华科数字信号处理实验课作业报告.docx

1、华科数字信号处理实验课作业报告Digital Signal ProcessingExperiment ReportName: Student ID: Department: Data: 2014.12.15Experiment oneBridge performance testI. purposeLearn metal foil strain gauge strain effect works and performance ,comparing arm,half-bridge, full bridge sensitivity and non-linearity of output and

2、draw the appropriate conclusionsII. Materials1) Open sensor test box2) Strain Sensor3) Weights4) Cables5) MultimeterIII. Methods1.According to Figure 1,the wiring colors of resistance on the sensor strain gauges on R1,R2,R3 and R4 are yellow, white, red, blue. Use available multimeter to measure the

3、 two ends of the same color discrimination, R1 = R2 = R3 = R4 = 350.Figure 12.According to Figure 2 and Figure 3, access resistor300 into R24, R26, R27 ,then connect R1 into R25 on the board. If the wiring is correct, power it. Use a multimeter to measure the voltage between IN0 and IN1, adjust pote

4、ntiometer R28 (100R potentiometer), make the voltage difference between IN0 and IN1 to zero. we call this step the bridge zero. Figure 2Figure 33. The instrumentation amplifier circuit output terminal to the inverting input of scaling circuit, measured with a multimeter inverting output terminal of

5、the voltage scaling circuit. From the three former stage op amp amplifier, since R30 has been fixed, the amplification factor of the amplifier is determined by the R29 (1K potentiometer) when R29 tends to 0, the maximum amplification factor. Then the amplifier output voltage is about supply voltage

6、(potential difference depends on the polarity of the polarity IN0 and IN1s). To determine the specific amplification factor and avoid saturation of the amplifier output, where we can adjust to the top of the first R29 anti-clockwise, the resistance of about 1K ohms. So preamplifier its amplification

7、 factor of about 201. After scaling circuit level inverting its magnification by R40 (100K potentiometer) decided that in order to determine the proportion of the inverting amplifier specific amplification factor and avoid inverting amplifier proportion of saturated output, then we will adjust R40 c

8、ounterclockwise cut to the top. Its resistance is about 0 in Europe, after the level of magnification of approximately 1. Since we introduce the two-stage amplifier, when adjusting, increasing uncertainty. Consequently, in adjusting the beginning, we first pre-adjusted to the maximum of the potentio

9、meter, the potentiometer to adjust the subsequent stage to a minimum, fixed magnification levels.4. Note that R24 and R26 should force state the opposite, that the force sensor in two opposite (a tension, a pressure) as a resistance strain gauge bridge adjacent edges. Use a multimeter to measure the

10、 proportion of directly inverting amplifier circuit of the output voltage. Adjust R42 (10K potentiometer), the output voltage is zero, which we call the zero output.5. Wheatstone bridge performance test.100g weight is placed on the arm tray, see changes in the amount of voltage. If the voltage chang

11、e amount is very small, then the first clockwise adjustment potentiometer R40, post-stage amplifier circuit to change the gain (magnification). If you can change the amount of about 200mV. Note that, when changing the resistance R40, R42 of the resistance to be adjusted again, in order to meet the o

12、utput of the inverting amplifier circuit is zero proportional requirements. If you adjust the resistance R40, the output voltage variation still can not meet the requirements, the R40 clockwise to adjust to the top, and then adjust R29, the output voltage to the voltage change Claim. Note that, when

13、 changing the resistance R29, R42 of the resistance to be adjusted again, in order to meet the output of the inverting amplifier circuit is zero proportional requirements. After adjustment R29, R40 remains unchanged, with the experimental data to facilitate later comparison.3.Half-bridge performance

14、 testAccording instrumentation amplifier circuit diagram (Figure 1-2), the board will be R25, R27 access 350 resistor, the red strain sensor (or white) wire strain gauges connected into the circuit board R24 , the strain gauge yellow (or blue) line R26 connected to the access circuit board, then the

15、 strain R25 sheet R1, R3 and the circuit board, R27 connected as a differential DC bridge (half bridge). After checking the wiring is correct, power. Use a multimeter to measure the voltage between IN0 and IN1, adjust potentiometer R28 (100R potentiometer), the voltage difference between the IN0 and

16、 IN1 is zero.The rest follow as the above Experiment. Note that if you have to adjust the gain of the experiment a good tune, R29, R40 must remain unchanged.4. Full-bridge performance testAccording instrumentation amplifier circuit diagram (Figure 1-2), the strain gage sensors red, white cable acces

17、s board R24, R27, the strain gauge yellow, blue cable access R25 board, R26, form a full bridge circuit. After checking the wiring is correct, power. Use a multimeter to measure the voltage between IN0 and IN1, adjust potentiometer R28 (100R potentiometer), the voltage difference between the IN0 and

18、 IN1 is zero.The rest follow as the above Experiment. Note that if you have to adjust the gain of the experiment a good tune, R29, R40 must remain unchanged.IV. DataWeight is placed on the tray, inverting the read scaling circuit output voltage, increase the weight and successively read the correspo

19、nding voltage value. Write down the results to fill in Table 1 to 3, turn off the power.Table 1mass(g)0100200500The output voltage(V)5.9149.93515.11426.427 Table 2mass(g)050100150200300400500The output voltage(V)-7.794-5.4282.40912.06513.47630.10739.86756.884 Table 3mass(g)050100200500The output vol

20、tage(V)20.83735.54941.16966.796157.023V. Results & Discussion1. According to the Table 1 to 3 , draw changing graph of voltage and weight. 2. Calculate sensitivity S = V / M (ratio between output voltage variation and the amount of quality change).The three fitting equations is as follow:y = 0.041x

21、+ 6.131y = 0.130x - 9.948y = 0.273x + 17.868Therefore, S1 = 0.041, S2 = 0.130, S3 = 0.273Calculate the fitting error:error1 =0.0052499, error2 =0.01657, error3 = 0.34409The error is accepted since is small.VI. ConclusionCalculate the experimental sensitivity and compare experimental results.From the

22、 sensitivity we can find that sensitivity of wheatstone bridge is the smallest, and Full Bridge has the biggest sensitivity. So, the properity of Full Bridge is the best.Experiment teo-Photoelectric SensorsI. purposeUnderstand the principles and applications of photosensitive resistance and transmis

23、sion type photoelectric switchII. MaterialsOpen sensor test boxSensor breadboardDC ComponentsSeveral cableMultimeterLoggerIII. MethodsPhotoresistor1.Connect the light source circuit according to figure 1. Adjust the potentiometer and observe the brightness of the LED, and then cut off the power.Figu

24、re 1:Light source circuit2. Build the circuit on the sensor test box as shown in Figure 2.Check the wiring carefully to ensure it is correct. Then turn on the power.Figure 2: Photoresistor measurement circuit3. Adjust the potentiometer light circuit to change the LED brightness. Measure and record t

25、he output voltage value.Photoelectric switch1. Build the circuit on the sensor test box as shown in Figure 3.Check the wiring carefully to ensure it is correct.Figure 3: Photoelectric switch measurement circuit2. Turn on the motor switch and the motor drives the small flywheel. Adjust the speed knob

26、 to change the motor rotation speed.3.Collect and record the output signal.IV. Data1.PhotoresistorFigure 4: the waveform of the output with different lightnessFigure 5: the waveform after filtering2.Optoelectronic switchFigure 6:waveform of optoelectronic switchFigure 7: waveform of optoelectronic s

27、witch after filteringV. Results & Discussion According to the result of photoresistor experiment ,we can find that the stronger the light is ,the higher the output voltage is. We know that fs=5000, and the number of holes on the turntable is 12. According to the result of optoelectronic switch exper

28、iment, we can calculate the motor speed is 79.36r/min.VI. Conclusion Through this experiment we know the characteristics and application of photosensitive resistance. Our ability and analytical skills are exercised. Its a pity that we lost the data of resistance in the experiment of pholtresistor, s

29、o that we dont get the curve of the photosensitive resistances voltage change with resistance. This told us that it is important to preserve the data which we get from the experiment. Experiment three- K-type thermocouple Characteristics and Temperature MeasurementI. purpose Understand the temperatu

30、re characteristics and application of thermocouple.II. Materials1. Breadboard;2. K-type thermocouple;3. Operational amplifier OP07;4.1.3 K, 300 K resistance;5.33 K adjustable resistance;6. Several jumpers;7. Thermometer (bring your own) and heat.III. Methods1. Build the circuit shown in the figure 2

31、-1,carefully check the wiring, connect the thermocouple.Figure 2-1. Thermocouple Circuit2. Make the thermocouple close to the heat source, and adjust the potentiometer W1, to make the amplifier output voltage meet 10mV / . Adjust the heat temperature, repeated adjusting potentiometer to meet the requirements.3. Use Matlab to measure the voltage Vout and save the data.IV. DataUse Matlab to process the saved data, I get the result shown in figure 2-3, 2-4, 2-5. Their light intensity are enhanced one by one. Figure 2-3. Normal Atmospheric Temperature Figure 2-4. Hand