# DE Unit 1: Circuit Theory

An introduction to calculation, simulation, and building with simple circuits## CIRCUIT THEORY OVERVIEW

The study of digital electronics is all about electric circuits, and how signals of on/off (1/0) can be turned into complex logic. Many devices around us run on digital electronics – the classroom clock, the fire alarm, many digital clocks, microwaves, etc. When digital engineers tackle problems in digital electronics, they need to focus on the following process:

- Define the Problem
- Calculate and Design a Solution
- Simulate the Solution
- Breadboard the Solution
- Test & Evaluate
- Communicate Results

Not surprisingly, the task of digital engineers follows a path very similar to the engineering design process we’re used to. The biggest difference is that the digital electronic process requires more mathematics and simulation. In this first unit we’ll get an introduction to the process by doing three big things:

- STEP 1: Learn the basics of simple circuits and practice the calculations that go along with digital electronics
- STEP 2: Get an introduction to our computer simulation and the practice of breadboarding circuits
- STEP 3: Build a small digital project by following a kit to solder a working random number generator as “digital dice”

When you’re done, you will have seen the whole digital electronics process and built a small project. Don’t worry, the questions about the little details will be answered throughout our year’s class!

**PART 1: CIRCUIT BASICS**

*(20 pts) About 3 days*

Start by investigating basic circuits and the tools of digital electronics. Here you’ll get to learn the names of major electronic components and practice the fundamentals of mathematics as it relates to the study of digital electronics.

**PART 2: SIMULATE & BREADBOARD**

*(30 pts) About 3 days*

In this second part of the unit, you’ll be asked to start learning a new software: Multisim. This simulation software is used by professional engineers to build electronic circuits in the computer. You’ll then get to create a physical model of your circuit by breadboarding.

**PART 3: BUILD A PROJECT!**

*(20 pts) About 3 days*

In the last part of the unit you’ll be given the tools and instructions to build a working electronic system. This system uses basic electricity to randomize numbers and show the result as the display of a die. A cool application of digital electronics!

# Part 1: Circuit Basics

Learn the components, tools, and calculations that make digital electronics possibleThe beginning of our class starts with the the very basics of circuit design. In this part of the unit, you’ll spend a day building some simple circuits with lights and a breadboard by following some clear instructions. After that, you’ll get to investigate the kinds of components we’ll work with, and then do some simple calculations for resistance, voltage, and current. These ideas will start very simple, but as the year progresses they’ll be an essential part of the work we do!

**GRADING & PROCESS**

Watch the video on Basic Circuits and take a full page of careful notes.

Build the 2 basic circuits and answer the short reflection questions in your notebook

Watch the video on Analog Components and add to your previous page of notes. Be sure to look through the Analog Component Reference!

Watch the video on Hand Calculations and make sure to write down good notes about Ohm’s Law, and Total Resistance in parallel and series circuits

Complete the Electronics Calculations Assignment

Have Mr. Benshoof approve your notes and completed Assignment

Basic Circuits

Analog Components

Hand Calculations

**What’s Due** In *Part 1: Circuit Basics*

- Circuit Notes
- Basic Circuits
- Component Notes
- Resistor Assignment
- Calculation Notes
- Calculations Assignment
- Mr. Benshoof’ Confirmation

Here’s what’s due in Part 1: Circuit Basics

- Watch the video on Basic Circuits and take a full page of careful notes.
- Build the 2 basic circuits and and answer the short reflection questions
- Watch the video on Analog Components and add to your previous page of notes. Be sure to look through the Analog Component Reference!
- Complete the Resistor Identification Assignment
- Watch the video on Hand Calculations and make sure to write down good notes about Ohm’s Law, and Total Resistance in parallel and series circuits
- Complete the Electronics Calculations Assignment
- Have Mr. Benshoof confirm your notes and assignment!

# Part 2: Simulate & Breadboard

Build some basic circuits in Multisim and on the DMS BreadboardDigital engineers need to be fluent in the use of mathematics for hand calculations, simulation with computer software like Multisim, as well as breadboarding circuits. By being good at all three of those tasks, engineers can make systems more efficient or create systems that do brand new things. In this part of the unit you’ll get to focus on two key skills: simulation and breadboarding!

**GRADING & PROCESS**

Watch the presentation on getting started in Multisim, and take a page of good notes!

Complete the practice circuits and measurements in Multisim, print 3 circuits and tape them into your notebook, adding additional notes around them

Watch the presentation on breadboarding and take a page of good notes

Build all 4 circuits in the breadboarding activity

Measure and record the voltages and resistances requested for each of the 7 circuits

Have Mr. Benshoof check-off each simulation and breadboarded circuit as they are completed

Getting Started in Multisim

Breadboarding Basics

Breadboarding Walk-Through

**What’s Due** In *Part 2: Simulate & Breadboard*

- Multisim Notes
- Multisim Circuits
- Breadboard Notes
- Breadboard Circuits
- Circuit Measurements
- Benshoof’s Check-off

Here’s what’s due in Part 2: Simulate & Breadboard

- Notes on the Getting Started in Multisim presentation
- Building all 3 circuits in Multisim
- Notes on the Breadboarding Basics presentation
- Building all 4 circuits on your DMS breadboard
- Recording the needed measurements from all 7 circuits
- Have Mr. Benshoof check-off your completed circuits and measurements

# Part 3: Build a Project!

See all the parts in action as you build some “Digital Dice” from a kitThe last part of our introduction focuses on the assembly of a digital project. Digital Electronics engineers work hard to calculate, simulate, design, and eventually build circuits of all kinds. In this part of the unit you’ll get to do the building part as you organize, assemble, and solder a working electronic circuit. For now we’ll just be following the instructions printed on a circuit board, but as we keep working the way that this system functions will be explained.

**GRADING & PROCESS**

Watch the video on building your Digital Dice

Collect all the needed components by following the materials guide, and find where they each belong on the circuit board

Assemble and build your Digital Dice! Be sure to watch the How To Solder video before soldering

Sketch your completed Digital Dice board in your engineering notebook; label as many components as you can

Have Mr. Benshoof confirm your working Digital Dice & sketch

Digital Dice Overview

How To Solder

Troubleshooting

**What’s Due** In *Part 3: Build a Project!*

- Build Digital Dice
- Sketch Digital Dice
- Mr. Benshoof’s Confirmation

Here’s what’s due in Part 3: Build a Project!

- Build your Digital Dice by following the instructions and using the right components in the right orientation!
- Make a careful sketch of your completed Digital Dice in your engineering notebook, labeling as many components as you can
- Have Mr. Benshoof confirm your working Digital Dice & sketch

# Double Check: Unit Expectations

Check what you need to have completed by the unit deadlineThe purpose of this unit is to give you a 3-week whirlwind tour of all things digital electronic. At times, this unit will feel very hectic, but the goal really is just to introduce all the basic ideas that we’ll address later in the year. In this unit you should see: basic circuits, simple circuit calculations, beginning simulations, breadboarding, and soldering. To keep it all fun, you even get to build a working device. You will likely end this unit with more questions than you started with, but that’s largely the point. Have fun, and know that the answers to all your questions will be answered in this class!

**Engineering Notebook:**

(Part 1) You should have taken a full page of notes on ** basic circuits** and

**.**

*analog components* (Part 1) You should have taken a full page of notes on ** Ohm’s Law** and

*Total Resistance* (Part 2) You should have taken good notes on both ** breadboarding** and

**.**

*Multisim* (Part 3) You should have ** drawn and labeled** a diagram of your working Digital Dice.

**Building & Making:**

(Part 1) You should have built the ** 2 basic circuits** and confirmed that they work.

(Part 1) You should have completed the *Hand Calculations Assignment*

(Part 2) You should have simulated ** 3 circuits in Multisim** and found the corresponding measurements

(Part 2) You should have ** breadboarded the 4 simple circuits** and found the corresponding measurements

(Part 3) You should have built your ** Digital Dice**!

**Checkpoints & Quizzes:**

(Part 1) Benshoof should have checked-off your ** notes **and your

*Hand Calculations Assignment* (Part 2) Benshoof should have seen and approved** all 7 of your different circuits** as well as the measurements you were supposed to take from each

(Part 3) Benshoof should have confirmed your working ** Digital Dice**.