this instructable will show you exactly how to read all those confusing circuit diagrams and then how to assemble the circuits on a breadboard!

for all the electronics hobbyist wannabes this is a MUST-READ instructable.

knowing how to read circuits is a very useful skill that will help you out all the time. especially if you start messing around with building little electronics projects.

In addition to reading this instructable it may be a good idea for you to read my other instructable "electronics components and what they do" to get a good understanding of what you are doing when building a project. (woops not done with this yet, i got caught up with other stuff, check back in a week or so)
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Step 1: So What Are All Those Symbols???

Picture of So What Are All Those Symbols???
finished 2.jpg
here is a little guide that shows you the basic symbols for all sorts of components. its handy to keep a little guide like this around in case you forgot some. Plus, while you're beginning you might have to refer to it pretty frequently. I have boxed the most common symbols in red, these are the ones you should get to know by heart. the others you can always refer back to the guide for.

dont be overwhelmed its simpler than you think, just stay with me

Step 2: Okay, but how is each part connected?

Picture of okay, but how is each part connected?
physically parts are connected by wires, in the diagrams you will see black lines going from one part to the next. this means that you connect them with a wire

when the black lines cross in a diagram there are ways of telling whether or not the wires should be connected to each other as shown below.

Step 3: HOLD UP: What about Polarity?

Picture of HOLD UP: What about Polarity?
real polarity.jpg
some components to a circuit board are polarized, meaning one side is positive and the other is negative. this means you have to attach it in a certain way. for most symbols polarity is included in the symbol. in the the photos below you will find a guide to distinguishing polarity for various symbols. to find out the polarity of the physical part a general rule of thumb is to look for which metal lead wire on the part is longer. this is the + side.
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spirit x1 year ago

whats the symbol for a transformer

Here it is





Symbol for transformer is:

NakshN2 months ago

Good work!

Help me a lot.


R&D Engineer


hi! i am a grade school student and one of our project is to pickup invention in instructable site. i have chosen your laser trip wire as my project but i am having a difficulty in finding the circuit board. The store just gave me project board to use as circuit board but i don't have any idea on how to use it. can you help me,please?

nicklovesgod4 months ago

Great instructable ! I read because I am creating a computer and I'll need help!

Acn8s.5 months ago

Small questions being answered TY.

PhiM16 months ago

very easy to follow so far

mabearden6 months ago

Great!!! Thank You

I'm it trying to be a cynic, but I think that the diode was improperly labeled in the schematic. By all means, correct me if I'm wrong, but aren't LED's supposed to have two little lightning bolts along side of them?

i thought the same thing, lightning bolts are unfamiliar to me, but i've seen 2 arrows pointing away from the triangle showing light is being emitted from it

JimC27 months ago

Will someone please explain the correct way to wire a switch to this from the #14 12vdc switch input?

In step#9 it says " customer supplied switch" , just not the correct way to wire the switch, I contacted the mfg, but did not hear back from them


Thanks in advance

HarishB11 year ago

very helpful sir.i am an electronics and communication student.thank u.

STEMsheets1 year ago

You may find these customizable flash cards useful for learning circuit symbols: Circuit Symbol Flashcard Maker

VERY helpful...One question though...If when reading a diagram if the wires are connected on the diagram BEFORE a switch post but go right into a switch post after the connection when you are wiring do you solder mid wire or at the switch post thing?

This is helpful, especially for those who want to learn more about circuitry, and for us engineers to further enhance our ability and familiarization on symbols and types, Great!

i like it

jkleyn1 year ago

Thanks! Pure simple and Clear.

spirit x1 year ago

can some one tell me how to use a 8 pin mini transformer

spirit x1 year ago

whats the symbol fora transformer.

K Nyarko1 year ago

helpful intro

shallowman1 year ago
Great intro, however I would really like to see you explain a more advanced circuit schematic.
okhajutt1 year ago
GeoEg2 years ago
Excellent Intro!
ndav2 years ago
excellent introduction to circuits, thank you
very nice Thanks to giving me ausefull information
ash3032 years ago
good stuff. Thanks and keep it up!
sbroom92 years ago
great site easy to understand glad i found it
spikec2 years ago
Nicely done. Your series of 'ables is awesome, thanks!
bvillamor2 years ago
thank you for the information
bvillamor2 years ago
thank you for your information
jamanda2 years ago
THIS WAS AMAZING!! Thank you so much ! This helped my land an electronic assembly job !! KEEP IT UP!
I wish radioshack sold those kind of breadboards....
apaterson14 years ago
i'm struggling with one particular symbol it looks like lots of connected ohm signs or some interconnected circles can you tell me what this is *note* it is not an inductor or a coil
4269srd4 years ago
i like it! but you should go into a little bigger schamatics. im going to see what other things u have. thanks!
 the symbol for Diode(D),Photo and Gate,AND look exactly the same. what is up with that?
Yes. that's a mistake. The symbol of AND gate looks the same as NAND gate when you remove the dot near the output.

Symbol for NOR gate should have a dot similar to the NAND gate near the output.
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