實(shí)驗(yàn)手冊電磁學(xué)40歐姆定律

1、實(shí)驗(yàn)Experiment P40: Ohms Law 歐姆定律(er Amplifier)（功率放大器）Concept: basic electricity概念：基礎(chǔ)電學(xué) Time: 30 mSWMacerface: 700osh_ file: P40 Ohms LawWindows_ file: P40_OHM.SWSEQUIPMENT NEEDED所需儀器Science Workshop_erfaceer Amplifier 功率放大器(2) Patch Cords 接插線FROM AC/DC ELECTRONICS LAB*來自AC/DC電子學(xué)light bulb, 3 volt燈泡，3

2、 v resistor, 10 ohm 電阻器，10歐姆(2) wire leads, 10 inch 引線，10英寸(*The AC/DC Electronics Laboratory is AC/DC電子學(xué)是 PASCO EM-8656.)PURE目的The pure of this laboratory activity is to investigate the relationship betn current andvoltage in Ohmic and non-Ohmic materials.本實(shí)驗(yàn)的目的是電壓之間的關(guān)系。歐姆和非歐姆材料的電流和THEORY原理Ohm disc

3、overedt when the voltage (potential difference) across a resistor changes, thecurrent through the resistor changes. He expressed this as I = V/R (current is directlyproportional to voltage and inversely proportional to). In other words, as the voltageincreases, so does the current. The proportionali

4、ty constant is the value of the. Thecurrent is inversely proportional to the. As theincreases, the currentdecreases. 歐姆發(fā)現(xiàn)當(dāng)加在一個(gè)電阻上的電壓（電勢差）改變時(shí)，通過電阻器的電流也改變。他把這個(gè)表示為I = V/R（電流與電壓成正比，與電阻成反比）。換句話說，當(dāng)電壓升高時(shí)，電流也升高。這個(gè)比例常數(shù)就是電阻，電流與電阻成反比。當(dāng)電阻升高時(shí)，電流降低。If the voltage across an “Ohmic” resistor is increased, a graph o

5、f voltage versus current shows astraight line (indicating a constant). The slope of the line is the value of thet is, if the resistor is “non-Ohmic”), the graph of voltage.However, if thechanges (versus current will not be a straight line. Instead, it will show a curve wichanging slope.如果加在一個(gè)歐姆電阻上的電

6、壓升高，電壓電流的圖表將顯示一條直線（表示一個(gè)恒定的電阻）。然而，如果電阻是可變的（即電阻是非歐姆型的），則電壓電流圖表將不會是一條直線，而是一條斜率變化的曲線。For a typical resistor, the value of itsdoes not change apprebly. However, for alight bulb, theof the filament will change as it heats up and cools down. At high ACfrequencies, the filament doesnve time to cool down, so

7、 it remains at a nearly constanttemperature and the one Hertz), the filamenstays relatively constant.ow AC frequencies (e.g., lessns time to change temperature. As a consequence, theof thefilament changes dramatically and the resulting change in current through the filament iseresting to watch.對于一個(gè)典

8、型的電阻來說，它的電阻值不會有一點(diǎn)改變。然而，對于一個(gè)燈泡來說，燈絲的電阻在變熱或冷卻時(shí)會發(fā)生改變，hepart of thiivity, you will investigate a ten ohm (_) resistor.he second part, youwill investigate the filament of a small light bulb.在本實(shí)驗(yàn)的第一部分，你將一個(gè)10歐姆電阻器。在第二部分，你將一個(gè)小燈泡的燈絲。PROCEDURE A Ten Ohm Resistor步驟A10歐姆電阻器his part of the activity, theer Amplif

9、iers voltage to a ten ohm resistort ismounted on the AC/DC Electronics Lab circuit board. The Science Workshoperface measuresthe output voltage to the resistor, and the currentt is drawn from theer Amplifier. 在這一部分實(shí)驗(yàn)率放大器對一個(gè)安裝在AC/DC電子線路板上的10歐姆電阻提供電壓。Science Workshop接口將測量對電阻器的輸出電壓，以及從功率放大器流出的電流。The Sc

10、ience Workshop program collects and displays the voltage and current. You can use a plotof voltage vs. current to confirm thevalue of the resistor. Science Workshop程序?qū)⑹占@示電壓和電流值。你可以用電壓電流曲線來確定電阻器的電阻。PART I: Computer Setup計(jì)算機(jī)設(shè)置1.將Science Workshop接口連接到電腦上，打開接口，然后打開電腦。2.將功率放大器模擬通道A。將電源插頭一個(gè)適當(dāng)?shù)牟遄４蜷_下述標(biāo)題的

11、Science Workshop文件：功率放大器的背面，然后把插頭連接到3.1.Connect the Science Workshopthe computer.erface to the computer, turn on theerface, and turn on2.Plug theer Amplifieroog Channel A. Plug theer cordo the back of theer Amplifier and connect theer cord to an appropriate electrical outlet.3.Open thetitled as show

12、n:MacoshWindowsP40 Ohms LawP40_OHM.SWSTheopens wiScope (oscilloscope) display of Voltage (V) versus Current (A),and the Signal Generator window which controls theer Amplifier. 文件將打開并帶一個(gè)電壓(V)電流(A)的示波器顯示和一個(gè)控制功率放大器的信號發(fā)生器窗口。Note: For quick reference, see the Experiment Notes window. To bring a display t

13、o the top,click on its window or select the name of the display from the lisof the Display. Change the Experiment Setup window by clicking on the Zoom box or the Restorebuttonhe upper righnd corner oft window.) 注意：如需快速參考，請參見實(shí)驗(yàn)注釋窗口。欲將一個(gè)顯示圖放至前臺，單擊其所在窗口或從顯示器底部的菜單欄中選擇該顯示圖的名稱。單擊窗口右上角的擴(kuò)大框或恢復(fù)按鈕來改變實(shí)驗(yàn)設(shè)置窗口的大小

14、。4.The Sampling Options_ for thiivity are: Periodic Samples = Fas4000 Hz (set inthe Scope display using the Sp Speed control).5.The Signal Generator is set to output 2.97 V, triangle AC Waveform, at 60.00 Hz. It is set to Auto so it will start automatically when you click REC or MON and stop automat

15、ically when you click STOP or PAUSE.信號發(fā)生器被設(shè)置為輸出2.97V，60Hz三相AC波形。它被設(shè)置為自動。因此當(dāng)你單擊REC或MON時(shí)，信號輸出將自動開始；當(dāng)你單擊停止或暫停時(shí)，信號輸出將自動停止。6.The Scope is set to show Output Voltage (OUT) on the vertical axis at 1.000 v/div and Current (A) on the horizontal axis at 0.100 v/div. 示波器被設(shè)置為以1.000 v/div的靈敏度在豎軸上顯示輸出電壓(OUT)，以0.1

16、00 v/div的靈敏度在橫軸上顯示輸出電流(A)。7.Arrange the Scope window and the Signal Generator window so you can see both of them.調(diào)整示波器窗口和信號發(fā)生器窗口的位置，以便你可以看到它們兩個(gè)。PART IIA: Sensor Calibration and Equipment Setup傳感器校準(zhǔn)和儀器設(shè)置You do not need to calibrate theer Amplifier.你無須校準(zhǔn)功率放大器。1.Place a ten ohm (10 _) resistorhe pair o

17、f component springs nearest to the banana jacksat the lower right corner of the AC/DC Electronics Lab circuit board.將一個(gè)10歐姆電阻器放入最靠近AC/DC電子學(xué)線路板右下角的香蕉插孔的那對組合式彈簧中。2.Connect banana plug patch cords from the output of theer Amplifier to the bananajacks on the AC/DC Electronics Lab circuit board. 將香蕉插頭接插線

18、從功率放大器的輸出端連接到的AC/DC電子學(xué)線路板上的香蕉插孔中。3.Turn on the關(guān)。er switch on the back of theer Amplifier. 打開功放背面的電源開(See the manual for a diagram.)（見手冊中的簡圖）Part IIIA: Data Recording Resistor (10 _)數(shù)據(jù)電阻器（10歐姆）1.Click the MON button to begonitoring data. Observe the Scope display of Voltage andCurrent. Adjust the ver

19、tical axis or the horizontal axis if nesary using the volts perdivibuttons. 單擊MON按鈕開始監(jiān)測數(shù)據(jù)。觀察電壓和電流的示波器顯示。必要，可使用volts per divi按鈕對豎軸和橫軸進(jìn)行調(diào)整。2.Observe the trace of voltage vs. current for a few seconds, then click the ST察電壓電流的軌跡幾秒鐘，然后單擊停止按鈕。utton.觀3.Turn off the關(guān)。er switch on the back of theer Amplifier

20、. 關(guān)掉功放背面的電源開4.Select the Scope window to make it active.選擇示波器窗口使之活動。YZING THE DATA Resistor (10 )分析數(shù)據(jù)1.Click the Smart Cursor buttonhe Scope. The cursor changes to a cross-hair. Move thecursoro the display area of the Scope. 單擊示波器中的靈敏光標(biāo)按鈕。光標(biāo)將變成一個(gè)。將光標(biāo)移到示波器顯示區(qū)。The Y-coordinate of the cursor/cross-hair

21、 is shown next to the Vertical Axis Input button:光標(biāo)/的Y坐標(biāo)將出現(xiàn)在豎軸輸入按鈕的附近：The X-coordinate of the cursor/cross-hair is shown next to the Horizontal Axis Input button:光標(biāo)/的X坐標(biāo)將出現(xiàn)在橫軸輸入按鈕的附近：2.Use the coordinates of a poon the trace on the Scope display to determine the slope ofthe trace on the Scope. Recor

22、d the value of the slope.用示波器顯示中軌跡上的一個(gè)點(diǎn)的坐標(biāo)來測定示波器上的軌跡的斜率。這個(gè)斜率的值。slope斜率 (10 _) = volts/ampsOPTIONAL選做1.Replace the 10 _ resistor with the 100 _ resistor. 用100歐姆電阻器替換10歐姆電阻器。2.Click the Increase Sp Speed buttonhe Scope display to change the sensitivity ofthe horizontal axis to 0.010 v/div. 單擊示波器顯示中的提高

23、掃描速度，將橫軸的靈敏度改為0.010 v/div。3.Repeat the experiment. Record the new slope.重復(fù)這個(gè)實(shí)驗(yàn)。新的斜率值。slope 斜率(100 _) = volts/ampsPROCEDURE B Light Bulb Filament步驟 B燈泡的燈絲PART IB: Computer Setup for Light Bulb Filament燈泡的燈絲的計(jì)算機(jī)設(shè)置For this part of the activity you will use the filament of a light bulb as the resistor.

24、Computer Setup you will change the Amplitude and Frequency of the output ACheWaveform. You will also change some of the settings on the Scope display.在這部分實(shí)驗(yàn)中，你將用一個(gè)燈泡的燈絲作為電阻器。在計(jì)算機(jī)設(shè)置中，你將改變輸出的AC波形的振幅和頻率。你也要改變示波器顯示的某些設(shè)置。1.Click the Signal Generator window to make it active.單擊信號發(fā)生器窗口使之活動。2.Click on the A

25、mplitude value to highlight it. Type in 2.5 as the new value. Press the “enter” key on the keyboard to record your change.單擊振幅值來加亮它。鍵入2.5作為新的振幅值。按下鍵盤上的“enter”鍵來你做的改變。3.Click on the Frequency value to highlight it. Type in 0.30 as the new value. Press the “enter” key on the keyboard to record your ch

26、ange. 單擊頻率值來加亮它。鍵入2.5作為新的頻率值。按下鍵盤上的“enter”鍵來你做的改變。4.Click the Scope display to make it active. 單擊示波器顯示使之活動。5.Click the Horizontal Input button. Use the Horizontal Inputto select Time Input(at the bottom of the list).單擊橫軸輸入按鈕。從橫軸輸入菜單中選擇時(shí)間輸入（在菜單的底部）。6.Repeatedly click the Decrease Sp Speed button unti

27、l the Sp Speed is 500.00ms/div.重復(fù)單擊降低掃描速度按鈕，直到掃描速度為500.00 ms/div。5.Click the Horizontal Input button again. Use the Horizontal Inputto selectogA (at the top of the list).再次單擊橫軸輸入按鈕。從橫軸輸入菜單中選擇模擬A（在菜單的頂部）。After making changes, the Scope display should be similar to the figure:修改完后，示波器顯示應(yīng)該象這個(gè)樣子：PART II

28、: Equipment Setup for Light Bulb Filament燈泡燈絲的儀器設(shè)置1.Remove the resistor from the component springs on the AC/DC Electronics Lab circuitboard.將電阻器從AC/DC電子學(xué)線路板上的組合式彈簧中取出。You will change the horizontal input from “og A” to “Time Input”, and then change the Sp Speed. Aftert, you will change the horizont

29、al input back to “og A”.你需要將橫軸輸入從“模擬A”改為“時(shí)間輸入”，然后改變掃描速度。然后，把橫軸輸入改回“模擬”A。2.Use two of the 10” wire leads to connect betn the component springs near the bananajacks and the component springs above and below 3 VOLT BULB “C”. 用兩根10引 線，將靠近香蕉插座的組合式彈簧和3 VOLT BULB “C”上面和下面的組合式彈簧連接起來。PART III: Data Recording Light Bulb Filament數(shù)據(jù)燈泡的燈絲1.Turn on the switch on the back of theer Amplifier. 打開功放背面的電源開關(guān)。2.Click the MON button to begonitoring data. Observe t