 3 09:01:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Sun Dec 3 09:03:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Wed Aug 9 22:34:00 2000
]60 dB[Author ID1: at Sun Dec 3 09:04:00 1995
]
- bez filtra [Author ID1: at Sun Dec 3 09:04:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Sun Dec 3 09:05:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Wed Aug 9 22:34:00 2000
] 90 dB .[Author ID1: at Sun Dec 3 09:05:00 1995
]
1.[Author ID1: at Tue Dec 5 04:55:00 1995 ]4 [Author ID1: at Sun Dec 3 22:44:00 1995 ]O[Author ID1: at Sun Dec 3 09:07:00 1995 ]bliczenia:[Author ID1: at Sun Dec 3 10:22:00 1995 ]
a) [Author ID1: at Mon Dec 4 00:43:00 1995 ]W warunkach laboratoryjnych aby wyznaczy wspóczynnik tumienia sygnau naoonego, uywa si generatora napicia sinusoidalnego maych czstotliwoci jako róda zakóce wczonego poprzez ukad transformator[Author ID1: at Mon Dec 4 00:42:00 1995 ]owy[Author ID1: at Mon Dec 4 00:42:00 1995 ] [Author ID1: at Tue Dec 5 04:57:00 1995 ].[Author ID1: at Mon Dec 4 00:42:00 1995 ] [Author ID1: at Tue Dec 5 04:57:00 1995 ]Na wejcie najlepiej poda U[Author ID1: at Tue Dec 5 04:56:00 1995 ]x [Author ID1: at Tue Dec 5 04:58:00 1995 ]= 0.[Author ID1: at Tue Dec 5 04:58:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ]
[Author ID1: at Mon Dec 4 00:42:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Mon Dec 4 00:42:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Wed Aug 9 22:34:00 2000
] [dB][Author ID1: at Mon Dec 4 00:45:00 1995
][Author ID0: at Thu Nov 30 00:00:00 1899
]
[Author ID1: at Mon Dec 4 00:42:00 1995 ]Umax -maksymalne wskazanie woltomierza cyfrowego [Author ID1: at Mon Dec 4 00:42:00 1995 ]
Un - amplituda napicia naoonego[Author ID1: at Mon Dec 4 00:42:00 1995 ]
b[Author ID1: at Mon Dec 4 01:20:00 1995 ]) [Author ID1: at Mon Dec 4 00:46:00 1995 ]Tabela oblicze do wyznaczenia charakterystyki idealnej wspóczynnika SMRR w funkcji stosunku czasu Ti/Tn.[Author ID1: at Mon Dec 4 00:46:00 1995 ][Author ID1: at Mon Dec 4 01:20:00 1995 ]
[Author ID1: at Mon Dec 4 01:13:00 1995 ]Tumienie zakóce sygnau naoonego zaley od stosunku Ti/Tn . Tumienie to mona opisa funkcj:[Author ID1: at Mon Dec 4 01:12:00 1995 ]
[Author ID1: at Mon Dec 4 01:12:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Mon Dec 4 01:12:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Wed Aug 9 22:34:00 2000
] , gdzie: x = Ti/ Tn[Author ID0: at Thu Nov 30 00:00:00 1899
]
W celu ilociowego scharakteryzowania tumienia zakóce wprowadza si wspóczynnik tumienia sygnau naoonego :[Author ID1: at Mon Dec 4 01:12:00 1995 ]
[Author ID1: at Mon Dec 4 01:12:00 1995 ]SMRR==20 log y [dB][Author ID0: at Thu Nov 30 00:00:00 1899 ]
2.1[Author ID1: at Tue Dec 5 05:01:00 1995 ] [Author ID1: at Tue Dec 5 05:02:00 1995 ] [Author ID1: at Tue Dec 5 05:04:00 1995 ] Wspóczynnik[Author ID1: at Tue Dec 5 05:02:00 1995 ] [Author ID1: at Tue Dec 5 05:04:00 1995 ] tumienia sygnau wspólnego CMRR[Author ID1: at Tue Dec 5 05:02:00 1995 ] charakteryzuje zdolno przetwornika a/c[Author ID1: at Tue Dec 5 05:02:00 1995 ] do tumienia zakóce równolegych[Author ID1: at Tue Dec 5 05:04:00 1995 ] .[Author ID1: at Tue Dec 5 05:08:00 1995 ] [Author ID1: at Tue Dec 5 05:19:00 1995 ]Nie zaley od czstotliwoci[Author ID1: at Tue Dec 5 05:18:00 1995 ] i okrela si[Author ID1: at Tue Dec 5 05:19:00 1995 ] [Author ID1: at Tue Dec 5 05:20:00 1995 ]go[Author ID1: at Tue Dec 5 05:19:00 1995 ] z zalenoci :[Author ID1: at Tue Dec 5 05:20:00 1995 ][Author ID1: at Tue Dec 5 05:19:00 1995 ]
CMRR = - 20 log [Author ID1: at Tue Dec 5 05:20:00 1995 ]ø[Author ID1: at Tue Dec 5 05:21:00 1995 ]U[Author ID1: at Tue Dec 5 05:20:00 1995 ]cm [Author ID1: at Tue Dec 5 05:21:00 1995 ]/ U[Author ID1: at Tue Dec 5 05:21:00 1995 ]2 [Author ID1: at Tue Dec 5 05:22:00 1995 ]ø[Author ID1: at Tue Dec 5 05:22:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ]
gdzie [Author ID1: at Tue Dec 5 05:22:00 1995 ]:[Author ID1: at Tue Dec 5 05:23:00 1995 ] U[Author ID1: at Tue Dec 5 05:22:00 1995 ]cm[Author ID1: at Tue Dec 5 05:22:00 1995 ] -[Author ID1: at Tue Dec 5 05:22:00 1995 ] [Author ID1: at Tue Dec 5 05:23:00 1995 ]napicie na generatorze[Author ID1: at Tue Dec 5 05:22:00 1995 ]
U[Author ID1: at Tue Dec 5 05:23:00 1995 ]2[Author ID1: at Tue Dec 5 05:23:00 1995 ] - spadek napicia na rezystancji R[Author ID1: at Tue Dec 5 05:23:00 1995 ]2[Author ID1: at Tue Dec 5 05:23:00 1995 ][Author ID1: at Tue Dec 5 05:28:00 1995 ]
2.2[Author ID1: at Tue Dec 5 05:12:00 1995
] [Author ID1: at Tue Dec 5 05:12:00 1995
] [Author ID1: at Tue Dec 5 05:24:00 1995
]Ukad do pomiaru rzeczywistego wspóczynnika tumienia zakóce wspólnych CMRR
[Author ID1: at Tue Dec 5 04:49:00 1995
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID1: at Tue Dec 5 04:49:00 1995
][Author ID0: at Wed Aug 9 22:34:00 2000
]
[Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Wed Aug 9 22:34:00 2000
][Author ID0: at Thu Nov 30 00:00:00 1899
]
2.3[Author ID1: at Tue Dec 5 04:31:00 1995
] Pomiar wspóczynnika tumienia sygnau wspólnego CMRR
[Author ID1: at Tue Dec 5 04:31:00 1995
]
2.3.1[Author ID1: at Tue Dec 5 04:31:00 1995 ] [Author ID1: at Tue Dec 5 05:26:00 1995 ] Z filtrem[Author ID1: at Tue Dec 5 04:31:00 1995 ]
2.3.2[Author ID1: at Tue Dec 5 05:26:00 1995 ] [Author ID1: at Tue Dec 5 05:27:00 1995 ] [Author ID1: at Tue Dec 5 05:27:00 1995 ]Bez filtru[Author ID1: at Tue Dec 5 04:31:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ]
60[Author ID1: at Tue Dec 5 04:31:00 1995 ].0[Author ID1: at Tue Dec 5 04:47:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ] |
3.[Author ID1: at Tue Dec 5 05:30:00 1995 ] [Author ID1: at Tue Dec 5 05:31:00 1995 ] Wnioski[Author ID1: at Tue Dec 5 05:30:00 1995 ] [Author ID1: at Tue Dec 5 05:30:00 1995 ][Author ID1: at Mon Dec 4 00:44:00 1995 ]
Celem naszego wiczenia byo wyznaczenie[Author ID1: at Tue Dec 5 05:34:00 1995 ]:[Author ID1: at Tue Dec 5 05:37:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ]
a)[Author ID1: at Tue Dec 5 05:36:00 1995 ] wspóczynnika tumienia sygnau naoonego dla ukadu [Author ID1: at Tue Dec 5 05:34:00 1995 ]SMRR [Author ID1: at Tue Dec 5 05:36:00 1995 ]z filtrem i bez filtra[Author ID1: at Tue Dec 5 05:34:00 1995 ] [Author ID1: at Tue Dec 5 05:35:00 1995 ][Author ID0: at Thu Nov 30 00:00:00 1899 ]
b) [Author ID1: at Tue Dec 5 05:37:00 1995 ]wspóczynnika tumienia sygnau wspólnego [Author ID1: at Tue Dec 5 05:35:00 1995 ]CMRR[Author ID1: at Tue Dec 5 05:35:00 1995 ] [Author ID1: at Tue Dec 5 05:36:00 1995 ].[Author ID1: at Tue Dec 5 05:34:00 1995 ] [Author ID1: at Tue Dec 5 05:36:00 1995 ][Author ID1: at Tue Dec 5 05:37:00 1995 ]
Z oblicze mona zaobserwowa, e wspóczynnik tumienia [Author ID1: at Tue Dec 5 05:34:00 1995 ]SMRR[Author ID1: at Tue Dec 5 05:34:00 1995 ] wzrasta wraz ze wzrostem stosunku czasu cakowania do czasu sygnau naoonego (Ti/Tn). Wzrost wspóczynnika tumienia SMRR dla tego samego stosunku Ti/Tn jest wikszy dla ukadu z filtrem. Prawd tych wniosków dowodz obliczenia zawarte w tabeli oblicze. [Author ID1: at Tue Dec 5 05:34:00 1995 ] [Author ID1: at Tue Dec 5 05:41:00 1995 ] Do sprawozdania doczamy wykres charakterystyki idealnej, co umoliwia porównanie i obserwacj rónic pomidzy t charakterystyk a charakterystykami rzeczywistymi uzyskanymi podczas wiczenia. Przy analizie mona stwierdzi, e maksima tumienia, przypadaj na cakowite wielokrotnoci Ti/Tn. Wszelkie niezgodnoci (nieprawidowoci) wynikaj z nied[Author ID1: at Tue Dec 5 05:34:00 1995 ]o[Author ID1: at Tue Dec 5 05:39:00 1995 ]skonaoci sprztu pomiarowego.[Author ID1: at Tue Dec 5 05:34:00 1995 ] [Author ID1: at Tue Dec 5 05:41:00 1995 ]Zakócenia szeregowe SMRR s napiciami zakócajcymi zmiennymi dodajcymi si do n[Author ID1: at Tue Dec 5 05:32:00 1995 ]a[Author ID1: at Tue Dec 5 05:32:00 1995 ]picia staego mierzonego przez woltomierz cyfrowy. Napicia tego radzaju s spowodowane przez pola elektromagnetyczne w przewodach wejciowych lub s skadow mierzonego na[Author ID1: at Tue Dec 5 05:32:00 1995 ]pi[Author ID1: at Tue Dec 5 05:43:00 1995 ]cia (ttnienia). Czstotliwoci tych napi s wielokrotnociami czstotliwoci sieciowej. [Author ID1: at Tue Dec 5 05:32:00 1995 ][Author ID1: at Tue Dec 5 05:46:00 1995 ]
Wspóczynnik tumienia sygnau wspólnego [Author ID1: at Tue Dec 5 05:32:00 1995 ]CMRR [Author ID1: at Tue Dec 5 05:32:00 1995 ]moe by uwaany za[Author ID1: at Tue Dec 5 05:47:00 1995 ] wspóczynnik tumienia przy przeksztacaniu sygnaów wspólnych (równolegych ) w[Author ID1: at Tue Dec 5 05:48:00 1995 ] normale (szeregowe)[Author ID1: at Tue Dec 5 05:49:00 1995 ] .[Author ID1: at Tue Dec 5 05:51:00 1995 ] [Author ID1: at Tue Dec 5 05:47:00 1995 ]Warto [Author ID1: at Tue Dec 5 05:51:00 1995 ]jego [Author ID1: at Tue Dec 5 05:52:00 1995 ]zmienia si w sposób nieznaczny[Author ID1: at Tue Dec 5 05:32:00 1995 ] [Author ID1: at Tue Dec 5 05:53:00 1995 ]i nie zaley od czstotliwoc[Author ID1: at Tue Dec 5 05:32:00 1995 ]i .[Author ID1: at Tue Dec 5 05:53:00 1995 ][Author ID1: at Tue Dec 5 05:32:00 1995 ]
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