No, the one-inside-a-circle symbol does not indicate a toggle between off and on, as this article "surmises".
Instead, it indicates stands by. This is off, but not fully off as a circle would suggest. It's nearly on. The symbol is great for that.
On a push button it means activate stand by or come back out of it (i.e., turn back on fully). Still fair enough.
Unfortunately, this knowledge has watered down over time. I've seen that symbol used more than once for a button that only turns on a device (never back to stand by). That's pretty much the opposite of its original meaning.
> No, the one-inside-a-circle symbol does not indicate a toggle between off and on, as this article "surmises".
According to https://en.wikipedia.org/wiki/Power_symbol#Standards, "one inside a circle", IEC 60417-5010, is a fully-on/fully-off toggle. The "one breaking a circle" symbol, IEC 60417-5009, is a fully-on/standby toggle.
Agreed but the "one breaking a circle" stand by symbol, IEC 60417-5009, is what the article seemed to be referring to by "one inside a circle", given the pictures shown. I just copied their imprecise description.
I'm glad you clarified. The symbol has always represented an open 'O' vs closed '|' circuit to me (never bothering to look at the standards). The fully inside vs breaking is still fitting in that context.
Interesting! Per your Wikipedia link… there was an early ‘00s proposal for a dedicated sleep symbol: line through a crescent moon. Same proposal would have defined line-through-circle as the generic power symbol. Though, this was superseded with standard for using only a crescent moon to indicate standby.
“Standby symbol ambiguity
Because the exact meaning of the standby symbol on a given device may be unclear until the control is tried, it has been proposed that a separate sleep symbol, a crescent moon, instead be used to indicate a low power state. Proponents include the California Energy Commission and the Institute of Electrical and Electronics Engineers. Under this proposal, the older standby symbol would be redefined as a generic "power" indication, in cases where the difference between it and the other power symbols would not present a safety concern. This alternative symbolism was published as IEEE standard 1621 on December 8, 2004.”
Interesting. I remember when that symbol was first getting used, but I don't remember anyone ever explaining that until you just did now. To me, it always meant "on/off" (counting "standby" as "off"). I thought it was just an artistic way of taking the "1" and "0" that was often used on power toggle switches and combining them into a single symbol for a single pushbutton (the "1" is inside the stylized "0").
Indeed, and even in 2008 when this article was written Wikipedia had this explanation
> IEC 5009, the standby symbol (line partially within a broken circle), indicates a sleep mode or low power state. The switch does not fully disconnect the device from its power supply.
I think it’s mostly true for modern usage. Powering off a laptop doesn’t fully disconnect power, because the power button is not a true switch but just signals to some power management hardware which is ALWAYS on as long as there is battery charge or plug power — it catches the signal from the “power” button and executes a true power switches to start the computer boot cycle.
The 1/0 thing confused me for a while because 0 looks like a circuit (on), and 1 doesn't (0ff). I was also taking electrical engineering classes at the time, and the 1/0 true/false thing was already halfway arbitrary because of active-low pins, and even in software land, "return 0" could mean either true or false depending on the context.
I agree that I/O has always been confusing and non-intuitive. O stands for "On"? For "Off"? I means eyes-shut? O means eyes open?
The new symbols aren't any better but the UX of "push this button to turn on or off" combined with obvious lights/etc when something is on has mostly made the semantic meaning of the symbols obsolete to 99% of consumers.
The difference between perfect circle, 'o', 'O' and '0' is contextual, since the shape of all four of them is approximately the same. On their own, the characters themselves are often ambiguous in print, and totally ambiguous in handwriting.
There is an exhibit right now at the Cooper Hewitt Design Museum in NYC about
the work of Henry Dreyfuss did with his Symbol Sourcebook (https://www.cooperhewitt.org/channel/give-me-a-sign/) which heavily influenced the design of most symbols we use today, including this one.
Then there's standard walls switch in Europe, which works whichever way the electrician happened to wire it. And then, existence of "stair switches"[0] means you can't ever rely on directionality being consistent.
Now, let's talk about water faucets and which side is hot, and which one is cold...
--
[0] - Don't know what the formal way for these are; I'm thinking of two switches hooked up in a XOR pattern to the same light - i.e. light turns on when the switches are in opposite positions, and off if they're in the same position.
(US here) -- I remember to install light switches so that the up position is "on" because of a faulty light switch I had decades ago -- the spring holding the position was broken so that, over time, gravity would eventually make it fall to the lower position.
Having the lower position be "off" seems like a good failsafe for that sort of thing. I don't know if that's why the convention, but it is the mechanism that I use to remember what the convention is.
I have actually seen the diamond "start" symbol [0] on ONE consumer-ish appliance! It was an office coffee machine at my old job, big green membrane IEC start button.
These symbols are ubiquitous on industrial kit (and in your car, surprisingly enough), it's kind of a shame they are barely used at all else where. There's a pretty wide vocabulary of symbols.
Photocopiers? Yeah, I saw that symbol on some of them. But then even some of the image results show that manufacturers of photocopiers and printers, particularly targeting general consumer market, let their designers get creative with the shapes, colors and labels on the buttons.
"insert the side that already has writing face up, and the side that is blank face down"
OR
"these lines represent what will happen after you print but they're just being represented here for your imagination purposes even though they aren't there yet so you should really put the blank side up even though we are drawing lines on the up side"
My approach for over a decade now has been, before any "manual duplex" printing, to start by marking the top page in the tray with a little arrow pointing upwards, drawn with pencil or pen, in the bottom right corner of the page. I'd then print one page (and/or print a test page), and check the position of the arrow, to learn how the particular printer behaves.
To date, I've probably seen every possible orientation of the arrow on the output. Some printers do insane things to paper.
Likewise the indication (if any) on a sheet-fed scanner tray that tells you whether to put the paper in face up or face down.
I've taken to just writing instructions to myself on that type of thing with a sharpie, using actual text, and/or an actual diagram. It works well with the usual beige plastic. If it's black, I usually put it on a small piece of paper and tape it somewhere it won't interfere with the operation.
Not everything has to be an icon. IMO, bad icons are far worse than no icons.
Yes. Cars used to have words like "OIL" or "TEMP" or "BRAKE" or "SEAT BELT" in the dashboad warning lights. That switched to icons, probably as a cost-savings so they could use the same parts worldwide. But at a cost in clarity.
Now that most new car dashboards have programmable LCD displays or at least a message area, better/more descriptive fault descriptions have returned.
>"insert the side that already has writing face up, and the side that is blank face down"
More odd that it would be on a printer, but for a scanner, it is telling you that it will scan the side that is face up. For a printer, I'd be willing to be that icon is telling you that it is going to print on the face-up side.
That's the part that isn't clear. How do I know that the lines don't indicate "what is already printed" and the blank side indicates "the blank canvas that it wants as input"?
No discussion about use of 0/1 for power switches is complete without mention of the original IBM 5150 (original PC) power switch, which is the first place I ever remember seeing the "binary" 0/1 used to mean "power on / power off" on electronics.
Instead, it indicates stands by. This is off, but not fully off as a circle would suggest. It's nearly on. The symbol is great for that.
On a push button it means activate stand by or come back out of it (i.e., turn back on fully). Still fair enough.
Unfortunately, this knowledge has watered down over time. I've seen that symbol used more than once for a button that only turns on a device (never back to stand by). That's pretty much the opposite of its original meaning.