POWER SYMBOL

A 'power symbol' is a symbol indicating that a control activates or deactivates a particular device. It incorporates line and circle figures, with the arrangement informed by the function of the control. The universal power symbols are described in the IEC 60417 standard, ''Graphical symbols for use on equipment'', appearing in the 1973 edition of the document (as IEC 417) and informally used earlier.
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Contents

Definitions

Standby symbol ambiguity

In popular culture

References

Definitions

	IEC 5007, the power on (line) symbol, appearing on a button or one end of a toggle switch indicates that the control places the equipment into a fully powered state.
	IEC 5008, the power off (circle) symbol on a button or toggle, indicates that using the control will disconnect power to the device.
	IEC 5010, the power on-off symbol (line within a circle), is used on buttons that switch a device between on and fully off states.
	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. This may appear on a toggle switch opposite a power on symbol, alone on a pushbutton that places the device into a standby state, or alone on a button that switches between on and standby.Alternatively, under IEEE 1621, this symbol simply means "power".[2]
	A crescent moon, indicating sleep, is added by IEEE 1621 as a replacement for the standby symbol.

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 symbology was published as IEEE standard 1621 on 2004-12-08.

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In popular culture

The standby symbol, frequently seen on personal computers, is a popular icon among technology enthusiasts. It features prominently in the Applegeeks webcomic, and can even be found on T-shirts [1]. It has also been used in corporate logos, such as for Gateway, Inc. (circa 2002) and Exelon, and even as a personal tattoo.

References

1. The Power Control User Interface Standard (consultant report) Lawrence Berkeley National Laboratory
2. Power Control Made Easy
3. Draft Standard for User Interface Elements in Power Control of Electronic Devices Employed in Office/Consumer Environments (consultant report) Lawrence Berkeley National Laboratory
4. Save Energy at Your PC; Energy Scientists Propose Color-Coding Standard for PC Sleep Mode
5. Power Management Controls - User Interface Standard - IEEE 1621


★ IEC/ISO Database on Graphical Symbols for Use on Equipment

★ ISO/IEC/JTC1 Graphical Symbols for Office Equipment, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory