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Electrolytic capacitor symbols on circuit diagrams – point to watch out for !
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Chris56000:
Hi!

Can I take the opportunity to advise Members to be careful of electrolytic capacitor symbol polarities on some of the less well–known maker's circuit diagrams please?

Amber, who manufacture a range of audio testing equipment, use the conventional symbol of a black plate and an open plate, but for reasons known only to themselves, they've used the black plate as positive !

Some E. European makers that use the horrible i.e.c. symbol have used the "open box" plate as negative as well !

Admittedly these makers do clarify the polarity with a plus sign, but what's the point of having a "standard" when maker's invent their own variations on a theme?

The circuit symbols on my drawings (see my most recent posts on page 2 of this thread:–

https://www.eevblog.com/forum/testgear/soviet-oscilloscopes/

. . . here on the Soviet C1-112A Oscilloscope for an example) are based on those specified by BS3939 (1975 edition) which have been standardized by UK Electronic Magazine publishers since the last world war, and are almost identical to the symbols used in "Elektor"  magazine.

(I have added the Russian system of coding resistor wattage ratings on my C1-112A drawings as it saves adding endless extra part wattage references) – if a clear table is provided on the diagram there's no problems with this!)

The other reason I've not adopted the ghastly single–line '60617 representation is that my drawing software uses the older 1975 type symbols in it's libraries and I'm not going to spend hours redrawing them all just to please the Germans, etc., who dreamed up '60617 in the first place – they can keep them along with their horrible i.s.o./i.e.c. lettering !

Chris Williams
bob91343:
I still use the older symbology, a curved line for the negative and, just to be sure as well as redundant, a + symbol in case polarity is very important.
cortex_m0:
The standard is the IEC 60617 symbol - two parallel plates, with a + symbol on the positive plate for polarized capacitors.

If you're going to complain about deviating from standards, complain about deviating from an actual standard.  |O
David Hess:
The nice thing about standards is that there are so many to choose from.


--- Quote from: bob91343 on August 07, 2021, 11:15:05 pm ---I still use the older symbology, a curved line for the negative and, just to be sure as well as redundant, a + symbol in case polarity is very important.
--- End quote ---

That is what I do also, but I always include the + symbol.
rdl:
What I've read is that the curved line was to represent the outer can of polarized (electrolytic) capacitors, which is almost always the negative. Non-polarized capacitors used parallel lines (both sides straight). Having all types use parallel seems like a loss of obvious clarity.
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