## Introduction: Breadboard Basics for Absolute Beginners

The aim of this instructable is not to give you a complete guide on breadboard but to show the basics, and once these basics are learned you pretty much know all you need to so i guess you could call it a complete guide but in a different sense. Anyway i will only be using an led and some resistors to outline how a breadboard works.

Note : a breadboard is a temporary circuit board for testing and prototyping circuits, no soldering is done on the board, this mean it is faster and easier to prototype circuits.

Also if you need a walk through on electronics please read my other instructable A Complete Guide To Basic Electronics
anyway onto the supplies!

## Step 1: Supplies

For this instructable you will need
an led
a 4aa (or aaa) battery pack
a few 100ohm resistors (or any value but you will need to change your layout to get the same results)
and finally a multimeter (measures voltage, resistance, current ect.)
Once you have these you are good to go

As you can see from the image below a breadboard has lots of holes, this may seem confusing at first but it really isnt. The 2 rows of holes at either end are for power one for positive (red) one for negative (black).
as you can see i edited the picture below to give you an idea of how circuits are completed.
the power strips go horizontally in 5's where as the component strips go vertically also in 5's.
a circuit is completed when all the desired strips form a loop and are all connected sequentially.

if for instance i wanted to put an led in this circuit by its self i would insert one leg into a free hole of the column where the black (-ve) power jumper is and the other in a free hole of the column that the red wire (+ve) is in. This would complete the circuit allowing current to flow from one side of the power source to the other through the led.

The green lines in the image below form a series circuit where every component touches at different polarities (-ve leg of one component to +ve leg of another) . The forms a single chain of components.
A parallel circuit in this would be that the components you desire to be in parallel would touch at the same polarity (-ve leg to -ve and +ve leg to +ve). so as two colums are needed to accommodate any component with two legs in parallel these components would share the same columns but be in separate holes. if this made no sense dont worry, i will go into more detail later.

## Step 3: The Conductive Layout

as per the image you should see the layout of most breadboards, in rows for the power and columns for components.
not much more i can say here really.

## Step 4: Adding Power and Jumpers

Now its time to start placing things onto the breadboard. The first thing attach is the power, simple put the negative lead into one hole and positive into the other (doesn't matter which really). Then place jumpers on the board to bridge the gap between the power rows and the component columns.

## Step 5: Resistors

For the purpose of this instructable i will only be connecting one led to a 6v source and use resistors to protect the led from burning up. i have some 100ohm resistors lying around that will be perfect for this project.

For resistors in series their values always add, meaning 2 100ohm resistors in series would give a total resistance of 200 ohm however in parallel this is not the case.

In parallel the value of resistors decrease the more you add . If using the same value resistors then the equation is simple

value of one resistor / number of resistors e.g. 5x100ohm in parralel = 100 / 5 - 20ohms total resistance.

however if using resistors with varying values this equation is easier (this equation can be used in the upper example but it is faster when using the same value resistors to use the above method)

ok so say i have a 10ohm, 100ohm and 30ohm resistors in parallel. (in series these would give a total resistance of 140ohms).

1/rt = 1/r1 + 1/r2 + 1/r3 ect.. (this can go on for however many resistors you have)
rt is the total resistance and r1 and r2 ect. are resistors, so for our example we will use this

1/10 + 1/100 + 1/30 =1/rt
0.1433= 1/rt so 1/0.1433 = rt
rt = 7ohms (rounded)

ok so now we know the basics of resistors in circuits we can start working out how many we will need to power this led

## Step 6: The Led and Resistors Needed to Protect It

The led i am using today is a bright blue led. this led runs on 3.3v and at 20ma (milli amps).
the power pack i'm using is 4aa batteries. with each battery being 1.5v that gives a total of 6v
however i don't want my led to be getting the whole 6v and that would burn it up and cause it to heat up. I don't even need the full brightness so for the purpose of this instructable i will be running the led at 3v 20ma.

so so how do we get 3v and 20ma from a 6v source. its simple, use resistors. how many depends on a number of things.
the supply voltage
the voltage rating of the component (for us its 3v)
and the current you want across the component. (for us its 20ma)

the equation is simple voltage = current x resistance or v=ir
we can rearange this to get resistance = voltage / current or R = V / I
however the value of v in this case is the voltage we need to drop from the supply to get 3 v.
so v = Vsupply - Vled = 6-3 = 3volts
and we know the current needs to be 20ma so the final equasion is as follows.

R = 3 / 0.02 (or 20x10 to the power of 3)
R = 150 ohms
(this equation is pictured below on my dusty calculator)

now we know the resistance needed lets move onto the circuit

## Step 7: Parallel Resistors

Right so we need 150ohms of resistance but we only have 100ohm resistors.
now here is where out knowledge on parallel circuits comes in handy.
ok so if we use a 100ohm resistors in series thats 100ohms taken care of but we still need to muster up another 50ohms.
remember in in previous sections i said this
"In parallel the value of resistors decrease the more you add . "
and seing as we have the same value resistors we can use this equation also stated previously
value of one resistor / number of resistors

so in order to get 50ohms we can use 2 100ohms resistors in parallel.
100/2 = 50
simple!

100 (resistor in series) + 50 (2x100 in parallel) = 150ohms total resistance!, so were set to put the circuit together now.

the picture below shows two of out 100ohm resistors in parallel. as you can see they are sharing a column with common polarity (doesn't matter with resistors though).

as you may also see one leg of each is connected to the -ve end of the power source. this is the first step to completing our circuit

now onto adding the series resistors, simple place one leg into the same column as the left most leg of the resistors and the other leg into the hole next to it. (also pictured below)

ok so onto adding the led now!

## Step 8: Adding the Led

now we need to place our led into the circuit. As you may have noticed from step 5 an led has a short leg and a long leg. she short one connects to the -ve end of the power source and obviously the longer leg to the +ve end. this is because an led allows electrons to flow easily from the cathode(-ve) to the anode(+ve) but not from the anode to the cathode, so if your led doesn't light always first inspect the polarity of the led.
now all you need to do it place the short leg into the same column as the left most left most leg of the series resistor and the other leg into the column that the posotive power jumper is in.
you should now see the led light up and in my case hurt your eyes and you were looking right into it.

not done yet though!
onto testing the circuit

## Step 9: Testing the Voltage Across the Led

now using out multimeter we need to take the voltage across the led to ensure the circuit is operating correctly and we didnt make any errors when calculating the resistance.

! important a voltmeter has infinite resistance (basically it breaks a circuit) so it is always used in parallel !

so to take the voltage simply turn the multimeter to a suitable voltage setting and touch the black probe to the short led (closest to the -ve (black)) and the red probe to the other led (if you put them the other way round you will get a -ve voltage)

3.05volts, id say that is acceptable seing as my resistor has a tolerance of 5% (+ or - 0.15)

now to test current

## Step 10: Testing Current

Now we set out multimeter to current (for me i had to change the position of the red lead into the 10a hole)

unlike voltmeters ammeters run in series, as the current does not change through out the circuit, therefore it doesn't matter where the ammeter is in the circuit it will always give the same reading.

to test the current flow i simply moved the led +ve leg right one hole (stoping the led from lighting as the circuit isnt complete until my probes are in place)
and then place the black probe on the +ve leg of the led and the red probe onto the jumper coming from the +ve end of the power source, this completes the circuit. illuminating the led and displaying the current. which is in my case 20milliamps, exactly what i was after.

so thats it, you should know know how to use a breadboard. and if anyof this didnt make sense or you want to recommend how i can improve this instructable please leave a comment
thanks alot!

triumphman (author)2017-05-16

This is great, but you need to show better placement of resistors and LED. A bird's eye view would really be helpful. Thanks for this !

Troymako (author)2017-03-23

I have been working with a breadboard for a year and a half now, so I am a bit embarrassed to ask this. I am thinking of getting a breadboard with screw on power supplying (i.e. Va, Vb, Gnd). I do not know if these screw-ons are connected to any of the holes. I.e. by screwing a power source ground to the ground bolt will all of the ground holes be grounded.

2 battery version with a switch

Thanks a ton for helping me make my first DC circuit!

RahulS337 (author)2016-06-19

thank you very much! Dint xpect ny professionals to expain the very basics of such projects.... and that too with such a patience.... Thank You once again....\\ :)

Zem (author)2009-06-11

Is a breadboard different than a circuit board? And is so, how?

zaneg3 (author)2016-04-05

Yes, though only in practicality as functionally they are the same. A breadboard is used to prototype a circuit in an easily re-designable manner before implementing it into something more permanent like circuit board. It saves many a headache to use a breadboard first.

mattman822 (author)2013-09-10

cool but the resistors get really hot

zaneg3 (author)2016-04-05

It's not a good idea to use resistors at their actual power rating, you need to get stronger resistors, or reduce the voltage while maintaining resistance.

dsand (author)2016-03-24

thank you i have been reading alot of confusing books but your intructions are clear and accurate. thank you

haltenfelder (author)2016-01-30

In the name of all breadboard-noobs:
Thank you!
(did u know that the original breadboard was a board of wood with nails, that were connected with wires)

Hi, this was my first project and these instructions really helped. I understood a bit previously from school, but I'm very proud.

Thank you!!!

dmalish (author)2015-04-01

Thank you! I have been looking for stuff like this, and until now have yet to fined one that actually made since to me.

russ_hensel (author)2015-03-14

Just a note to let you know I have added this ( a year ago ) to the instructable:

Comprehensive Guide to Electronic Breadboards: A Meta Instructable

Take a look at a bunch of project involving breadboards.

Cew27 (author)2015-03-14

Thanks for notifying me.

I appreciate the credit given!

SamsonP (author)2015-02-09

Absolute beginner here, I was doing it all wrong. This helped. Thank you. :)

filippo69 (author)2014-12-17

5eBoard is the best solution for solderless boards especially for beginners. Modules can be placed anywhere on the board for easy clean projects.

http://www.5eboard.com

c.ionutmihai (author)2014-10-25

Thank you very much for your work. It's greatly appreciated.

Cew27 (author)2013-04-15

i appreciate everyone's tips and suggestions, unfortunately i havent updated any instructables in the last 3-4 years due to my commitments to university and other projects. However i am studying electronic and electrical engineering and have a few projects coming up so no doubt i'll be able to post some new stuff and overhaul the old stuff.
once again i appreciate all the comments!

psingh46 (author)2013-04-02

Overall this was a great set of instructions but i have a few suggestions.

1) for the last few pictures, take them with a dead bulb just so we can see the how the connections are made more easily.
2) maybe in addition to the photos of the breadboard, a few basic handdrawn/computer-made diagrams(with the component rows spread out) that would make it easier to see where things are plugged in relatively to each other.
Thanks though. it was quite informative

jcastrillon restrepo (author)2013-03-23

I didnt got quite well the paralel and series connection form
So, - - is paralel? and - - is series? THANKS
- - - -

agm88 (author)2012-11-29

i realy needed this thank u

Hansrudi (author)2012-07-07

This bis a great introduction, thanks a lot for your help.

YellowZealot (author)2011-07-23

I don't know if you've taken basic physics of electrics, but resistors in parallel average out, so three 100 ohm resistors along 3 parallels would still be 100 ohms resistance, the same for a 100 ohm and 200 ohm along two parallels, it would be 150 ohms resistance.

ixisuprflyixi (author)2011-12-08

Not sure why no one has corrected you since July but you seem to be mistaken, or you are trolling. However, 3 100 resistors in parallel would be 33.33 Ohms as per schumi23's formula above. and 100 ohm in parallel with 200 ohm would be 66.67 ohms. See the total resistance for a parallel branch MUST be smaller than the smallest resistance. So it would never be any larger than the smallest resistance. Thanks.

pennsteve (author)2009-12-30

Question.  Say you need 8 Ohms, and you only have resistors of like 50 ohms and higher and no two are alike, is there an easy formula to quickly figure out which combination you can use to get at or near 8 ohms?

I realize you can just start doing calculations on different resistor values, but that can take some time.

Thanks

schumi23 (author)2011-11-26

I'm pretty sure the formula for resistors wired in Parallel is
1/rt=1/r1+1/r2+1/r3...
Were rt is the total resistance, and r1=r2=r3...
I'm not sure, but that's what i remember. Google Resistors and parallel and you will find the answer.

pfred2 (author)2009-12-07

bowmaster (author)2010-11-27

Dang, I want one. Where'd you get it?

pfred2 (author)2010-11-28

I bought it a piece at a time and double back taped it all to a big piece of Plexiglas. Then I stole the line from Crocodile Dundee, you know the that's not a knife scene?

Really it is a bit excessive today, but it was handy years ago with SSI TTL. All up and running that board drew about 5 amps too! But this was attached to it as well:

http://img708.imageshack.us/img708/1643/p7100090.jpg

bowmaster (author)2010-11-28

What is that? It looks like a clock.

pfred2 (author)2010-11-28

It is a 6 digit binary and hexadecimal latch, driver and 7 segment display. It connected to the cables that are sticking out of the breadboard. It was for displaying memory and address values of the computer circuit.

chanfle (author)2009-12-30

"....[the] short one connects to the -ve end of the power source and obviously the longer leg to the +ve end. this is because an led allows electrons to flow easily from the cathode(-ve) to the anode(+ve) but not from the anode to the cathode."

Is that correct?  We're talking about positive-convention current (+ to -), aren't we?

Cew27 (author)2010-01-02

im talking in  terms of electron current  not  conventional

jwarning (author)2009-12-12

Thanks a bunch! Just what I was looking for!

mitchell931993 (author)2009-10-17

wow thanks man. we always pull these out accidentally in physics while looking for aligator clips and resitors, no one knew what they were for :) thanks bro

SquirrelFlapps (author)2009-07-23

Awesome Tut... i greatly benefitted from both this instructable and your previous one. Im 19 and currently attempting to take up electronics as a hobby and a way to relax and simultainously stimulate my mind, however its like good electronic tutorials belong to secret clubs or something. idk lol this was a good one tho.

thepelton (author)2009-07-16

I remember my Mother saying: "That's a breadboard? Wouldn't the crumbs get stuck in all those little holes?"

designguy1982 (author)2009-07-16

@ Zem Both a breadboard and a circuit board, ( I will assume you mean printed circuit board, PCB) serve the same electronics function. The difference is that a breadboard is used for prototyping PCBs due to their speed, flexibility and reusability. Once you get your circuit up and working as expected, you can then etch your own PCB if you want. While not necessary, starting with a breadboard can save one, a lot of headache later. I hope that answers your question. Take Care

Joachim Bates (author)2009-07-10

Could you give me a link to a website on basic electronics so i could learn more and have you got more instructables on basic electronics as I am new to electronics and really want to learn more. Thanks

Jayefuu (author)2009-07-15

evilclutch (author)2009-07-14

a very nice guide, thanks alot

miiwii3 (author)2009-07-10

on my bread board it has the power going strait own the entire row.

miiwii3 (author)2009-07-10

i deleted my own comment i accidentally posted it

Blue_iiz (author)2009-07-09

That would be done using the formula P = I * V, but would you please explain how to calculate the current and voltage going through each resistor?

RonArcherAlias (author)2009-07-09

if it is a simple series circuit the current will be the same anywhere within the circuit. to calculate the current in this series circuit add up all the values of the resistors and use ohm's law (V=IR) to calculate the current (I=V / R). then multiply the newly found current by the value of the resistor in question to calculate the voltage through that resistor.

Joachim Bates (author)2009-07-09

Very helpful. I understand a lot better now.

Zem (author)2009-06-11

I have a slightly stupid question... If your LED is say, 3.3v and you only run it on 3v, do you need a Resistor?

Cew27 (author)2009-06-11

yes to step down the current, however you can run an led with no resistor but it will reduce its lifespan and it may get hot

Zem (author)2009-06-12

Okay, thanks.