Electronic Circuit Basics with TinkerCAD
TinkerCAD is a free online service for creating basic 3D shapes and developing digital prototypes of electronic components. It can be used on most devices that run Windows, Mac OS X, and Chrome. Tinkercad can also be used on tablet devices like iPad and most Android tablets. These prototypes include basic circuits with LED lights, buzzers, switches and even temperature sensors. The electronic prototypes can include a microprocessor. Microprocessors are the simplest form of computer that can be programmed to manipulate electronic components like LED lights and buzzers. Microprocessors can be programmed to gather information from senosors and interpret that information with can be sent to output components like buzzers or LEDs. Microprocessors are used in a variety of devices all around us. They are in microwaves, refrigerators, cars, computers and many other electronic devices.
The process used in TinkerCAD is one often used for rapid prototyping. Prototyping is a process where we can develop components in a flexible manner than can be quickly updated and modified to test a variety of options when developing a project or product. We will use this process of prototyping to learn how to create basic electronic circuits. In this lesson we will learn how to create a basic closed circuit with an LED light.
The first thing we will do is go over to https://tinkercad.com and create a free account. Tinkercad integrates with Social Media services like Facebook. It also Integrates with services like Microsoft and Google. Students can use their district accounts to log into Tinkercad with their district account.
Go to the left side of the page after logging in and click the circuits menu option.
Click on the button to create a new circuit.
The circuit project is created and opened. A circuit project includes a variety of electronic components. Electronic components include LEDs, buttons, resistors, and a power source.
The components we can use are displayed in a panel at the bottom of the page.
Components are commonly assembled using a Breadboard. A Breadboard is a piece of plastic that has several holes. These holes are used to hold different components. Find the Breadboard component and click on it once.
The Breadboard will be selected and temporarily attached to the mouse pointer. Move the mouse pointer onto the workspace and click the mouse button to place the Breadboard onto the workspace.
The Breadboard might appear too small or too large in the work area. Click on the zoom to fit button so the Breadboard is centered and magnified.
The Breadboard has a grid of thirty by ten holes in the main area. The rows are numbered 1 to 30 and the columns are labeled with the letters A through J. The columns A through E are separated from the columns F through J by a piece of plastic.
The edges of the board contain two columns with the same number of rows. These columns have negative and positive symbols. These columns and holes are used for our power supply. The components in the center part of the board will tap into these columns to draw electrical current.
Move your mouse pointer over one of the holes in the center part of the board. The hole beneath the selected hole will be identified with a red square and a black border. The other holes will be identified with green circles. These green circles indicate that each hole in the row is connected to each other hole in the row. There is a connecting wire linking any connection within the same row. We will use this linking to help develop circuits.
Closed Circuit with An LED
Our first project will create a basic closed circuit with a light. Our light will be supplied by an LED. Click on the Components button to open the components drawer if it isn’t already open.
Click on the LED component. It will attach itself to the mouse pointer.
Place the LED onto the board so that each lead of the LED is in a hole. A Lead is a wire that connects two locations of a component electronically.
An LED has connections that make it different from a regular light bulb. An LED has one connection called a Cathode and another called an Anode. The Anode lead is usually longer than the cathode. This distinction is important because the anode must be connected to the positive end of an electric circuit.
The LED anode in our circuit is identified by a bent lead. This is where the positive current must connect.
We need a power source to power the LED. Open the components panel and find a battery. We will use the AA battery with 1.5 volts for our first example. Place the battery along the left side of the Breadboard.
Click the active components button to close the components panel.
We can zoom in and out of our project using the scroll wheel on our mouse or touch gestures on a track pad, but that can be difficult. It might be easier to use these short cut key combinations. If you are on a Windows or Chromebook computer, hold the Control key and press the Plus key to zoom in or the Minus key to zoom out. An a Mac computer, hold the Command key and use the Plus to zoom in or the minus to zoom out. Tap the plus or minus key a couple of times instead of pressing and holding one of these keys.
Zoom out of the project so you can see the battery along side the Breadboard.
The terminals for the battery are at right angles to the Breadboard connectors. Battery terminals are the negative and positive connections. The terminals in this example, are pointing up.
I find it useful for the terminals to be parallel to the connectors. We can rotate the battery so the terminals are parallel. Click the battery once to make sure it is selected. A blue border appears around selected components.
Click the rotate button in the button bar. This will rotate the component clockwise in small increments of about 30 degrees each. Click the button three times to rotate the battery 90 degrees clockwise.
The terminals should be facing the Breadboard.
We need to connect the battery to the Breadboard so it supplies current to our LED. We connect components to one another with Lead wires or Jumper wires. These are wires coated with a plastic and exposed ends that can be used to jump from one component to another. This is one reason they are called jumper wires.
Move your mouse pointer over the top terminal. A square will appear over the terminal and a label will appear identifying the terminal as the negative battery terminal.
Click once on the terminal and move the mouse pointer to the first hole in the negative column. Click once on the hole to complete the connection. This is how we create lead or jumper wire connections. All the other holes in the negative column are identified with a green circle. This means that all these holes are connected and can be used to connect the negative end of wires or components.
Repeat the process with the positive terminal and place the lead wire onto the positive hole on the breadboard. When a connection is complete the ends of the wire will be identified with circles.
This is a simple circuit with only a few wires but circuits can get complicated very quickly with many wires jumping from one location to another. It is usually a good idea to identify these wires with colors. There are some standard colors that are used in electronics. Red is usually used for positive connections and black for negative connections. The wires in these connections are green. In homes, green is usually used to identify ground wires. We can color code our wires.
Make sure the positive terminal wire is still selected. A Breadboard wire configuration panel is located on the right side of the page. Click on the color selector.
Select the red color.
Repeat the process for the negative terminal wire and change the wire color to black.
One of the benefits of using a Breadboard is that components can be easily moved around to form new connections or to make room for other components. Click and drag the LED to column f.
The LED will light up when we have a closed circuit. This circuit isn’t closed yet. We need two wires to close the circuit. One wire for the positive and one for negative. The positive current must flow through the anode in our LED. Click on Row 4 Column J to begin our jumper wire. Connect the other end of the wire to the positive column.
Connect another wire from Row 3 Column J to the negative terminal column.
Our circuit is now complete. We should change the color or our wires so they match the polarities.
In the simulation, nothing happens until we run the simulation. Click the Start Simulation button.
The LED on the Breadboard will change to a lighter color to simulate the LED has turned on.