science

Power symbol

Power symbol is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Power symbol rather than just read about it. In short: A power symbol is a symbol indicating that a control activates or deactivates a 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.

Key takeaways

Power symbol belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Power symbol to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Power symbol from memory before moving on to harder problems.

Reference excerpt

A power symbol is a symbol indicating that a control activates or deactivates a 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.

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.

Standards 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.

Unicode Because of widespread use of the power symbol, a campaign was launched by Terence Eden to add the set of characters to Unicode. In February 2015, the proposal was accepted by Unicode and the characters were included in Unicode 9.0. 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.

U+23FB ⏻ POWER SYMBOL (IEC 60417-5009 stand-by symbol, IEEE 1621 power symbol) U+23FC ⏼ POWER ON-OFF SYMBOL (IEC 60417-5010) U+23FD ⏽ POWER ON SYMBOL (IEC 60417-5007) U+2B58 ⭘ HEAVY CIRCLE (Used for IEC 60417-5008 power off symbol) U+23FE ⏾ POWER SLEEP SYMBOL

In popular culture

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. It has also been used in corporate logos, such as for Gateway, Inc. (circa 2002), Staples, Inc. easytech, Exelon, Toggl and others, 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. 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. On 15 October 2019, 786 employees of Volkswagen Group United Kingdom Limited formed the world's largest human power symbol at Millbrook Proving Ground.

See also List of international common standards Reset button

References

External links

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

Illustrations

Worked examples

Example 1 — a first encounter with Power symbol

Start with the simplest possible case. Write down what Power symbol claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Power symbol before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Power symbol ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Power symbol

In research: Power symbol appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Power symbol in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Power symbol is common in secondary-school and first-year university syllabi. It links to neighbouring topics IEC standards, IEEE standards, Pictograms, so understanding it makes those chapters shorter.
In everyday life: Look for Power symbol outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Power symbol in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Power symbol means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Power symbol out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Power symbol in simple terms?

Why does Power symbol matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Power symbol?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Power symbol.