Whether you’re a beginner or a more advanced maker in electronics, a breadboard is a great solution for prototyping electronic circuits. They are popular due to their durability and ability to make quick connections.
Breadboards are plastic slabs with grids of holes in them that allow users to insert electronic components onto them. By inserting components onto them in a certain arrangement, a circuit can easily be built!
We’ll be looking at the layout of the breadboard and what parts are interconnected.
Here we have an overhead view of a breadboard.
Each individual column that is highlighted in green is made up of holes. Holes that are in the same column are electrically connected. So a component will be connected to anything else placed in that column. This is because there are metal strips within the breadboard that allow current to flow from any point in that column.
You’ll also notice that there is a space in between the top group of columns and the bottom group. This space highlighted in yellow is called the ravine of the breadboard and it isolates both the top and bottom sets of columns so that they are not connected.
We may want to connect a power source to our circuit in order to power components all along the breadboard. How can we do this? That’s where the rails of the breadboard come in!
First we have the positive rails which are highlighted in red. You’ll notice that these are different from the terminal strips in that these are connected horizontally instead of vertically. This means that for each positive rail, all the holes are electrically connected. Its important to note that each positive rail is isolated from each other, so the top positive rail is not to connected in any way to the bottom one.
Just as we have our positive rails, we also have our negative rails. These are highlighted in blue and are horizontally connected just as the positive rails are. It’s important to note that the top negative rail is not connected to the bottom one.
How to Use a Breadboard
Components can be inserted into the holes of the breadboard to electronically connect them to each other. Lets look at an example of how we can use a breadboard to create an actual working circuit.
LED Example Circuit
To show the usage of a breadboard, we’ll be creating the a simple LED circuit where an LED runs off a 3.7V battery through a current limiting resistor.
Here is a schematic view.
Here is a breadboard diagram of the circuit.
And here it is created on an actual breadboard. Lets see what’s going here:
The positive terminal of the battery is connected to the positive rail of the breadboard.
The positive rail of the breadboard is connected to the right side of the resistor through a jumper wire connected to the same terminal strip.
The left leg of the resistor is connected to the positive leg of the LED through the same terminal strip.
The negative leg of the LED is connected to the negative rail of the breadboard by a jumper wire.
The negative rail of the breadboard is connected to the negative terminal of the battery.
Adding ICs and Modules
It may happen where we would like to work with microcontrollers, modules, and DIP (Dual Inline Pin) components by placing them onto our breadboard.
This is is the L293d DIP integrated circuit chip that is commonly used for operating small motors. Components such as these can be easily used for prototyping as they are breadboard compatible!
Here we see a microcontroller (left), a DIP IC (center), and a pushbutton (right) that are placed onto the breadboard. These components with many pins make use of the breadboard’s ravine. As we learned earlier, the ravine isolates the top and bottom sets of terminal strips. This allows pins connected to the top set to not interfere with pins connected to the bottom set so we can use are complex components without worrying about a short circuit!
Note: The components shown above can be placed onto the breadboard by pushing them gently into the breadboard until each pin occupies a single terminal strip hole. When removing them from the breadboard, do so carefully to not bend or break the pins of these types of components.