How do breadboards work?


What is a breadboard?

A breadboard is a device for building electronic circuits. How do breadboards work exactly?

They are a plastic pin board of holes that are interconnected with metal strips underneath the surface. In a row each five pins are connected together, these are usually labelled a-e. Then there is a break in the middle and the next five pins are connected together and usually labelled f-j. These identical rows run down the board and are usually labelled 1-63. The holes are spaced 0.1 inch apart, the same as for IC’s.

A typical breadboard

how do breadboards work - breadboard

Running down the side are four buss bars. Two on the right and two on the left, sometimes these are coloured red and blue to aid in polarity as these are almost always used to supply the power to the circuit. It’s also worth noting that on some breadboards there is a break in the middle of each which you need to bridge if you want continuous power all the way along.

The picture below shows a breadboard with which holes are connected shown in yellow.

how do breadboards work connected holes

The beauty of this device is that it is a solderless method of construction and therefore very quick and easy. Beginners can learn to use breadboards in a matter of minutes as there are very few techniques to master and you can have simple circuits up and running in a few minutes. It’s like Lego for electronics.

Electronic components are inserted into the board and linked with other components and wires where necessary to build the required circuit. It is a temporary method of construction and although used by beginners they are also very useful for more experienced constructors to try out stuff. You can take a finished circuit and then reconstruct it on Vero board for a more permanent solution after you have verified the circuit does what you want, also freeing up the breadboard again.

When using a bread board ensure that the component leads are clean. If they aren’t not only could you get a bad or intermittent connection but the dirt can get inside the metal strips of the breadboard. Also be careful if the components are supplied on a strip with tape. Cut them off with side cutters instead of pulling them off so you don’t leave any sticky residue on them which will transfer to the internal strip of the breadboard causing all sorts of problems.

When using wires to connect to the breadboard you should use single core cable not the multicore twisted variety. Individual strands can break off and get into the breadboard. It’s also a lot easier to insert the solid core wires. If you’re making your own connecting wires the best thickness is 22AWG. If the wire is too thin it will bend as you try to push it into the breadboard and wire that’s too thick can damage the internal connections of the breadboard.

When you strip back the cable you should expose around 5mm as that’s about how deep the contact area is. It will give you the best hold in the socket as it can be pushed all the way down to the bottom. You don’t want a connection only just in as it’s easy to dislodge it as more connections are added. Trying to find where a wire has come from is no fun at all.

If you don’t want to mess around with making interconnecting wires, you can buy packs especially for breadboards they have plug connections on each end. They come in various colours and lengths and are reusable and when you see how cheap they are you’ll probably wonder why you bothered making them in the first place.

65 Pcs Assorted Length Multicolored Flexible Solderless Breadboard Jumper Wires

If you are making a particularly complicated circuit and you have lots of interconnections you may be better off making your own links out of single core wire as you can make them to exactly the right length. There will usually be several short straight connections that suit doing this and it does make a tidier finished circuit. As you can see from the picture below it makes connections easier to follow.

how do breadboards work short connections

That is a basic answer for the question of how do breadboards work? If you are looking for more information you can go on to the next part which is more specifically about practically building circuits on breadboards from circuit diagrams and is called how to build a circuit on a breadboard.