mini project report

UNT Department of Electrical Engineering EENG 1910

Mini-Project Specifications

For your mini-project, you are to build an Astable Multivibrator Flashing LEDs circuit. A

kit containing the components necessary to build and solder the circuit will be provided.

The purpose of this project is to:

1. Learn how to build an electronic circuit.

2. Learn how to solder electronic components onto a breadboard.

3. Learn the building blocks of an Input-Processing-Output system.

4. Learn how to document the steps taken to accomplish the required activities and

report the lessons learned.

5. Practice presentation skills.

6. Practice technical report writing skills.

Together in class, each of you will build/solder their own circuit that you get to keep and

take home. Then, as a team you will:

1. Discuss and consolidate the lessons learned by each team member.

2. Discuss the importance of the project and how it relates to the items of the

project life cycle that we have discussed so far in class.

3. List the input, processing, and output components of the circuit.

Every functioning system has some input, processing and output component. Some

examples include: A computer uses keyboard or touch inputs, a processor to do

various computations, and a screen to display the results; A hydro-electric dam takes

water in, flows over a turbine (electric motor) and outputs AC current. A simple

diagram is shown below.

Figure 1. IPO system block diagram.

4. Explain how the circuit works, why the LEDs are flashing, and how to increase or

decrease the flashing frequency.

5. Brainstorm and propose an application for the circuit.

6. Simulate the circuit, experiment with the components, and propose an alternate

version of the circuit along with a suitable application.

UNT Department of Electrical Engineering EENG 1910

This circuit can be simulated by going to https://www.falstad.com/circuit/circuitjs.html

and:

1. Click on Circuits -> Transistors -> Multivibrators -> Astable Multivib to access

a built-in astable multivibrator circuit that you are to modify.

2. You will notice that the available circuit does not have LEDs or the proper

components.

3. Your goal is to insert LEDs into the circuit and update the value of the components

used – this is done by double-clicking the component and adjusting the associated

value.

4. To add an LED to the circuit, right-click on a blank spot on the design window ->

Outputs and Labels -> Add LED.

5. A wire can be added to connect components in the circuit by typing w on the

keyboard or right-click -> Add Wire.

6. Once the circuit is built, click Run/STOP on the right-hand side of the page to start

the simulation. The simulation speed and the current speed can also be

adjusted by using the scroll bars.

Note: Once you select a component to be added to the circuit, you will need to hit the

Esc button on the keyboard in order “to get your cursor back”.

There is a relation between the voltage (V) across a conductor, the resistance (R) of the

conductor, and the current (I) through the conductor that is referred to as the Ohm’s law

(this will be discussed later in the semester). According to Ohm’s law, V = R*I. If your

LEDs do not light up, one thing to check among others is to make sure the appropriate

current is being supplied.

In conclusion, your objectives are:

1. Build/solder the circuit individually.

2. Test the circuit and troubleshoot if necessary.

3. Write a report as a team that document your experiences, explain how the circuit

works, propose an application, simulate the circuit, and propose and

build/simulate an alternate circuit.

4. Make a presentation as a team.

There is a total of 200 points to obtain through this Mini-Project and up to 20 bonus points toward your assignment grade for any substantial additional feature(s) to the overall circuit/design.

• Presentation and Report: (100 points each) • Additional substantial feature(s) to the project: (20 points) • Due date: 10/02/2019