Design of Passive Filters, Diode and Diode Circuits - Lab Report Example

Electronic circuit Design Student’s Name College Instructor’s Name Course Name: Abstract The aim of this report is design, implement and analyse Passive Filters, diode and diode circuits using voltage drop across, current flow, resistance and temperature. The results show that diodes have a conducting ability when voltage is around 0.7V in the forward bias while in the reverse bias it allows little current through. The graph of the voltage across and its current is unique in all resisters as it begins to raise up at 0.7V. This is remains the voltage across the diode whether there is increase in input voltage. Thus there is a need to have resistor to be in series with the diode to limit current flow. The resistance of the diode is obtained by dividing the voltage across it by the current flowing through it as opposed to the value of the gradient. Table of Contents Title page …………………………………………………………………… 1 1.0 Abstract………………………………………………………………………. 2 2.0 Table of Contents…………………………………………………………….. 3 3.0 Introduction………………………………………………………………….. 4 4.0 Procedure……………………………………………………………………. 4 4.1 Passive Filters………………………………………………………. 4 High Pass circuit……………………………………………….. 4 Low Pass circuit……………………………………………….. 5 4.2 Diodes……………………………………………………………… 5 4.3 Diode Circuits………………………………………………………. 6 5.0 Results and discussion ……………………………………………………… 7 5.1 Passive Filters……………………………………………………… 7 5.2 Diodes……………………………………………………………… 14 5.3 Diode Circuits……………………………………………………… 18 6.0 Conclusion………………………………………………………………… 21 References…………………………………………………………………….. 22 Introduction The experiments are done specifically to ascertain how various connected units could be coordinated to give a more reliable and controllable functioning. It is from this understanding that this report is based in an attempt of communicating these findings. The experiment involves investigations of several parameters that are important for any industrial processing unit. Therefore, a slight change in these parameters could bring an effect on the current. How these changes could be coordinated to give a more desired aftermath was integral in this investigation. Of these is the output originating from the controller, its ability to coordinate with the desired power supply was investigated, how the current could be made more effective from the controller point of view was important. It was therefore mandatory when investigating this to apply control measures, and such effects of introducing any step changes on parameters like connection, the effects of integral actions on the system’s response was key too. The final part of the experiment involved communicating these findings based on performance characterization where graphical representation was important to clearly illustrate these findings. From these series of experiments it is clear that whenever there is an overlap in functional mechanism meant to regulate a functional parameter then the process would function at optimum if the it is regulated within the recommended range. This would also ensure other dependable functional parameter is highly maximized. For each of these experiments, the literature review, the underlying theory, the adopted methodology, the outcomes and their discussions and finally the derived conclusions have been illustrated as per the scope of work. Procedure Passive Filters i). Connect a resistor of 1kΩ and a capacitor of 22μF in breadboard as in the figure below ii). Connect 2V DC and measure the output using meter iii) Set E from the Function Generator as a sinusoidal at 1 MHz with 2 Vpp. Low pass filter i). Connect capacitor and resistor in breadboard ii). Draw a schematic of the circuit iii). Set vIN from the Function Generator to be 1sin(2πf.t). iv). Display on CH1 of the scope vIN and vOUT on CH2 for f = 10Hz Diodes 1. i). Fetch a 1N4148 forward bias the diode and 1kΩ resistor in series on your breadboard. ii). Connect them in series on breadboard and a DC input power supply voltages varying from 0 to 10V. iii). tabulate values for the voltage drop across the diode (VD) and the current through the diode (ID). iv). Draw a control graph of ID versus VD. v). change 1kΩ with a 3.3kΩ resistor, and plot a new ID versus VD on the same set of axes as above vi) Keeping the 3.3kΩ resistor in the circuit, reverse bias the diode. On a new set of axes, plot ID versus VD and comment on the nature of the plot. Diode Circuits i). Design and implement on your breadboard a half wave rectifier with an input sinusoidal voltage of 50Hz and 4Vpp, where the output is taken across a 680Ω resistor. ii) Display vin and vout on the oscilloscope iii) Measure the difference between the two peaks iv). Repeat the process but implement a clipper circuit v) Display the input and output waveforms of e) on the oscilloscope 3. i) draw the circuit below ii) Connect 4 1N4148 diodes, a load resistor of 1k_, function generator to be E = 10sin(21500t)V onto breadboards. iii) Use the oscilloscope to display E and vL. 1. Set both Channel 1 and Channel 2 to DC coupling 2. Enable the red trace, i.e. press the red MATH MENU button 3. Set the scope to display CH1 – CH2 4. Connect BNC-croc clip cables from both channels 5. Connect the black ends of the cables together 6. Set both channels to 5V/DIV 7. Connect the red cable from Channel 1 to the load between D1 and D2. 8. Connect the red cable from Channel 2 to the load between D3 and D4. f) Place a 220μF in parallel with the load, and observe the resulting effects. Results and discussion Passive Filters The value of the supply voltage frequency when E is a DC power supply of 2V f= = = = 7,238Hz or 7.238Kz The impedance value of the capacitor at this frequency XC = = = 1000 Z= = 1,414.31 A circuit that demonstrates the impact of this impedance The theoretical current value through the load I= = =1.414mA The theoretical voltage value across the load = IXL Theoretical voltage value across the load = 1.414mA1000 = 1414mV or 1.414V Actual theoretical Voltage 1.40 1.414 At this frequency what is the impedance value of the capacitor? XC = = = 7.234 A circuit that demonstrates the impact of this impedance The theoretical current value through the capacitor I= = =0.277A The theoretical voltage value across the load = IXL Theoretical voltage value across the capacitor = 0.277A1000 = 277V Actual theoretical Voltage 275 277 2. Designing a Low Pass circuit The schematic of the Low Pass circuit Varying the frequency from 10 Hz to 100 kHz and a sketch of the frequency response, and deduce the cut-off frequency from it. The formulae for gain of the circuit in decibels Decibels(dB)= 20log10 Gain = = = 1sin(2πf.t). Sketch the Bode Diagram in your lab books for the gain in decibels and for the phase in degrees for f ranging from 10 Hz to 100 kHz. F(Hz) ( 20log10 10 482.53 53.67 20 241.27 47.65 40 120.63 41.63 80 60.32 35.61 200 24.13 27.65 400 12.06 21.63 500 9.65 19.69 1000 4.83 13.67 2000 2.41 7.65 5000 0.97 -0.31 10000 0.48 -6.33 20000 0.24 -12.35 40000 0.12 -18.37 80000 0.06 -24.39 100000 0.05 -26.33 At cut-off frequency of 1kHz the value of the gain in dB -2.33 dB At the cut off frequency of 1kHz the value of the phase in degrees and in radians is 4000o and 400rad/s The circuit above and draw in your lab books an equivalent circuit for low frequencies and another for high frequencies. This is low pass filter Implement the above circuit on your breadboard, with C = 1μF and R = 1kΩ. Theoretical cut off frequency = = = 1 kHz Varying the frequency from 10 Hz to 100 kHz and sketching the frequency response of the circuit. Bode Diagram for the gain and for the phase for f ranging from 10 Hz to 100 kHz. At cut-off frequency of 1kHz the value of the gain in dB -13.05 dB At the cut off frequency of 1kHz the value of the phase in degrees and in radians is 1000o and 300rad/s Diodes 1. i) Fetch a 1N4148 diode is silicon semiconductor material Connecting with the 1kΩ resister as follows; Tabulation values for the voltage drop across the diode (VD) and the current through the diode (ID). Input DC voltage Diode Voltage(1k) current through the diode(1k) Diode Voltage(3.3k) current through the diode(3.3k) 0.0 V 0 0 0 0 0.2 V 0 0 0 0 0.7 V 0.61 1.7 0.61 1.7 1.0 V 0.62 2.5 0.62 2.5 1.6 V 0.64 3.7 0.64 3.7 3V 0.67 7.9 0.67 7.9 4 V 0.7 16.4 0.7 16.4 5 V 1.76 2.77 1.76 2.77 7v 1.81 5.88 1.81 5.88 10V 1.88 11.69 1.88 11.69 A control graph of ID versus VD They both have a conducting voltage 0.7 V and the voltage drop across a diode stays at this value for further increases in the current Diodes become conducting at about 0.7 V and the voltage drop across a diode stays at this value for further increases in the current. Any voltage is increased beyond 0.7V then A resistor required to hold the excess voltage. The 3.3kΩ resistor in the circuit, reverse bias the diode and plot ID versus VD From the graph Forward Biased Region v > 0, Reversed Biased Region v < 0 and breakdown Region v < -VZK If the temperature at the diode increases by 10°C diagram of the change in the forward bias characteristic with the 3.3kΩ to change. At a constant current, the voltage drop decreases by approximately 20 mV for every 10°C increase in temperature. Since the reverse leakage current doubles for every 100 C increase. The static resistance at the Q-point 2. a) For the above circuit, tabulate varying values of V1 from 0 to 10V, I and VD12 . VD 2 VD2 V (V) I (mA) V (V) I (mA) 0.49 0.00 0.49 0.0 0.51 0.0 0.51 0.0 0.53 0.0 0.53 0.0 0.54 0.0 0.54 0.0 0.7 0.48 0.7 0.48 0.73 0.06 0.73 0.06 0.76 0.13 0.76 0.13 1.08 0.20 1.08 0.20 1.39 0.28 1.39 0.28 1.60 0.49 1.60 0.49 1.61 0.55 1.61 0.55 1.73 0.86 1.73 0.86 1.84 1.10 1.84 1.10 1.87 1.70 1.87 1.70 Plot ID versus VD12 and comment on the results. It clear that the current flow in both diodes is limited to 0.7V no current flows through the diode. As the voltage increases For V1 = 7V, verify Kirchhoff’s Voltage Law for this circuit. Tabulate varying values of V1 from 0 to 10V, I and VD123 total voltage drop across all diodes). The total voltage across the diodes is zero. In this a current flows through first diode while the third and second diode there is no flow of current since the third diode is reverse biased. The voltage across the D2 is limited to the voltage across the D3 as it is reverse biased. Diode Circuits Design and implement on your breadboard a half wave rectifier with an input sinusoidal voltage of 50Hz and 4Vpp, where the output is taken across a 680Ω resistor. Input and output waveforms, assuming that rD >> R The voltage across the resistor- When the input voltage age is negative, the output voltage vR is zero, so the negative half of the “wave” has been cut off. a capacitor inserted to smooth the output voltage. the dark graph line shows the voltage across the resistor, assuming the RC time constant is much larger than the period of the sinusoidal input voltage. The light graph line shows what the output would have been without the capacitor. Normal Diodes VD= 0.7v are used for rectifier of input of much larger amplitude then VD. For smaller signals detection, demodulation or rectification Operational Amplifiersare used Conclusion The experiment successfully determined the calculated values of current that were in close proximity with the values of RC in the sample test records provided. The graph plotted comparing the experimentally determined and the sample values pursued a linear path which also confirmed the success of the experiment. The Inverse Square Law was successfully established in the experiment as the linearity of the obtained curve in Graphs was as expected due to the inverse variation of the area of the transfer intensity with the square of the distance from the centre of the source of power. This is the reason why the shape of the log curve tends to follow an inverse straight line. References Crowe, J. & Hayes-Gill, B. 1998. Introduction to Digital Electronics. London: Butterworth-Heinemann. Dale, RP & Fardo SW, 2009. Industrial process control systems. Boca Raton: Fairmont press, Inc. Forsthoffer, W. F., (2006). Rotating Equipment Handbooks: Principles of Rotating Equipment. Manchester: Elsevier. Giambattista, A., Richardson, B. & Richardson R, 2007. College Physics. Boston: McGraw Hill. Holdsworth, B., 2000. Digital Logic Design. London: Doctronics Educational Publishing for Design & Technology Lewin, DR, Seider WD & Seade, JD 2005. Integrated Process, Design Instruction: Computers and Chemical Engineering. Cache News. Mondie, S. 2005.System, Structure And Control. Oxford: Elsevier-IFAC. Nilsson, J. & Riedel, S., 2010. Electric Circuits. New York: Prentice Hall Serway R, & Jewett J, 2008. Physics for Scientists and Engineers/With Modern Physics. Sydney: Thompson Brooks/Cole Shah, LS & MacGregor, FJ., 2005.Dynamics and Control of Process Systems. Oxford: Elsevier Smith, KC & Sedra AS. 2009. Microelectronic Circuits. Oxford: Oxford University Press. Read More