How to add a schematic if my mobile device can't run the schematics editor?

Question

I'm using a touch-screen device (a smartphone or a tablet) to access this site.

Hence, the built-in circuit lab won't work for me. What do I do to add a schematic to my question?

Answer 1

We take any kind of schematic, as long as it's clean.

Get a piece of paper, a ruler, a pen and get drawing and draw a clean schematic:

• Make sure you use the right schematic symbols
  • don't use any "fancy" symbols because you feel like it
  • don't draw resistors as little round components with colors, but use the normal US-American or IEC symbols (e.g. resistors are either "zick-zack lines" or "white boxes", nothing else).
• connections are vertical or horizontal. There's about two exceptions to that that also use 45° angles.
  • Exception 1: Wheatstone bridges
  • Exception 2: Bridge rectifiers
• connections are drawn with a ruler. No exceptions.
• Make sure you adhere to good schematic structure practices
  • Signal always flows from left to right.
  • Ground symbols always point down.
• It's mandatory components have names (e.g. R1, R2, C14, …), not just values (100 Ω, 2 kΩ, 100 nF), so that we can refer to them by name when discussing them.
• use a dot ⏺ to mark junctions between traces, and if it helps clarity, use an arch ∩ to mark a crossing that isn't a junction (i.e. where the two traces are not connected.

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Then, take a good photo.

Hints for taking good photos:

• use much light from around, so that there's no shadows or bright spot
  • using the flash is usually not a good idea, since that will overexpose some of the paper, but underexpose the rest
• Take a photo that isn't at an angle, but straight.
• Make sure the whole drawing is in focus – being sharp is better than being blurry but larger.
  • Check that the picture is sharp!
  • Your camera won't be able to focus on the paper if you're up too close. If you zoom in and the lines aren't crisp, try moving away from the paper.
• Rotate your image so that it's upright
  • (feels a bit stupid to say that, but reality is it's often missed) a 90° or 180° rotation is not acceptable
• Crop your picture to the relevant part.
• Most importantly, really check the image is OK before uploading it. Zoom in, and scroll around in it.

All that can be done with any modern smart phone or tablet.

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Couple of examples. Even the "this is good enough" example isn't perfect, on purpose. Neither is the way the schematic has been drawn. This all goes to show that with

OK, could be brighter and slightly more evenly lit, better white balance. This works, however.

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A shadow obscuring parts of the image. Sometimes hard to avoid when not having a lot of ambient light.

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Used flash: image overexposed in the center, underexposed elsewhere. Also, upside down, unsharp.

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Needs cropping. The relevant part only takes up a small fraction of the image area.

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Needs to be upright.

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Picture above is out of focus. Camera was too close to paper.

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Still out of focus, though not as badly, but still too close. Having more pixels of your schematic doesn't help if they're blurry!

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Pictures taken at an angle. A very common mistake, because one rarely looks at a piece of paper from straight above. However, one typically looks at a screen in a very straight way, so this isn't great.
Notice how due to the difference in distance, some parts are out of focus.

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Overcompressed; rarely happens these days, but when using image compression apps, make sure you avoid having such visible JPEG artifacts.

Answer 2

I once had a boss with lots of experience and a PhD but did not know how to use a computer, but he knew the power of a pencil.

Meaning: you don't need computer skills or even a schematic editor to be a great engineer.

This was filtered from @MarcusMüller 's last photo.

But you need some computer skills to make a readable photo.