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Topic: How to make a schematic you can post. (Read 69 times) previous topic - next topic

johnerrington

Sep 19, 2020, 08:07 am Last Edit: Sep 19, 2020, 05:58 pm by johnerrington
When you submit a question on the forum you will usually need to add a schematic (circuit diagram).


To begin you must know at least SOME of the standards and symbols you will need.  
A great start is to watch this video.

After watching you could visit this site that has loads of information especially suitable for beginners;   and in particular a really nice list of the most commonly used symbols

You can also learn a LOT by learning to read schematics others have made.

Lets get started making a schematic you can post.
Fritzing or a photo of your layout aren't really satisfactory, especially if it has more than a few components.



Many advocate starting by drawing on paper and submitting an image. Here is a typical example. Its readable.  




However there are disadvantages to this approach; if you don't KNOW the right symbol you have no clue what to use to represent the component.

There are also some apps that are very easy to use for beginners and can make nice clear standards-compliant schematics.  The main purpose of this tutorial is to introduce you to just TWO that are particularly easy to use.

The first I have used for many years is Diagram Designer - get it here. Here is an example of me using it to make a diagram.



I start by placing my main component - such as the arduino. The standard symbol for complex circuits is a  simple box. Then I add more components, the wires to connect them, and finally the labels.

Remember where you can INPUTS go to the left, OUTPUTS to the right, positive voltages to top and negative to bottom.



Its an old package and the libraries are very limited but does produce good clear diagrams.


For more complex circuits a web-based package "circuit-diagram" has a big library of components - including the arduino and rasperry pi modules, and produces nice diagrams.  




Components show values and optionally designators - eg VR1. To add random text you need to search for the "label" component.

The component shows pin numbers in their physical place on the module. This is NOT standards compliant for your diagram, (as in not always flowing left to right input -> output) but can be helpful when assembling the final circuit.  Compare this diagram with the diagram (Fig4) above to see the difference.  Its the SAME circuit.



To place the input (potentiometer VR1) at the left I've needed to run a wire across others. Notice that wires CROSSING dont have a dot, wires JOINING do.


More good resources:

Circuit symbols

Units & Symbols for Electrical & Electronic Engineers - Ebook covering all important standards

and of course wikipedia
I'm trying to help. If I find your question interesting I'll give you karma. If you find my input useful please give me karma (I need it)

UKHeliBob

Your images are not being displayed.  How big are they and how did you insert them ?

A recent change to forum functionality will insert images in you post automatically if you attach them to a post
Please do not send me PMs asking for help.  Post in the forum then everyone will benefit from seeing the questions and answers.

johnerrington

Thanks. 
Quote
A recent change to forum functionality
had me confused. Hope its all there now.
I'm trying to help. If I find your question interesting I'll give you karma. If you find my input useful please give me karma (I need it)

ballscrewbob

#3
Sep 19, 2020, 04:24 pm Last Edit: Sep 19, 2020, 04:24 pm by ballscrewbob
Sorry about that John.

There was some basic announcements in website and forum topics and hopefully people catch on to the picture fixes and other minor improvements that are ongoing.

Bob.


It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google (who would have thunk it ! ) or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

larryd

No technical PMs.
If you are asked a question, please respond with an answer.
If you are asked for more information, please supply it.
If you need clarification, ask for help.

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