Correct labelling beside DC socket?

I like this one, which is very clear, if you have the room for it. They don't show the symbol for DC-out on this adapter.

You can choose whatever you like, there is no common convention or specification AFAIK. Mr. Woodgate will correct me if I'm wrong. Maybe a semi-circle for the outer conductor is intuitive. The same socket can also be used for low voltage AC supply BTW, in which case the polarity won't matter.

Things that use those plugs usually have a polarity symbol next to the socket. I'd copy one of those.

Leon

The circle and dot show the polarity. That is intuitively simple.

A single bold straight line shows it expects to be fed with a regulated supply. A bold line paralleled with a dotted line shows it expects to be fed with an unregulated supply with a nominal voltage as written..

I have seen the dotted line above and below the solid line.

Gibbo

supply.

an

Thanks Gibbo. I'm using unregulated DC so from what you and others have said either way around is fine. I've got the circle and dot arrangement in place to indicate polarity too.

Steve

The OP appears to be asking for the symbol for 'DC', not for the connector. The ISO/IEC symbol has the dotted line below the sold line.

The symbol for the connector is indeed a '-C' for the outer contact, with an 'o-' embedded in it for the inner contact. It's a symbol that's difficult to simulate compactly in ASCII art.

Many thanks John - yes it was the standard for the solid line and dotted line that I was after. I've got the circle/dot system already in place (copied from other kit). I will use the ISO/IEC system you've stated - dotted line below solid line.

Steve

--- (DC) / ------- | - - - - | O------------ | / --- | o------------ | === GND created by Andy´s ASCII-Circuit v1.24.140803 Beta

You're right -- not compact at all. (;-)

Chris

I read in sci.electronics.design that CFoley1064 wrote (in ) about 'Correct labelling beside DC socket?', on Sat, 18 Dec 2004:

You can do a bit better than that:

_ / ----| o---- _/

.... but it's hardly elegant.

Those markings relate to the supply not the connector.

I see John Woodgate's reply pretty much replicates what I was about to say.

If you're designing something to take a wall wart - please put a diode bridge after the socket so that it's not polarity sensitive. It's such a pain otherwise. Better still, add a reservoir cap so it'll run off AC or DC !

Graham

They do ?

Curious that some wall warts are supplied with a polarity reverser then !

Intuitively that would seem to suggest polarity to me. I would expect the general public to uderstand though.

If the socket isn't polarity insensitive, I'd mark it clearly with a plus and minus symbol next to the connector.

Graham

I read in sci.electronics.design that Spehro Pefhany wrote (in ) about 'Correct labelling beside DC socket?', on Sat, 18 Dec 2004:

It's clear but there is now an attempt to make standard that the centre contact is positive. Note 'make standard' not 'make a standard' - it's far too late for that.