Electronic color code: Difference between revisions

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{{Short description|Color code to indicate values of electronic components}}

{{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.

In 1952, it was standardized in [[IEC 62:1952]] by the [[International Electrotechnical Commission]] (IEC) and since 1963 also published as '''EIA RS-279'''.<ref name="EIA_RS-279"/> Originally only meant to be used for fixed resistors, the color code was extended to also cover capacitors with [[IEC 62:1968]]. The code was adopted by many national standards like [[DIN 40825]] (1973), [[BS 1852]] (1974) and [[IS 8186]] (1976). The current international standard defining marking codes for resistors and capacitors is [[IEC 60062:2016]].<ref name="IEC_60062_2016"/> and [[EN 60062:2016]]. In addition to the color code, these standards define a letter and digit code named [[RKM code]] for resistors and capacitors.

Color bands were used because they were easily and cheaply printed on tiny components. However, there were drawbacks, especially for [[Color blindness|color blind]] people. Overheating of a component or dirt accumulation may make it impossible to distinguish brown from red or orange. Advances in printing technology have now made printed numbers more practical on small components. The values of components in [[surface mount]] packages are marked with printed alphanumeric codes instead of a color code.

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| The first significant figure of component value (left side)

| The second significant figure (some precision resistors have a third significant figure, and thus five bands).

| The decimal multiplier (number of trailing zeroes, or power of 10 multiplier)

| If present, indicates tolerance of value in percent (no band means 20%)

}}

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In the above example, a resistor with bands of red, violet, green, and gold has first digit 2 (red; see table below), second digit 7 (violet), followed by 5 (green) zeroes: {{val|2,700,000|u=ohms}}. Gold signifies that the tolerance is ±5%.

Precision resistors may be marked with a five band system, to include three significant digits, a power of 10 multiplier (number of trailing zeroes, and a tolerance band. An extra-wide first band indicates a wire-wound resistor.<ref>H. P. Westman (ed.), ''Reference Data for Radio Engineers, Fifth Edition'', ITT Howard W. Sams, Library of Congress 43-14665, pages 5-8 thorugh 5-10<name="Westman_1968"/ref>

[[File:Resistor Color Code.svg|alt=resistor color code|thumb|Resistor color code]]

Resistors manufactured for military use may also include a fifth band which indicates component failure rate ([[Reliability engineering|reliability]]); refer to [[MIL-HDBK]]-199<ref name="MIL_HDBK_199C"/> for further details.

Tight tolerance resistors may have three bands for significant figures rather than two, or an additional band indicating [[temperature coefficient of resistance]] (TCR), in units of [[parts per million|ppm]]/[[Kelvin|K]].

All coded components have at least two value bands and a multiplier; other bands are optional.

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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'''illyetty '''B'''rown '''R'''equiresuns '''O'''ftenver '''Y'''our '''G'''inarden '''B'''ut '''V'''aluesiolet '''G'''oodingerly '''W'''hiskey – '''G'''et '''S'''ome '''N'''owalks.

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

* '''BBB'''etty '''BROY'''rown '''R'''uns '''O'''ver '''Y'''ourfrom '''G'''ardenreat '''B'''utritain has a '''V'''ioletery '''G'''ingerlyood '''W'''alksife.

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]] like 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"/>

* '''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.

The colors are sorted with ascending values in the order of the [[visible light spectrum]] 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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! EIA/vibration [Hz]

|-

| style="background-color:#000000black" | &nbsp;

! Black

| 0 || 1 || — || — || — || −55 to +70 || 10 to 55

|-

| style="background-color:#964B00brown" |

! Brown

| 1 || 10 || ±1 || B || 100 || — || —

|-

| style="background-color:#FF0000red" |

! Red

| 2 || 100 || ±2 || C || — || −55 to +85 || —

|-

| style="background-color:#FFA500orange" |

! Orange

| 3 || {{val|1000|fmt=gaps}} || — || D || 300 || — || —

|-

| style="background-color:#FFFF00yellow" |

! Yellow

| 4 || {{val|10000}} || — || E || — || −55 to +125 || 10 to {{val|2000}}

|-

| style="background-color:#9ACD32green" |

! Green

| 5 || {{val|100000}} || ±0.5 || F || 500 || — || —

|-

| style="background-color:#6495EDblue" |

! Blue

| 6 || {{val|1000000}} || — || — || — || −55 to +150 || —

|-

| style="background-color:#9400D3violet" |

! Violet

| 7 || {{val|10000000}} || — || — || — || — || —

|-

| style="background-color:#A0A0A0grey" |

! Grey

| 8 || — || — || — || — || — || —

|-

| style="background-color:#FFFFFFwhite" |

! White

| 9 || — || — || — || — || — || [[Electronic Industries Alliance|EIA]]

|-

| style="background-color:#CFB53Bgold" |

! Gold

| — || — || ±5<ref group="nb" name="NB_Tolerance"/> || — || {{val|1000}} || — || —

|-

| style="background-color:#C0C0C0silver" |

! Silver

| — || — || ±10 || — || — || — || —

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=={{anchor|Inductor code}}Inductors==

Standards IEC&nbsp;60062&nbsp;/ EN&nbsp;60062 do not define a color code for [[inductor]]s, but manufacturers of small inductors use the resistor color code, typically encoding [[inductance]] in microhenries.<ref name="TDK_Inductors"/> A white tolerance ring may{{weaselis inline|date=Septemberused 2019}}by [[TDK]] to indicate custom specifications.<ref name="TDK_Inductors"/>

==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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<ref name="Antique_Resistor">{{cite web |title=The Antique Resistor Color Code |url=https://all-unique.com/PDF/Antique_Resistor_Color_Code.pdf |access-date=2016-12-19 |url-status=live |archive-url=https://web.archive.org/web/20161219160711/https://all-unique.com/PDF/Antique_Resistor_Color_Code.pdf |archive-date=2016-12-19}}</ref>

<ref name="ARRL77">{{cite book |editor-first=Tony |editor-last=Dorbuck |title=The Radio Amateur's Handbook |edition=5 |date=1978 |publisher=[[The American Radio Relay League]] |___location=Connecticut, USA |orig-year=1977 |id=no ISBN |lccn=41-3345 |pages=553–554}}</ref>

<ref name="Westman_1968">{{cite book |editor-first=H. P. |editor-last=Westman |title=Reference Data for Radio Engineers |date=1968 |edition=5 |publisher=[[International Telephone & Telegraph|ITT]] / [[Howard W. Sams]] |lccn=43-14665<!-- correct? --> |pages=5-8–5-10}}</ref>

}}

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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]