Physics 115 Electronics and Instrumentation …

1 Physics 115 Electronics and InstrumentationLaboratory ManualDr. William Updated:July 112 Table of I: Basic DC II: Basic AC III: IV: Transistors and Voltage V: Operational VI: Instrumentation Amplifiers and VII: Introduction to VIII: digital Aside: Intro X:LabVIEWDAQ A: Parts A: Parts B: Resistor C: Operational D: Common Data are a part of every modern laboratory. Physics , chemistry, biology,and geology all utilize electronic devices to measure and record various you need to measure temperature, light intensity, magnetic fields, humidity,charged particles, time, or strain, all can be measured using readily available goal of this course is not to turn you into an Electronics whiz.

2 Rather, it is asurvey course that will introduce you to the broad range of electronic devices andtechniques that are commonly used in laboratories today. While we will spend some timeon historical and fundamental devices, such as transistors and A/D chips, we will focusmost of our attention on practical and useful devices: op amps, computer-integrated dataacquisition cards, and specialized integrated circuits (ICs). Our goal is to instill in you adegree of comfort and familiarity with Electronics that will be useful in designingexperiments, building simple circuits, and understanding the behavior ofcomplexcircuits. By the end of the semester you should be comfortable in developing computer-controlled data systems where you have conditioned the signal of interest using yournewfound electronic skills and collect the data on the computer using theLabVIEW software have chosen not to include much theory in this manual .

3 First of all, all of theinformation would be repetitious because the same information will be in your textbookand/or lecture notes. Second of all, I ve tried to prevent this manual from being a self-contained cookbook. Forcing you to use your notes and textbook will, in the end, makeyou more experiments will take a single session, others will take two. They are,however, all equally theLabVIEW software package is commonly encountered in researchand industrial laboratories,there is a recommended text in the bookstore that teaches thedetails of it. We also have a couple of copies of theLabVIEW text in the lab to manual will also likely serve as a reference for future classwork, particularlyin Physics 116, Advanced Electronics and Instrumentation .

4 I suggest that if you areplanning on taking this course, you hold onto this is thesixtheditionof thismanual;it is mainly for correcting some errors andrestructuring some experiments. It is only available electronically; it is not for sale in general, the Electronics that one encounters in this class are no more dangerousthan those one may encounter upon replacing a 9-V battery in a household electronicdevice; most Electronics textbooks do not even discuss safety hazards. In fact, the biggestrisk to ones health in this class is mechanical rather than electrical:dropping aninstrument or computer on your , one must still be careful to avoid exceeding tolerances on all resistors can get very hot very fast and can leave a blister on one s fingersif touched.

5 Transistors are famous for popping when improperly wired. The shrapnelfrom one could scratch the cornea of your eye; an experience that your contact lenswearing friends will assure you does not feel good. While we don t normally solder inthis class, if you find that youneed to, make sure youusea pair of safety glassesSoldering flux or molten solder would be very unpleasant in an eye (as Dr. DeGraffenreidcan attest to).However, one should not take a cavalier attitude towards aremany cases one will encounter in the laboratory where high voltages are a part of theexperiment. Care needs to be taken in such a case; a current of a few milliamperesthrough your heart can cause severe problems.

6 If you find yourself workingon highvoltages, it is a good practice to have your arm grounded so that if you touch the highvoltage with your hand, the current won t cross through your fact, it is a good practice to use grounding straps at all times when workingwith Electronics . This is not necessary for your own safety, but rather for the safety ofthe devices you are working with; static discharge can be deadly for many semiconductordevices. Unfortunately, we don t have grounding straps to go around. Luckily, we usegenerally inexpensive components. If you find yourself using high-end components inyour final project, please ask about borrowing a grounding strip to InstrumentsMultimetersWe will normally usebenchtopdigital multimeters (DMM)in this course, although wedo have someanalog andhandheld digitalmultimeters available if needed.

7 The theorybehind multimeters, particularly analogmetersis very interestingbut,unfortunately,wedon t have time to cover it in this course. If youare interested in finding out moreinformation regarding them, refer to your textbook. There are two models ofbenchtopKeithley multimeters that we will commonly use in the lab: the Model2000 and theModel 179(A).The Keithley Model 2000will be our primary instrument, butformeasurementswewill also need to use the 179(A). The Tektronix Model #2236 Oscilloscope also hasa built in multimeter that we mightoccasionally use for DC specifications of theprimarymeters are listed below:Model 2000 Model 179 ADigits6 4 V 1 kV10 V V 750 V10 V kVDCA10 nA 3 A10 nA 20 AACA1 A 3 A10 nA 20 A 100 120 M 100 m 20 M Frequency3 Hz 500 kHz NA InputImpedanceDC G 1 M AC1 M 1 M Clearly the Model2000 is a more precise instrument.

8 It can also be computer interfacedvia GPIB if desired. Its main drawback is its complexity. For most purposes 6 digitsis overkill and just slows down the refresh rate. From the front panel you can decreasethe number of digits displayed. The Model 2000 can only measure currents up to3amperes, whereas the Model 179A can go up to 20 amperes. This isn t usually aconcern in this course where we usually work with currents less than 1 ampere. Severalcopies of theModel 2000user smanual are available for review and it is also available inpdf format on the Electronics Laboratory Resource analog multimeters are the Triplett 630-NS. The Tripplett meters can be used tomeasure AC and DC voltages and DC currents.

9 While the controls for the Tripplettmeters indicateresistance can be measured, we no longer keep batteries in these metersthat are required to power the resistance youmake connections,you should use theV Aand common inputs (unless you are measuring currentshigher than A, in which case you use the 12A input and the common).6 OscilloscopeThe most widely used instrument in the lab is probably the oscilloscope. In this lab, wewill be using the Tektronix Model 2236. This is a fairly advanced analog scope with anumber of useful features, including a built in period/frequency also have aclassroom set of Tektronix Model TDS1002 scopesand two high end scopes: theTDS3044 Band the will only be used sporadically in 115; while the digitalscopes are have somewhat more power and flexibility, they can also be misleading if youare not familiar with the basics of making measurements with an analog alldigital scopes areavailable on the Electronics Laboratory Resource exactoperation of oscilloscopes varieswidely, the most important elements ofthe front end are basically unchanged.

10 While your textbook has a brief section describingthe operation and use of oscilloscopes, I would also like to refer you to The XYZ s ofOscilloscopes, published by Tektronix (one of the leading oscilloscope manufacturers).There are several copies of this available for use in the classroom and is also availableinpdf formatonthe Electronics Laboratory Resource suggest that you read thismanual before using the Lives! The most common tool in 115 is the National Instruments ELVIS workstation. These workstations integrate a breadboard (prototyping board), powersupplies, waveform generators, and computer interface into a single can be controlled via the workstation s front panel or by software on thecomputers; we will generally use the front the Electronics LaboratoryResource Page for the ELVIS User s convenient way to design and troubleshoot a new circuit is to first design it on a breadboard.