L1 - This is lab 1 of 6 - Lab For Eece 2210 PDF

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This is lab 1 of 6...

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Northeastern University Department of Electrical and Computer Engineering

EECE 2211: Lab for EECE 2210 Electrical Engineering Lecturer: Prof. Masoud Rostami TAs: Linbin Chen Kan Yao Amine Belkessam

Lab #1: Basic Components and Circuits. Group #22: Richard Duchin

Semester: Fall 2016 Lab Session: Thursday, 2:50-4:50PM

Lab Location: 9 Hayden Hall, Northeastern University, Boston, MA 02115

Content

Page

1. Introduction / Objective

3

2. Approach / Procedure and Results

4

3. Conclusion

7

Introduction The overall objective of this lab was to experiment with a variety of different devices that together produce the foundation of electrical components used in the course. Through the use of resistors, meters, diodes and function generators, experiments were conducted to understand how they operate. More importantly, how current and voltage flow through various different circuits. This lab was also purposed to help brush up on breadboard operation and actually building physical circuits.

Approach/Procedure & Results To perform this laboratory procedure, it is required that we both a small and large breadboard, a digital multimeter, a series of resistors, both variable and standard, diodes and LEDs, and a voltage/current source. To begin the lab, we take a measurement of the resistance for a 1kOhm resistor to test its tolerance and reliability. The measured resistance was around 990 Ohms, which is partly due to its tolerance and its use over time. Over time resistors lose their potency and therefore show lower resistance values.

When adding them in series the

expected equivalent resistance is 2kOhms, however the experimental results yielded a 1.85kOhm. When the resistors were put into parallel the expected equivalent resistance should be 1/R1+1/R2 or 200ohms. The experimental result was 230ohms, which is to be expected due to resistor tolerance.

The next step was to actually assemble a DC circuit. Using a voltage source and a 1kOhm resistor a simple circuit was constructed.

Figure 1: Parallel resistor circuit Another resistor was added in parallel and the current across the resistors was calculated. The current should be equal in both resistors because they are both connected to the source.

Next the resistors were connected in series and the voltages were taken across both resistors as well as each.

Figure 2. Series resistor circuit. After this was observed, the two resistors were disconnected from one another and the voltage was recorded across each resistor.

Next an Low current diode was configured in series with a 1kOhm resistor and a 5V source.

Finally the LED is swapped with the LCD and we calculate the resistance required to be 1 kOhms for this experiment if we have 20mA of current and a voltage drop of 2V over the LED. After trying the LED in both direction we determine the correct orientation, where the positive terminal is the longer lead.

In the second portion of the experiment we utilize a function generator to learn about AC circuits. By setting up the circuit as seen below we can see how different wave forms affect a circuit.

By producing a 10 Hz square wave with +\-5 Volts, otherwise a 10V peak-to-peak amplitude we can analyze how the led is affected. As we manipulated the frequency between 100hz and 0.5hz, the speed at which the LEDs turn on and off varied. The higher the frequency the faster it flickered. The two LED’s should light up at different times because of the time it takes for the wave to reach that portion of the circuit. The two LED’s will be in different phases. The highest frequency we could see was about 60Hz.

Conclusion This lab served the purpose of introducing some of the basics of circuits and some of the applications. Through the use of a function LED’s, resistors and a function generator we learn how voltage resistance and current are affected when certain components are configured in

different ways. This lab has created the foundation of knowledge that will allow for more successful understanding further along in the course as the concepts get more advanced....