A power symbol is a symbol indicating that a control activates or deactivates a particular device. Such a control may be a rocker switch, a toggle switch, a push-button, a virtual switch on a display screen, or some other user interface. The internationally standardized symbols are intended to communicate their function in a language-independent manner.
The well-known on/off power symbol was the result of evolution in user interface design. Originally, most early power controls consisted of switches that were toggled between two states demarcated by the words On and Off. As technology became more ubiquitous, these English words were replaced with the symbols line "|" for "on" and circle "◯" for "off" (typically without serifs) to bypass language barriers. This standard is still used on toggle power switches, sometimes in the format "I/O".
The symbol for the standby button was created by superimposing the symbols "|" and "◯"; however, it is commonly interpreted as the numerals "0" and "1" (binary code); yet, the International Electrotechnical Commission (IEC) holds these symbols as a graphical representation of a line and a circle. [1]
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. [2] [3] [4] [5]
Universal power symbols are described in the International Electrotechnical Commission (IEC) 60417 standard, Graphical symbols for use on equipment, appearing in the 1973 edition of the document (as IEC 417) and informally used earlier. [2]
 | IEC 60417-5007, [6] the power-on symbol (line), appearing on a button or one end of a toggle switch indicates that the control places the equipment into a fully powered state. (1 or | means on.) |
 | IEC 60417-5008, [7] the power-off symbol (circle) on a button or toggle, indicates that using the control will disconnect power to the device. (0 or ◯ means off.) |
 | IEC 60417-5009, [8] 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". [9] |
 | IEC 60417-5010, [10] the power on-off symbol (line within a circle), is used on buttons that switch a device between on and fully off states. |
 | A crescent moon, indicating sleep mode, is added by IEEE 1621 as a replacement for the standby symbol. |
Because of widespread use of the power symbol, a campaign was launched by Terence Eden to add the set of characters to Unicode. [11] In February 2015, the proposal was accepted by Unicode and the characters were included in Unicode 9.0. [12] The characters are in the "Miscellaneous Technical" block, with code points 23FB-FE, with the exception of U+2B58⭘HEAVY CIRCLE, which belongs to the "Miscellaneous Symbols and Arrows" block. [13]
The standby symbol, frequently seen on personal computers, is a popular icon among technology enthusiasts. It is often found emblazoned on fashion items including t-shirts and cuff-links. [14] It has also been used in corporate logos, such as for Gateway, Inc. (circa 2002), Staples, Inc. easytech, Exelon, Toggl and others, [2] as record sleeve art (Garbage's "Push It") and even as personal tattoos. In March 2010, the New York City health department announced they would be using it on condom wrappers. [15] The 2012 television series Revolution, set in a dystopian future in which "the power went out", as the opening narration puts it, stylized the second letter 'o' of its title as the standby symbol. The power symbol was a part of exhibition at MoMA. [16] In the anime Dimension W , Kyouma Mabuchi wears a Happi with the power symbol on his back. In the television series Sense8 , the hacktivist character Nomi has a tattoo of the power symbol behind her ear.
The symbol, rotated clockwise by 90 degrees so it looks like a capital G, becomes part of the logo for Channel 5's programme The Gadget Show.
On 15 October 2019, 786 employees of Volkswagen Group United Kingdom Limited formed the world's largest human power symbol at Millbrook Proving Ground. [17]
ASCII, an acronym for American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. ASCII has just 128 code points, of which only 95 are printable characters, which severely limit its scope. The set of available punctuation had significant impact on the syntax of computer languages and text markup. ASCII hugely influenced the design of character sets used by modern computers, including Unicode which has over a million code points, but the first 128 of these are the same as ASCII.
The International Electrotechnical Commission is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". IEC standards cover a vast range of technologies from power generation, transmission and distribution to home appliances and office equipment, semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine energy as well as many others. The IEC also manages four global conformity assessment systems that certify whether equipment, system or components conform to its international standards.
Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.
A checkbox is a graphical widget that allows the user to make a binary choice, i.e. a choice between one of two possible mutually exclusive options. For example, the user may have to answer 'yes' (checked) or 'no' on a simple yes/no question.
The zero-width non-joiner is a non-printing character used in the computerization of writing systems that make use of ligatures. When placed between two characters that would otherwise be connected into a ligature, a ZWNJ causes them to be printed in their final and initial forms, respectively. This is also an effect of a space character, but a ZWNJ is used when it is desirable to keep the characters closer together or to connect a word with its morpheme.
The Alt keyAlt on a computer keyboard is used to change (alternate) the function of other pressed keys. Thus, the Alt key is a modifier key, used in a similar fashion to the Shift key. For example, simply pressing A will type the letter 'a', but holding down the Alt key while pressing A will cause the computer to perform an Alt+A function, which varies from program to program. The international standard ISO/IEC 9995-2 calls it Alternate key. The key is located on either side of the space bar, but in non-US PC keyboard layouts, rather than a second Alt key, there is an 'Alt Gr' key to the right of the space bar. Both placements are in accordance with ISO/IEC 9995-2. With some keyboard mappings, the right Alt key can be reconfigured to function as an AltGr key although not engraved as such.
A graphical widget in a graphical user interface is an element of interaction, such as a button or a scroll bar. Controls are software components that a computer user interacts with through direct manipulation to read or edit information about an application. User interface libraries such as Windows Presentation Foundation, Qt, GTK, and Cocoa, contain a collection of controls and the logic to render these.
In electrical wiring, a light switch is a switch most commonly used to operate electric lights, permanently connected equipment, or electrical outlets. Portable lamps such as table lamps may have a light switch mounted on the socket, base, or in-line with the cord. Manually operated on/off switches may be substituted by dimmer switches that allow controlling the brightness of lamps as well as turning them on or off, time-controlled switches, occupancy-sensing switches, and remotely controlled switches and dimmers. Light switches are also found in flashlights, vehicles, and other devices.
Box-drawing characters, also known as line-drawing characters, are a form of semigraphics widely used in text user interfaces to draw various geometric frames and boxes. These characters are characterized by being designed to be connected horizontally and/or vertically with adjacent characters, which requires proper alignment. Box-drawing characters therefore typically only work well with monospaced fonts.
On computer keyboards, the Esc keyEsc is a key used to generate the escape character. The escape character, when sent from the keyboard to a computer, often is interpreted by software as "stop", "cancel" or "exit", and when sent from the computer to an external device marks the beginning of an escape sequence to specify operating modes or characteristics generally.
IEC 61850 is an international standard defining communication protocols for intelligent electronic devices at electrical substations. It is a part of the International Electrotechnical Commission's (IEC) Technical Committee 57 reference architecture for electric power systems. The abstract data models defined in IEC 61850 can be mapped to a number of protocols. Current mappings in the standard are to Manufacturing Message Specification (MMS), GOOSE [see section 3, Terms and definitions, term 3.65 on page 14], SV or SMV, and soon to web services. In the previous version of the standard, GOOSE stood for "Generic Object Oriented Substation Event", but this old definition is still very common in IEC 61850 documentation. These protocols can run over TCP/IP networks or substation LANs using high speed switched Ethernet to obtain the necessary response times below four milliseconds for protective relaying.
Sleep mode is a low power mode for electronic devices such as computers, televisions, and remote controlled devices. These modes save significantly on electrical consumption compared to leaving a device fully on and, upon resume, allow the user to avoid having to reissue instructions or to wait for a machine to boot. Many devices signify this power mode with a pulsed or red colored LED power light.
In Unicode, a Private Use Area (PUA) is a range of code points that, by definition, will not be assigned characters by the standard. Three private use areas are defined: one in the Basic Multilingual Plane, and one each in, and nearly covering, planes 15 and 16. They are intentionally left undefined so that third parties may assign their own characters without conflicting with Unicode Consortium assignments. Under the Unicode Stability Policy, the Private Use Areas will remain allocated for that purpose in all future Unicode versions.
An electronic symbol is a pictogram used to represent various electrical and electronic devices or functions, such as wires, batteries, resistors, and transistors, in a schematic diagram of an electrical or electronic circuit. These symbols are largely standardized internationally today, but may vary from country to country, or engineering discipline, based on traditional conventions.
Standby power, also called vampire power, vampire draw, phantom load, ghost load, or leaking electricity, refers to how electronic and electrical appliances consume electric power. At the same time, they are switched off or in standby mode. It only occurs because some devices claim to be "switched off" on the electronic interface but are in a different state. Switching off the plug or disconnecting it from the power point can completely solve the problem of standby power. Switching off the power point is effective enough; there is no need to disconnect all devices from the power-point. Some such devices offer user remote controls and digital clock features.
In computing, a Unicode symbol is a Unicode character which is not part of a script used to write a natural language, but is nonetheless available for use as part of a text.
KPS 9566 is a North Korean standard specifying a character encoding for the Chosŏn'gŭl (Hangul) writing system used for the Korean language. The edition of 1997 specified an ISO 2022-compliant 94×94 two-byte coded character set. Subsequent editions have added additional encoded characters outside of the 94×94 plane, in a manner comparable to UHC or GBK.
In computer networking, Energy-Efficient Ethernet (EEE) is a set of enhancements to twisted-pair, twinaxial, backplane, and optical fiber Ethernet physical-layer variants that reduce power consumption during periods of low data activity. The intention is to reduce power consumption by at least half, while retaining full compatibility with existing equipment.
In digital electronics, analogue electronics and entertainment, the user interface may include media controls, transport controls or player controls, to enact and change or adjust the process of video playback, audio playback, and alike. These controls are commonly depicted as widely known symbols found in a multitude of products, exemplifying what is known as dominant design.
A toggle switch is a graphical control element that allows the user to make a choice between two mutually exclusive states. Originally toggle switches were used primary in touchscreen-based user interfaces, but they have later become commonplace in desktop and web applications.
