Lab report Diode, oscilloscope and function generator PDF

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Summary

The following laboratory report examines the characteristics of diode to help students create suitable rectifiers circuits....

Description

Ohm’s Law

Course Name: Introduction to Electric Equipment and Components Semester and Year: Fall 2020 Name of Student:

Name of Lab Instructor:

Date of Report Submitted:

Grade:

Abstract The main objective of this lab experiment is studying the characteristic of the diode. By understanding the characteristics of the experiment, rectifier circuits can be implemented using a diode. The experiment was performed using a combination of resistors and single diode to create half-wave rectifier in addition to using a function generator. In the second part of the experiment, AC – DC property of diode were determined using multimeter, and a capacitor.

Objective and Introduction The main objective of this lab experiment is investigating the characteristics of the diode. Particularly, the characteristics that will be examined in the experiment include rectification and I-V curve properties of the diode. After completing the experiment, the curve of the diode will be able to be compared with the experimental data. In addition to that, I-V characteristics of the diode will be plotted with the curve tracer. Furthermore, be able to construct filtering and rectifier circuit utilizing capacitor and diode. A diode is an electrical gadget that is capable of allowing electricity to flow with ease in one direction compared to the other direction. A diode is gadget made from a semi-conductor material with p-type and n-type junction. The lead that is connected to the n-type material is the cathode and the p-type material the anode. The main function of the diode is rectification. When the higher potential has been connected to the anode, diode becomes forward bias, enabling current to pass. However, when the higher potential is connected to the cathode, it becomes reverse biased, blocking current from passing.

Theory and Experimental Methods Typical designs of the diode circuit used in modern electrical devices are semiconductor diode, despite existence of other technologies. The symbol for diode is illustrated in Fig.1 as shown below.

Fig.

1

Semiconductor

Diode,

(2017),

[Online

Image],

Retrieved

from:

http://www.datwiki.net/page.php?id=7031&find=semiconductor %20diode&searching=yes. Diodes are utilized in circuit where AC current and voltage are converted to DC current and voltage, for instance ac/dc power supply. Diodes are also preferred in voltage limiting circuits, voltage-shifting circuits, voltage regulator circuits, and voltage multiplier circuits (Alonso-Garcia, Ruiz, & Chenlo, 2006, p. 073102.). In Half-Wave Rectifier, ac input voltage on the diode is converted to the pulsed dc output voltage. In the latter circuits, the diode block the current when it tries to move negative at the diode, in this manner making the output voltage to shift to zero. In AC-DC converter, a bridge rectifier and transformer are used to construct ac to dc power supply (Kiameh, 2003,). The voltage of circuit is stepped down with a transformer, while the bridge rectifier changes the ac input to pulsed dc output. The out pulses can be smoothed with a filter capacitor by discharging the time. A larger capacitor

is used for providing enough energy thus maintain constant current supply to the load (Zhang et al., 2006, p. 330). Part of the experiment involved the setup of the Half-wave rectifier. A combination of resistor with one diode was used in the setup of part one of the experiment. 2 Vpp input signal and 60 Hz without offset were used to create the halfwave rectifier. The function generator was set to 0 offset and 1Vpp. R = 1k was used for the experiment. Caution was taken while using the function setting of the generator. The output and resistance were connected carefully to avoid making it burn. Multimeter was used to measure the threshold voltage in the experiment. The threshold voltages of the diode are measured from the scope. It was achieved by measuring the difference between the peak of the output signal and the input signal The second part of the experiment entailed determining AC-DC characteristics of the diode semiconductor. The rectifier from the first part of the experiment is used for converting AC voltage to DC voltage. AC-DC converter was setup as shown in Fig. 1 below. The same input from part one were used in the setup shown in Fig. 1 below. R =1M and C=22uF was used in the setup of the experiment,

RESULTS AND DISCUSSION The voltage across the diode was established to 0.0488 (V) and voltage from scope was 0.8 (V). In both experiment, a current of 1=0.63 (mA) was used in the experiment. Using the equation below, the value obtained from the experiment were computed. In addition to that the polarity of the voltage applied influence the polarity dependent, which is a characteristic of I-V. The negative terminal, of the experimented was established to acquire majority carrier, including holes contained in the positive terminal as well as the p-regions. At this regions, the terminal attract electron by pulling them toward the n-regions further away from the junction. As a result, the charge carrier close to the junctions minimizes while at the depletion regions near the width increases. Furthermore, the current that flow is small in amount because of the impact of minority carrier, termed as leakage current or bias current. Conclusion From the experiment, when the forward biasing voltage was exceeded, the voltage of the diode was constant. Furthermore, it was established that the negative and positive pulses were absorbed when the forward-biasing voltage was surpassed. From the experiment, how to measure and compute diode characteristics were learnt.

References Alonso-Garcia, M. C., Ruiz, J. M., & Chenlo, F. (2006). Experimental study of mismatch and shading effects in the I–V characteristic of a photovoltaic module. Solar Energy Materials and Solar Cells, 90(3), 329-340. Kiameh, P. (2003). Electrical Equipment Handbook: Troubleshooting and Maintenance: Troubleshooting and Maintenance. McGraw Hill Professional, p.4 Zhang, Z. Y., Jin, C. H., Liang, X. L., Chen, Q., & Peng, L. M. (2006). Current-voltage characteristics and parameter retrieval of semiconducting nanowires. Applied physics letters, 88(7), 073102.

APPENDIX A. Calculation Vripple = I load /fC V = 0.63/ 60 Hz x 22 uF V= 0.4773 x 10 -4 ∆ v=

I 2 fc

∆ v=

0.63 x 10 −6 = 2 x 60 x 22 x 10

−3

(V)

B. This work (experiment) has been carried out by: Student name

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