Electronic color code: Difference between revisions

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{{Use dmy dates|date=January 2020|cs1-dates=y}}

{{Use list-defined references|date=December 2021}}

[[Image:2.26 kilo-ohm precision resistor.jpg|thumb|upright|A {{val|22602.26|ul=ΩkΩ}}, 1%-precision resistor with 5 color bands ([[E96 series]]), from top, 2-2-6-1-1; the last two brown bands indicate the multiplier (×10) and the tolerance (1%).]]

An '''electronic color code''' or '''electronic colour code''' (see [[American and British English spelling differences#-our, -or|spelling differences]]) is used to indicate the values or ratings of electronic components, usually for [[resistor]]s, but also for [[capacitor]]s, [[inductor]]s, [[diode]]s and others. A separate code, the [[25-pair color code]], is used to identify wires in some [[telecommunicationtelecommunications]]s cables. Different codes are used for wire leads on devices such as transformers or in building wiring.

==History==

{{anchor|RMA|RTMA|RETMA|EIA|IEC}}

[[File:ResistorColorCodeGuide.jpg|thumb|[[Radio Manufacturers Association|RMA]] resistor color code guide, ca. 1945–1950]]

Before industry standards were established, each manufacturer used theirits own unique system for color coding or marking their components.

In the 1920s,{{Citation needed|date=November 2019|reason=Please help nail down the exact year of the RMA resistor color specification. It's in the range of 1924 to 1930.}} the '''RMA resistor color code''' was developed by the [[Radio Manufacturers Association]] (RMA) as a fixed resistor coloring code marking. In 1930, the first [[Radio receiver|radio]]s with RMA color-coded resistors were built.<ref name="ARH_1932_1"/><ref name="ARH_1932_2"/> Over many decades, as the organization name changed (RMA, RTMA, RETMA, [[Electronic Industries Alliance|EIA]])<ref name="JEDEC_EIA"/> so was the name of the code. Though known most recently as '''EIA color code''', the four name variations are found in books, magazines, catalogs, and other documents over more than {{Years ago|1930}} years.

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{{Further|List of electronic color code mnemonics}}

Useful [[mnemonic]]s have been created to make it easier to remember the numeric order of resistor color bands. The following example includes the tolerance codes gold, silver, and none:

* '''B'''ad '''B'''eer '''R'''ots '''O'''ut '''Y'''our '''G'''uts '''B'''ut '''V'''odka '''G'''oes '''W'''ell – '''G'''et '''S'''ome '''N'''ow.<ref name="Campbell_BUCD"/>

* '''B'''etty '''B'''rown '''R'''uns '''O'''ver '''Y'''our '''G'''arden '''B'''ut '''V'''iolet '''G'''ingerly '''W'''alks.

* '''B'''ad '''B'''ears '''R'''aid '''O'''ur '''Y'''ummy '''G'''rub '''B'''ut '''V'''eto '''G'''rey '''W'''affles.

* '''BB''' '''ROY''' from '''G'''reat '''B'''ritain has a '''V'''ery '''G'''ood '''W'''ife.

The following example includes the tolerance codes — gold, silver and none:

* '''B'''ad '''B'''eer '''R'''ots '''O'''ut '''Y'''our '''G'''uts '''B'''ut '''V'''odka '''G'''oes '''W'''ell – '''G'''et '''S'''ome '''N'''ow.<ref name="Campbell_BUCD"/>

The colors are sorted within ascending values in the order of thevisible light photon [[visible light spectrum|frequency/energy]] toolike in a rainbow to make them easy to remember and to reduce the significance of possible read errors due to color shifts and fading over time<!-- except for the tolerance ring -->: red (2), orange (3), yellow (4), green (5), blue (6), violet (7). Black (0) has no energy, brown (1) has a little more, white (9) has everything and grey (8) is like white, but less intense.<ref name="Clement"/>

=={{anchor|Capacitor code}}Capacitors==

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==Diodes==

The part number for small [[JEDEC]] "1N"-coded diodes—indiodes{{dash}}in the form "1N4148"—is{{dash}}is sometimes encoded as three or four rings in the standard color code, omitting the "1N" prefix. The [[1N4148 signal diode|1N4148]] would then be coded as yellow (4), brown (1), yellow (4), grey (8).

==Wire==

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Wires may be color-coded to identify their function, voltage class, polarity, phase or to identify the circuit in which they are used. The insulation of the wire may be solidly colored, or where more combinations are needed, one or two tracer stripes may be added. Some wiring color codes are set by national regulations, but often a color code is specific to a manufacturer or industry.

[[Building wiring]] under the US [[National Electrical Code]] and the [[Canadian Electrical Code]] is identified by colors to show energized and, neutral conductors, and grounding conductors, and to identify phases. Other color codes are used in the UK and other areas to identify building wiring or flexible cable wiring.

Mains electrical wiring, both in a building and on equipment, was once usually red for live, black for neutral, and green for earth, but this was changed as it was a hazard for color-blind people, who might confuse red and green; different countries use different conventions. Red and black are frequently used for positive and negative of battery or other single-voltage DC wiring.

[[Thermocouple]] wires and extension cables are identified by color code for the type of thermocouple; interchanging thermocouples with unsuitable extension wires destroys the accuracy of the measurement.

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==See also==

{{Commons category|Electronic color code}}

* [[E series of preferred numbers]] (IEC 60063) — {{dash}}series of preferred resistance and capacitance values

* [[Color code]]

* [[Electrical wiring]] — {{dash}}AC power wiring inside buildings, including standard color codes

==Notes==

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; Online resistor calculators

:* [http://www.resistorcalc.net Multi-purpose resistor code converter] (4 and 5 band, mobile-friendly, shows nearest standard value)

:* [httphttps://samstechlib.com/46436194/en/read/6_Band_Resistor_Color_Codes 6 band resistor color code calculator] (easy lookup, 4 and 5 band calculators also available)

; Historical charts

:* [https://stevenjohnson.com/cardboard/wheelcharts.htm Wheel charts]