DOC PREVIEW
PSU PHYS 212 - The Oscilloscope & AC Circuits

This preview shows page 1-2-3-4 out of 12 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 12 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 12 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 12 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 12 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 12 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

The Oscilloscope & AC CircuitsSoftware ListEquipment List (all items marked with * are in the student kit, others are supplied at the time of the lab)Physics Lab 212P-10The Oscilloscope & AC CircuitsNAME: ____________________________________LAB PARTNERS: ________________________________________________________________________LAB SECTION: __________________________LAB INSTRUCTOR: __________________________DATE: __________________________EMAIL ADDRESS: __________________________Physics Lab 212P-10Software ListScience WorkshopMicrosoft ExcelEquipment List (all items marked with * are in the student kit, others are supplied at the time of the lab)RLC circuit boardOscilloscope + cableScience Workshop Interface + voltage probes*Connecting wires with alligator clips*Two 1.5 V batteries in holderLab Activity: The Oscilloscope and AC CircuitsThe oscilloscope is an extremely useful instrument for measuring electrical signals that vary withtime. The conventional oscilloscope is essentially like a TV set: it consists of an electron gun thataccelerates a beam of electrons towards a phosphor screen (say along the z-direction). The beamis deflected in the x-y plane by two sets of plates that provide an electric field. To measure avoltage that varies in a regular manner with time, we provide a periodic voltage to the x-platesthat "sweeps" the electron beam from one side of the phosphor screen to the other -- when itreaches the far right side, the beam snaps back to its starting position. Then, we provide themeasured voltage to the y-plates, so that the electron beam goes up and down, depending on thesupplied voltage. In this lab, you are provided with a Tektronix 2213 oscilloscope. The front panel of thisinstrument is divided up into six areas:- To the far left is the cathode ray tube (CRT) display.- The next vertical strip contains 6 items, including the power button.- The next two areas contain controls related to the vertical deflection of the electron beam(Channel 1 and Channel 2).- The last two areas on the right contain controls for the horizontal deflection of the electronbeam, including a time base control for determining the rate at which the electron beam willsweep across the display and the trigger controls for timing this sweep. Before turning the power on, check that the following knobs are in the indicated positions:1. Auto intensity: turn counterclockwise fully.2. The three "position" knobs -- Channel 1, channel 2 and horizontal -- pointing up.3. Vertical mode switches: Channel 14. Horizontal mode switch: no dly ("no delay")5. Sec/Div: 2 ms (2 millisecond/cm)6. Trigger mode: AutoNow, push the power switch on. Turn the "Auto Intensity" switch slowly counter clockwise. Youshould see a line appear on the screen. Keep the intensity at the minimum level required for youto clearly see the line. Prolonged operation at very high intensities can damage the phosphorscreen. If you do not see a line:- Check whether the scope is plugged in.- If the scope is plugged in, push the "beam find" button briefly. This should show you that thebeam is being deflected in a particularly direction but is off the screen. You can bring thebeam back by using the "position" knobs.Exercise 1: Using the oscilloscope as a DC voltmeter- Your scope should already have a co-axial cable connected to the "Ch 1" input. The redconnecting wire will be connected to the positive end of any voltage you want to measure,while the black connecting wire will be connected to the negative (ground) terminal. Ingeneral, it is important to keep to this convention to avoid potentially serious short circuits! - Note the red knob that is part of the "CH 1 Volts/div" control knob. Gently turn this red knobback and forth to get a feel for how it works. Then, turn it clockwise as far as it will go andmake sure that it clicks in place. The Channel 1 input is now "calibrated" so that the numberson the "volts/div" scale are meaningful! Anytime you use a scope, always check that thedifferent scale knobs are in the calibrated position!- Connect the red and black ends of the cable to each other to provide a clear input of "0" V.- Adjust the Ch 1 controls as follows:- Position: adjust this so that the horizontal line is in the center of the display.- Volts/div: set this to "1" on the 1X side (left side) of the dial. This means that every verticaldisplacement of 1 cm (major division on the display scale) corresponds to 1 V.- AC-GND-DC switch for CH 1: set this at DC.- Now connect a 1.5 V battery across the scope input, with the black connector to the"negative" terminal and the red connector to the "positive" terminal.- Note down the vertical deflection of the display line. Try to set the "volts/div" dial to a valuethat will give you the most accurate reading.- Repeat the above with the two batteries in series. Q1. Write down the readings you obtained above.Single battery: Volts/Div =Vertical deflection (cm) =Voltage (V) =Two batteries in series: Volts/Div =Vertical deflection (cm) =Voltage (V) =Exercise 2: Using the oscilloscope to measure the amplitude and frequency ofa periodic voltage signalNow, it's time to learn how the scope can be used to measure a voltage signal that varies withtime. We'll be using a signal that is provided by the Science Workshop interface box.- First, make sure that there is a pair of wires that are connected to the Science Workshopinterface box at the "output" banana plug outlets (extreme right).- Connect the scope leads to the output leads from the interface box, making sure you connectthe black lead to ground and the red one to the positive output.- Set the scope "CH 1 VOLTS/DIV" controls to measure 1 V/div. - Set the "Sec/div" knob to "5 ms." Make sure the central red knob is in the calibrated position.- Start "Science Workshop" and click on the "Sample V" icon. A window will open up thatallows you to select an output waveform with given amplitude (volts) and frequency (Hertz). - Set the amplitude to "1 Volt" and the frequency to "100 Hz."- Select the "sine wave" icon.- Click the "on" button.- Observe the oscilloscope display. You should see a sine wave. Discuss amongst your grouphow the pattern on the screen is quantitatively related to the frequency of the input signal.- Try turning the "sec/div" knob to different values and observe how the display changes. - Try varying the frequency of the Science Workshop output signal from 30 Hz to 300


View Full Document

PSU PHYS 212 - The Oscilloscope & AC Circuits

Download The Oscilloscope & AC Circuits
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view The Oscilloscope & AC Circuits and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view The Oscilloscope & AC Circuits 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?