The following information is a single lesson in a larger project. Find more great projects here.

Project Overview:

In this course you will learn about some more components and circuit layouts which make electronic devices work, like series and parallel circuits, buzzers, sensors, and a new electrode design. At the end of the course you will make your own pressure-activated alarm system.

## Step 1: Introduction

In this course you will learn about some of the components and circuit layouts that make electronic devices work.

We call it "Making Circuit Magic" because circuits can seem mysterious, but the flow of current through electrical circuits does make sense! First you will create your own paper pushbutton, then learn about buzzers, series and parallel circuits, sensors, and square waves. Finally, you will use your new tools to create a pressure-activated alarm system!

1. Press the "next" button below to continue.

## Step 2: Looking Inside a Button

You have probably seen buttons on a lot of electronic devices. Even the keys on your computer keyboard are buttons!

What do they look like inside?

A simple button has two terminals that are separated by a gap in the center. When you push the button, a conductive material gets lowered onto the gap and completes the circuit.

This conductive material can be a plunger, a strip, a film, or some other shape.

In the next step you will make your own button!

1. Press the "next" button below to continue.

## Step 3: Making a Simple Button

Take a look at the first circuit in the Workplane.

When a conductive material is placed between the gap in the circuit electrodes, the circuit is completed and the light comes on. However, you have to make sure that you are touching both pads with the conductive material. The material has to be long enough to span the outlined gap between pads and you have to aim for this small area.

1. Press the "next" button below to continue.

## Step 4: Making a Button With Fingers

The second circuit is a little more complex. The six lines are called fingers and they interlock like the fingers of your hands!

This circuit works the same way as the first, but you can place a conductive material anywhere inside the marked square instead of aiming for the two separated circles.

1. Press the "next" button below to continue.

## Step 5: Constructing a Paper Button (part 1)

In this step, you will use the circuit templates to make your own paper pushbuttons with Circuit Scribe.

First, you will print out the templates and draw over them with Circuit Scribe ink. The circuit with finger electrodes is shown in the picture below.

1. Print out the circuit template by clicking the "Download PDF" button and printing the pdf from your browser.
2. Trace the template in between the dotted black lines with the Circuit Scribe pen.
3. Place your circuits on a magnetic surface, and place the battery and LED modules over their outlined areas.
4. Press the "next" button below to continue.

## Step 6: Constructing a Paper Button (part 2)

Next you will create the conductive strip that pushes down to complete the circuit.

You'll make that using a piece of construction paper with an area of Circuit Scribe ink on one side.

1. Cut out a piece of construction paper, at least 2 cm on either side. It can be any shape you want!
2. Draw a 2 cm circle with the Circuit Scribe pen and fill it in.
3. Press the "next" button below to continue.

## Step 7: Constructing a Paper Button (part 3)

Now it's time to operate the button!

Flip the paper strip ink-side-down and press it over the gap in each circuit.

Which one is easier to operate -- the button with two separated circles or the button with finger electrodes?

1. Flip the construction paper strip upside down and place it over the gap in each circuit.
2. Press down on the paper strip and watch the LED light up.
3. Which button is easier to operate?
4. Press the "next" button below to continue.

## Step 8: What Did You Observe?

1) We always have to apply pressure to the construction paper in order to make a good button connection.

2) The button with finger electrodes was easier to press. We could use one finger to operate the LED.

3) The two-circle button was more difficult. We had to apply pressure over both of the pads using two fingers.

In the rest of your time remaining, try using the conductive pen in the simulator to make a finger electrode with a bigger area!

You will get to use a finger electrode in the final project - a pressure activated alarm.

1. Operate both button circuits using the paper pushbutton.
2. In your time remaining, draw your own circuit with a finger electrode. Practice using the virtual Circuit Scribe pen to create different patterns.

In the next lesson you will learn about circuits in series

Next Lesson:What's the Buzz on Series Circuits?