How to Read Schematics

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Do it the old fashioned way. Buy a broken audio amp at the junk shop. Get a Sam's Schematic (Do they still make these?) and fix the thing. When you're done, you can read a schematic.

this is the best site I can find on exactly how to determine what is stated on your electrical drawings. http://www.learn-c.com/schemat.htm I just used google and put in the box, "How to read Electrical" and several choices popped up all of them have parts that might help you in your position. Here is a blog you might need to use "http://en.allexperts.com/q/Electrical-Engineering-1356/read-electrical-schematic-blueprints-1.htm" And this site will teach you how to draft "http://www.tpub.com/content/draftsman/14040/ " This site will teach you how to read construction bid drawings and working drawings "http://www.ehow.com/how_5020388_read-electrical-blueprints.html" Those should fill in the blanks your looking for.

See Engineering Symbols Prints and Drawings Volume 1 & Volume 2.

Links, of which sent by other friends are useful.

Useful only for trying to read and understand the schematics.

No need to say here, less information on electric is dangerous, more than not knowing anything. You have only one chance if you attempt actively to fix anything.

Kindest Regards.

Hi and welcome ajit,

Search for "electrical schematic symbols", and on the search page click images.

This is what you will get or you could copy this to an accessible file on your desktop perhaps?

electrical schematic symbols images

You could also download what you want and print to an A6 or A7 book size and print and fold it yourself. At this size a normal sized desk stapler will reach the centre to staple your book.

An alternative, is to use fishing line or just plain cotton sewn in two loops, where the staples would have been on the crease. If you want to make this last a bit longer in 'the field' you can put a card cover on the tiny book, and or, you can print then cut out each page and seal them in plastic and put them on a keyring.

You could even go down to A8 size, ~ Credit Card size.

It might be easier to print on card, cut out, layer in plastic, leave the plastic a little too long or wide to allow you to punch a hole to thread it on a keyring?

Any print shop will seal these tiny pages in solid plastic for you if you take the finished printed sheets in.

I did this with conversion charts and distance measures I had to use all the time but could not recall. I still have then 24 years later!

Good luck.

Hi,

This OP (Original Poster) has had some pretty good site recommended. A couple of the post' have hooked onto Ladders, where the OP just asks about schematic drawings in general I would think.

Think can be for many reasons like finding a fault in his vehicle?

I think the advice to work with colleagues is goos if this is with regard to a work situation which is not at all clear. To me this OP is asking just to find out, and it may be the first time he has set eyes on a schematic?

The broad scope of the answers from professional Engineers to Guests should help and I ask you, the OP to let us know if and how the replies helped you please?

Good luck

I'm guessing the poster is trying to read ladder logic schematics and not circuit diagrams. Here is the link to the wikipedia article on ladder logic: http://en.wikipedia.org/wiki/Ladder_logic Usually there is also an engineering conventions page, usually near the front of the schematic, which should shed a little light on the schematics.

Shawn

In that case, I'd suggest getting a busted refrigerator and diagnosing it. The circuit is usually a ladder. I'm not sure how you wind up an engineer without knowing Boolean, but there's no substitute for hands-on.

I'm guessing the poster is trying to read ladder logic schematics and not circuit diagrams.

Just don't know, could also be PI&D . I think Abdel gave some good links for that

p911

The initial thing is to have some tutorials from a professional or study in a technical institute.

Learn Tecnical symbols and proceed furthe.

Every country and even every major company has its own drawing systems for Electrical /Electronic schematics.

The best I know is by Siemens which draws as usual that is starts from left with co-ordinates like a Street-Map used in Europe & Americas with 1 2 3 ...... the end on top as horizontal & A B C .......on the sides as the vertical co-ordinate.

in the bottom under each line reference to the relative component is given.

It was most helpful for the field engineers /Technologists.

Hello Haajee

I agree, you have to know what all of the symbols represent or you're lost before you get started.

This is another good pdf tutorial from Siemens regarding circuits and most symbols you'll encounter while deciphering their schematics (and others).

I started buying the packages of colored sticky flags (page flaggers) from the office supply store to flag pages of the Siemens style schematics. They really saved me allot of grief when digging deep into a problem or when documenting changes/additions. Sometimes you just run out of fingers.

Hope this helps the OP in his quest.

Thanks for new information.

Symbols used by Siemens are mostly used in Electrical drawings while in Electronics vastly differ to thse.

Anyhow it is most important to be conversant to the ones being used in the project you are working on.

Hi snygolfgs,

I partly agree with your post but, I learned from reading a book which matched the symbols on my Radio schematic to the meaning and what they were for in that circuit.

What was at first like a map of the London Underground in Russian, gradually became a map of the Underground in English.

What was a complete mystery was fully understandable. My interest started when I read how a Phase-Lock-Loop circuit and how it worked. This is far from new but it was new to me at the time. I wanted a Radio whose signal did not wander. I did some reading and found what I needed. "PLL". And after getting the radio it came with a schematic with symbols but no explanation. So I think I found the symbols in a Physics book. And was able to understand why each component was where it was and what it did.

To someone who has gone to School and learned this, fine, they will always be one step in front of me. But, the only way I could find out what the symbols did in the radio circuit was to start from scratch. Step by step, and I knew how that particular circuit worked. I can now know roughly how some circuits work but when I got my first radio with PLL was a pretty long time ago and I am not at all up to date with todays systems.

The circuits of today, whatever circuits they are, they are still assembled from the same 'building blocks'. Whether a route to learn is a symbol list then book of explanation, or, a book of explanation first with an enlarged system symbols list afterwards hardly matters.

I think the OP is in this position, and how they learn and what they learn, does not necessarily put anyone in danger. Its just that you have to start somewhere, you know?

The size of each component is in the colour code on that component, with different colours representing certain amounts that is directly related to how 'powerful' the circuit is and what item you are likely to find that in.

Check out these:

Electronic_color_code for Electron Components

List of active and passive components and colours search page.

I have listed these sites for anyone not aimed at you snyfolfgs, OK? Just for people starting out.

Take care and Good luck.

Hi snygolfgs,

Just a quick word................

Thank you for your kind words my friend.

I had my radio, the schematic, and a list in a book which had symbols illustrated. It took a while but it did sink in eventually!

The OP sounds pretty young so I do think he is likely to be endangering anyone. And they have others help as well as mine so it should get the message over. That is if the OP reads the thread? I have not seen another post from him?

Take care and I hope you have a good night!

You mean you are really an electrical ENGINEER? (EE)

Where did you study?...

Dear friend,since u are not in the electrical field,u may not find it easy to read and interprete electrical schematic drawings.Though u need electrical experience.

But as u are eager to know it to assist yr supervisory job,the best teacher u need now is to consult an electrical engineering colleaque who will teach u much faster and better than web sites.U may not necessarily need an engineer for this,but employ the service of an experienced electrician or electrical technician who will teach u faster than expected.

Whoever can give u what u want in less time,drop any pride,go for him and get what u want.We all need electrical/mechanical supports(borrowed courses) to get good results in our fields of study.

Patrick Whowha

Great sites from previuos posters

I have seen and experienced this, as an ME people look to you for what ever reasons, approachable, available.....

One thing is, do not try to blow smoke to the maintenance supervisor, be straight with him and tell him that this not your forte/fortay, but will get through this together.

You'll both learn from it, as well as gain respect because of the honesty. Any kind foot work such as symbol recognition/identifying you pick up on your end from these posts.

Good job of letting people know you need help from the beginnng, you should be ok.

p911

ETI has a course on Engineering Drawing Requirements, which includes electrical schematic and logic diagram lessons. If you're working with drawings which comply with nationally recognized standards IEEE, ASME, ANSI then this would be perfect. It would also help if you're the one responsible for creating drawings. Unfortunately many companies make drawings that do not conform to established standards. They make up their own symbols, cross non-connecting lines, and use codes only undertood by their company. This is the primary reason why getting an old speaker and the corresponding schematic and working through the schematic will not actually prepare you to work with electrical schematic drawings ... your only learning one company's take on defining electrical curcuit functions.

Use the link below to learn the most common and industry approved practices.

http://www.etilearn.com/

Hi and welcome GDT Mentor,

I do not think I have spoken to you before which is why I say welcome!

In future I will shorten your name to GDTM. When working with a whole lot of respondents it is a real pain for me personally to try and figure out the user-name, OK?

Good luck.

I am also mechanical engenieer it is easy to redy electrical diagram normaly come in ladder system or acording the ISO standart. (I work in Europe) but you can find book with the electrical standar made by the diferents coutrys engineers associations .

You find also in the net the principal symbols , coils, contacs, motors etc.

Hi Guest,

some helpful stuff there. But please try and type a fraction s-l-o-w-e-r, to allow you to put the final letter on all the words.

Good luck.

An engineer that doesn't know how to read a schematic scares me!

Hi Guest,

The OP said he was a Mechanical Engineer.

Just in passing, ............. A plumber does not need to know the skills to manufacture a toilet bowl........... A pastry Chef does not need to know how to make flour........... Etc

Good luck

Bear - Please stop making stupid comments everytime someone posts a message

Don't be too scared. The spectrum that a ME needs or could to know can be quite broad.

I do not know of any ME that has the knowledge of the whole spectrum. He/She did what was correct and asked.

p911

I think there's a little more to this than just recognizing the sysmbols. One must also understand what the component does and how it does it. Knowing that the little box with 8 legs is an IC may impress a layman, but it doesn't really tell you much about the circuit. You need to understand what a FET is and how that works as opposed to a transistor (is that PNP or NPN?). You have to understand differences between steering diodes and free-wheeling diodes. What are all those capacitors doing and why are there so many resistors?

Bottom line - you need to understand the characteristics of the components, not just their names.

<< I think there's a little more to this than just recognizing the sysmbols. >>

Of course.

But it the initial thing to be conversant with symbols, in every type of drawings;

eg in Electronics symbol for a colenoid-valve is different tohydraulic or pneumatic symbols.

dear,

i think you were not study tha electrical drawing and its symbol or notation in your class room.there is no seperate web site for drawing,it is better you arrange one electrical engg. book and study about the notation and go through the drawing

thanks

rcmanadal