Difference between revisions of "Common symbols around you"

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File:Double insulated.png|[[double insulated]], a.k.a. Class II
 
File:Double insulated.png|[[double insulated]], a.k.a. Class II
 
File:Reinfoced insulation.png|Reinfoced insulation
 
File:Reinfoced insulation.png|Reinfoced insulation
File:ESD.png|electrostatic discharge protection required
 
 
File:Electronic trash.png|Dispose as electronics
 
File:Electronic trash.png|Dispose as electronics
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File:RoHS.png|(and other marks mentioning RoHS)<br/>Compliant to [https://nl.wikipedia.org/wiki/RoHS RoHS]
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File:PSU types.png|Power supply type: switch-mode, linear, general/unspecified  
 
File:PSU types.png|Power supply type: switch-mode, linear, general/unspecified  
 +
 
File:Hot surface.png|Hot surface
 
File:Hot surface.png|Hot surface
 
File:Temperature protection.png|Temperature protection<br/>(surface maximum this temp in C under fault conditions)
 
File:Temperature protection.png|Temperature protection<br/>(surface maximum this temp in C under fault conditions)
File:furniture unknown MM.png|Can be used on furniture where flammatory properties are unknown
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File:furniture unknown MM.png|roughly means "safe to mount on somewhat-flammable materials" like wood, fabrics
 +
File:ESD.png|electrostatic discharge protection required
 
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Revision as of 19:27, 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.


LPS (Limited Power Source) have relatively low maximum voltage, current, and power. [2]

SELV (Safety Extra Low Voltage), where the power supply output stays safe under single fault conditions. [3]






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).



Certifications

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


Bunch on european certifications

There are also many testing centers, that may deal with additional health and/or safety and/or environmental concerns, though in most cases it's just country-specific.

You're probably used to the logos for the ones applying to your part of the world.


Certification marks, in the end, represent agreements between manufacturers and (ideally well known) testing centers. (and note there are logos that do not mean that at all)

In most places these are not strictly required for sale(verify), yet certification is quite common for a collection of reasons, like you caring about your safety, for company insurance (liabilitywise), varied indirect regulation (e.g. electrical code, fire regulation, medical safety) effectively only buying certified devices, or self-imposed regulation like caring that your house doesn't burn down and for related insurance.


For some devices (e.g. separate power supplies) you can see more-than-usual certification marks, for practical reasons: 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 (certifcation is slow, sort of expensive, and may need periodic recertification).



CE Mark and Chinese Export
There are also a bunch of fake symbols.

Best known among them is the "chinese export", a nickname of chinese producers stamping the european CE mark. Often with different, tighter spacing to have the argument it's not the same (note some real CE products sometimes do this too for spacing reasons).


Related

A bunch of markings used around mechanisms, indicators, and buttons, around cars, audio, production lines are settled in ISO 7000 / IEC 60417, see e.g. See https://www.iso.org/obp/ui#iso:pub:PUB400008:en


IP ratings for water and object safety


clothing / washing labels

Unsorted

https://hackaday.com/2018/02/02/what-are-those-hieroglyphics-on-your-laptop-charger/


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

Consumables