Difference between revisions of "Common symbols around you"

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Some of the more commonly seen safety standardizing bodies and their certifications include:
Some of the more commonly seen logos / certification bodies include:
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UL.png|[https://en.wikipedia.org/wiki/UL_(safety_organization) UL] (United States)
UL.png|[https://en.wikipedia.org/wiki/UL_(safety_organization) UL] (United States)

Revision as of 14:56, 9 November 2019

Uses, safety

Power supply

basic DC adapter specs

The top symbol is for DC barrel plugs, specifying whether the inside or outside is positie.

The middle line is input, where the squiggly tilde ~ indicates AC.

The third line (output)'s solid and dotted line indicates DC.

Transformer (general)

isolating, safety isolating; non-short-circuit proof, short-circuit proof

separating transformer, output >1kV, variable, constant voltage, perturbation attenuating

Double circle, like a vertical venn diagram, are transformers, with a handful of properties marked. There are more combinations of all the parts this image shows, and further ones (e.g. construction site).


Some of the more commonly seen logos / certification bodies include:

Bunch on european certifications

You'll note that some of them are country-specific. There are many more country-specific testing centers. You're probably used to the ones applying to your part of the world.

In most places these are not required for sale, but for both safety and insurance reasons they are a good idea for both you and retailers.

For things like power supplies it's not uncommon to see a bunch more certifications, e.g. when a large company that has locked down the design so that they can mass produce it for worldwide sale without a lot of new certification.

CE Mark and Chinese Export
There are also a bunch of fake symbols, like the "chinese export", the latter being a nickname of chinese producers stamping CE (european) mark.

Often with different, tighter spacing (though some real CE products sometimes do this too for spacing reasons).


A bunch of the above are settled in ISO 7000 / IEC 60417, which also have a lot of markings used around mechanisms, indicatons, and buttons, around cars, audio, production lines.

See https://www.iso.org/obp/ui#iso:pub:PUB400008:en

IP ratings for water and object safety

clothing / washing labels



Single use, keep dry, don't use if package damaged