To be able to read schematics you must know the schematic symbols. Here is an overview of the most used symbols in circuit diagrams.
Battery
The symbol for a battery is shown below.
A large and a small line is suppose to represent one battery cell so that the image below would suggest a two-cell battery of 3 V. But usually people just draw the battery symbol with one or two cells no matter what voltage it is.
The battery symbol
Capacitor
Capacitors are either polarized or not. The symbols that are used for the two are shown below. Both in European and US style.
A polarized capacitor is marked with a “+” sign. It is important to distinguish between these two because the polarized capacitor needs to be placed correctly according to the “+” sign.
 Standard capacitor (EU style) |
 Polarized capacitor (EU style) |
 Standard capacitor (US style) |
 Polarized capacitor (US style) |
Resistor
The schematic symbol of the resistor are drawn in two different ways. The american style resistor is drawn as a zigzag resistor while the european style resistor is drawn as a rectangular resistor.
Even though I’m from Europe, I like to draw the zigzag version. I think it is easier to draw and looks better.
 American style resistor |
 European style resistor |
Variable resistor (Potentiometer)
The variable resistor or potentiometer is drawn in several different ways. The symbol is often drawn as a resistor with an arrow across it or pointing down on it as the one below.
Variable resistor
Diode
The diode family has several different symbols because there are several different types of diodes. Below is a standard diode, a zener diode and a Light Emitting Diode (LED).
 Standard diode |
 Zener diode |
inductor
Light emitting diode (LED)
Schematic Symbols of a Transistor
The most common transistor types are the Bipolar Junction Transistor (BJT) and the Field Effect Transistor (FET). The schematic symbols for these two types are shown below.
 Bipolar Junction Transistor (NPN) |
 Field Effect Transistor |
Inductor
The inductor symbol looks like a coiled wire as this is what an inductor essentially is.
Inductor
Integrated Circuit
Integrated circuits (IC) are usually shown as rectangular boxes with pin names. Below, an example of the 555 timer IC is shown.
The “555 timer” integrated circuit
Logic Gates
Here are the schematic representation of the 6 logic gates.
Logic gates
Operational Amplifier
The operational amplifier or “Opamp” is represented as a triangle with two inputs and one output. In some cases, the power supply pins are also added. Below, a version without power supply pins are shown.
Operational amplifier
Switch
A switch can be represented in numerous ways in electronic schematics. Below is one example.
A simple switch
Transformer (Trafo)
The symbol of the transformer looks like two inductors with something in between them.
The transformer symbol
Fredo says
June 20, 2014 at 5:35 pmIt would be nice to also include the european version of the logic gates.
Also I prefer the european version of the resistor since a sloppy drawn zigzag might also be a coil.
admin says
December 1, 2016 at 1:32 amGood point. I’ve always found the european version of the resistor a bit boring. But I see your point about a sloppy drawn zigzag-resistor.
Oyvind
Hank says
September 22, 2017 at 2:25 amYes that is a good point. I’m always critical of fine points like that, that a lot of people don’t think of.
But I’m an OLD guy now (been around for a long time), and I’ve used the zigzag resister symbol all my life. My response then is if it’s sloppy and can look like a coil (which is true), just don’t be sloppy!
Another thing: The European style symbol can look like an object on a computer flowchart, many of which I have also made. So I’m not crazy about it’s boxy look because I’m used to that being on flowcharts.
kingsleydara says
August 4, 2014 at 10:32 amim a beginner in electronics, pls i nid hlp in reading intergrated circuits, its uses ,nd major function of a electrolyte capacitor
admin says
August 4, 2014 at 8:12 pmCheck out this page: http://www.build-electronic-circuits.com/basic-electronic-components/
Oyvind
opolot david says
March 23, 2016 at 7:12 amthanks nice course for me Ilove thise help me brother.
Sam says
April 25, 2016 at 7:15 pmyou realy should put a PCB on this as i need it and others might to
admin says
April 26, 2016 at 8:17 amNot sure what you mean… A PCB does not have a symbol.
Oyvnd
David Hetherington says
August 17, 2016 at 1:31 ama PCB is the board, but some of the capacitors have difference marking for the cap. positive.
chloe says
September 13, 2016 at 3:02 pmthis is useless
Sensis says
October 6, 2016 at 6:40 pmWhat’s the usefulness of this comment?
It’s basic electronics for people that don’t know it.
If you’re so good, create your own website, and please, do it for the pros…
And please do forget co the link.
Bless! S.
Sensis says
October 6, 2016 at 6:43 pm*And please do forget to share the link.
ifeanyi job says
January 11, 2017 at 10:45 pmwonderful. Thanks alot
Malachy says
January 22, 2017 at 4:24 pmPlease i want to learn more about electronics component and fuctions
admin says
January 24, 2017 at 6:08 amMaybe this could help: http://www.build-electronic-circuits.com/basic-electronic-components
Best,
Oyvind
chris mularn says
February 19, 2017 at 9:08 pmthanks guys this is great! i have just learnt so many things and understound basic electronics.thanks
admin says
April 17, 2017 at 4:59 pmGreat!
Damilare says
April 14, 2017 at 3:29 pmGod bless the developer of this site and the above writer-up . I have really gained a lot today. But , I will appreciate if u can write up how to configure the pins in an integrated circuit as well as what each term stands for? God bless you….
admin says
April 17, 2017 at 4:59 pmHi,
Maybe this could help:
http://www.build-electronic-circuits.com/integrated-circuit/
Best,
Oyvind
Liran says
July 14, 2017 at 1:28 amThank you very much Oyvind :-)
Can you please explain how to reverse engineer a schematic from a circuit board?
Nadeem says
July 14, 2017 at 12:37 pmVery good tutorial, we learned lot , thanks
Nadeem says
July 14, 2017 at 12:39 pmThanks dear, tutorial is very good and simple to learn
Amir says
August 21, 2017 at 12:03 amPlease help. I’m new in this world…
On schematic, resistor with % mark instead of resistance?
What iz mean?
Thanks
admin says
August 21, 2017 at 9:50 amThat’s the precision of the resistor. 5% means the actual value is within +/- 5% of the marked value.
g says
May 8, 2019 at 5:26 pmdefault
Margaret says
September 5, 2017 at 2:21 amThank you for your tutorials! Is it possible to have a printable link for some of your pages, like this one? Thanks!
admin says
September 12, 2017 at 10:11 amHi,
I don’t have any way of offering that at the moment, but you could try just the print option of your browser.
Best,
Oyvind
Friday Matthew says
November 29, 2017 at 9:32 pmPlease list the parts and their functions
admin says
December 1, 2017 at 5:16 pmhttps://www.build-electronic-circuits.com/basic-electronic-components/