I've never used this symbol before for a pcb screen layer but my software has a symbol that has a + sign slightly placed to the left and a large red band on the left also.
I'll assume that's the anode but of course my old school ways doesn't like a "band" for an anode marking. You guys know the symbol I'm talking about?
Easy to remember from the symbol...
K for cathode
A for anode
The band or + is always the cathode.
Well, this is the PCB silkscreen symbol, not a schematic and no A or K designation. I'll figure it out -- my software is Sprint layout. Wish everybody would just stick to an arrow and vertical line.
Message form the past -- if it ain't broke don't fix it. All of these idiots with nothing better to do make up their own. It's a fatiguing modern day phenomenon.
The bar on the silkscreen represents the bar on a diode symbol, in other words, the cathode. If you pretend it's spelt Kathode then the upper-case K looks like that end of the diode symbol which makes it easy to remember. Most physical diodes have the cathode marked with a band.
Likewise an A looks a bit like the other part of the diode. Fit a sideways A into a K and you have a way of remembering which is which.
The + on a silkscreen represents the cathode too, because this would be the positive end in a rectifier circuit.
I've never seen a + used to mark a diode. I think that is confusing and would not, as an engineer, associate it with the cathode automatically. For assembly it doesn't need to make sense, just be consistent, but also familiar. Consistently marking the cathode on diodes makes sense regardless of the nature of the mark.
Excellent mnemonic!
If you substitute the A with a spherical angle symbol, you can render the mnemonic in UTF-8 as K∢
Some spell it kathode, as a matter of course:
K --| <|-- A
The flat is the cat, the arrowed is the anode.
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