Physics 3150/5190 Electronics Lab Manual …

1 Physics 3150/5190 ElectronicsLab ManualUniversity of VirginiaFall 2012-VVerrVsInstructor: Cass SackettCONTENTSCONTENTSC ontents1 Test and Measurement ELVIS .. Power Supplies .. Virtual DMM .. Measuring Current .. Ohm s Law .. Violating Ohm s Law .. Electrical Safety .. Resistor Properties .. Oscilloscope and Function Generator .. Triggering Options .. RC Circuit .. Transformer .. Reporting .. 112 Impedance and Transfer Voltage Divider .. Cascading Circuits .. DMM Impedance .. RC Filter .. Bode Analyzer .. Filtering Signals .. Cascaded Filter .. Scope Impedance .. 163 Current vs. Voltage .. Diode Drop .. Power Diodes .. Rectifiers .. Filtering and Ripple .. Zener Diodes .. Diode Clamps .. 214 IV Relations .. Transistor Switch .. Emitter Follower .. Common-Emitter Amplifier.

2 Field Effect Transistors .. FET Switch .. FET Follower .. 311 CONTENTSCONTENTS5 Op Amps Installation .. Open-Loop Test .. Inverting Amplifier .. Non-inverting Amplifier .. Follower .. Summing Amplifier .. Current Sources .. Current to Voltage Converter .. Logarithmic Amplifier .. 386 Op Amps Output Capacity .. Offset Voltage .. Bias Current .. Johnson Noise .. Slew Rate .. Frequency Response .. Integrator .. Differentiator .. 447 Feedback and LED Driver .. Photodiode .. Summing Amplifier and Set Point .. System Response .. Feedback .. Servo Performance .. Servo Analysis .. 508 Feedback and Control Proportional Control .. Integral Control .. PI Control .. PID Control .. Transient Response .. 579 Logic Transistor Gates .. Integrated Gates.

3 Logic Families .. CMOS Logic .. Combinatorial Logic .. Three-State Logic .. Multiplexer .. Monostable Multivibrator .. Logic Races .. 6710 Flip-Flops, Memory, and State D-type Flip Flop .. State Machines .. Switch Debouncing .. RAM .. Memory-Based State Machine .. 7511 Counters and Binary Counter .. LED Display .. Binary-Coded Decimal .. Timer .. Quartz Crystal Oscillators .. 8012 Converting Between digital and Comparator .. Schmitt Trigger .. The AD7569 DAC/ADC .. Negative Supply .. DAC .. ADC .. Nyquist Sampling Theorem .. 8713 The mbed Microcontroller .. digital Inputs and Outputs .. Arbitrary Waveform Generator .. LCD Display .. Voltmeter .. Communication with PC .. Multi-Channel Analyzer .. Wrap Up .. 97A Excel Creating a Chart .. Modifying a Chart .. Fitting Data.

4 Excel 2007 .. 9931 TEST AND MEASUREMENT TOOLS1 Test and Measurement ToolsThis exercise is intended to familiarize you with the measurement tools we will be usingthroughout the course, specifically the ELVIS system, the digital multimeter, and the oscil-loscope. It also serves to remind you how resistors and capacitors lab will require two : HH sections , Appendix A (pgs. 1 28, 1045 1049) ELVISWe will be doing most of our work on the NI ELVIS II system, which consists of a bread-board, several built-in interfaces to the computer, and a set of software tools running on thecomputer that duplicate the functions of some common test a moment to orient yourself with the board. The large white square in the middleis the breadboard proper, where you will set up your circuits by pressing leads into thesmall holes. The numbered rows are connected internally in horizontal groups of five, whilethe + and - buses are connected vertically down the whole board.

5 Note that anothermanufacturer s breadboard might be connected differently, even if they look the same. Itis always a good idea to check which contacts are connected when working with a newbreadboard. Let us do that now with the ELVIS convenient instrument for this purpose is the Fluke 73 III digital Multimeter (DMM).The DMM can measure voltages, currents and resistances. Here we will be interested inresistance, so turn the selector knob the DMM to the resistance ( ) setting. Plug a pair oftest probes into the red (V- -diode) input and the black (COM) inputs of the DMM. Use apair of short hook-up wires from your wire box to reach two contacts you want to check, andthen hook the leads of the DMM to the exposed ends of the wires. The resistance shouldbe zero if the contacts are connected, or infinite (reading for overload) if they are the contacts are connected as described above? Are the different columns labeled + connected together?

6 The smaller white rectangles on the edges are interface connections. Each row is hookedup to a device that can interact with the computer, or to one of the connectors on the edgeof the board. We will often use the block in the lower left corner, which provides access tothe built-in power supplies and connectors on the left edge of the box itself are measurement inputs to the virtualDMM and and oscilloscope. The knobs on the right side of the box allow Manual adjustmentof some of the virtual instruments, but we will not often have occasion to use them. Thecontact blocks on the right side of the breadboard are for digital measurements, which wewill use in the second half of the board has two power switches. The one in the back controls the whole unit. It iseasiest to turn this switch on at the beginning of class and leave it on throughout the labsession. The second switch, near the upper right corner of the board, controls the powersupplies for your circuitry.

7 It is best to turn that off when assembling a circuit and thenturn it on for testing, to avoid damaging circuit components during Power Supplies1 TEST AND MEASUREMENT Power SuppliesThe ELVIS breadboard has several dc power supplies. Locate the +5 V and 15 V supplycontacts on the breadboard. To verify that they do supply these voltages, use the voltmeterfunction on your DMM. Turn the selector knob to the dc volts ( V) setting. Keep the probesin the red and black inputs, and hook the red probe to the supply contact and the blackprobe to ground. (Note that there are several ground connections on the board; they are allthe same.) The display will indicate the measured voltage. Record each in your report, andnote any discrepancies from also has a pair of variable-voltage supplies that will be useful. They are controlledfrom the computer. First, find the ELVIS Instrument Launcher icon on the desktop or StartMenu. Start the Launcher and then double-click to start the Variable Power Supply (VPS)virtual instrument.

8 In the resulting window, set the positive supply output to 10 V andpress Run. Then locate the positive VPS contact on the breadboard and measure its voltage(again relative to ground); you should see 10 V. Similarly, set the negative supply to -10V and check it. Measure both supplies across a full range of values, and make a chart inyour report showing the measured vs. set voltages. How accurate are the VPS set points?Are there any voltage regions where the accuracy is poor? (Hint: the answer to the secondquestion is yes, and it will be useful for you to know where these regions are.) Virtual DMMThe ELVIS system provides a virtual DMM you can use in addition to the Fluke. To startit, run the DMM instrument from the launcher and press Run in the DMM window. Theinput connections are located on the left side of the ELVIS box, and you can use them tohook up probe leads just like on the Fluke. Compare the readings of the Fluke and theELVIS DMMs for various settings on the VPS supplies.

9 Record your measurements in yourreport. How well do the Fluke DMM and ELVIS DMM agree? Measuring CurrentThe DMM can also serve as a current meter. To test this, set up the circuit of Fig. , usingthe Fluke DMM inputs indicated. You can obtain the 1 k resistor from the componentcabinets in the back of the lab. Note that when using a DMM as a current meter, it is up toyou to make sure that the current rating (here 300 mA) is not exceeded. If you do exceedthe limit, you will blow an internal fuse and have to fix up the circuit and measure the current that flows. The DMM selector knob shouldbe set to dc amps ( A). Make the same measurement with the ELVIS DMM. How well tothe Fluke and ELVIS DMMs agree? Ohm s LawDevise and set up a circuit to simultaneously measure the voltage and current across a 1 k resistor, and describe the circuit in your lab report. Take several points and create a Violating Ohm s Law1 TEST AND MEASUREMENT TOOLS300 mACOMF igure : Using the DMM current verify thatV=IR.

10 How does the resistance obtained from your data compare to thatmeasured with the DMM ohmmeter?Instead of taking data like this by hand, you can use the ELVIS two-wire IV Analyzerinstrument. Put a resistor between the DUT+ and DUT- contacts, near the top of the lowerleft block. (Here DUT stands for Device Under Test. ) Open up the 2-wire instrument andset the sweep to run from -10 V to +10 V, with a sensible increment. Press Run and admirethe nice straight line. To transfer the data to your report, first save the data by pressingthe Log button. Pick a file name and save it on the desktop or in a convenient folder. Thenopen the file using Notepad (or a similar program) and cut and paste the data into yourExcel report. Add this data as a new series to the chart you previously made by hand Violating Ohm s LawMany devices do not follow Ohm s Law, including an ordinary incandescent lamp. Obtaintwo V/150 mA lamps from the supply cabinet.