The E series is a system of
preferred number
In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints.
Product developers must choose numerous lengths, distanc ...
s (also called preferred values) derived for use in
electronic component
An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are no ...
s. It consists of the E3, E6, E12, E24, E48, E96 and E192 series,
where the number after the 'E' designates the quantity of
logarithmic value "steps" per
decade
A decade () is a period of ten years. Decades may describe any ten-year period, such as those of a person's life, or refer to specific groupings of calendar years.
Usage
Any period of ten years is a "decade". For example, the statement that "du ...
. Although it is theoretically possible to produce components of any value, in practice the need for inventory simplification has led the industry to settle on the E series for
resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active e ...
s,
capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of ...
s,
inductor
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a c ...
s, and
zener diode
A Zener diode is a special type of diode designed to reliably allow current to flow "backwards" (inverted polarity) when a certain set reverse voltage, known as the ''Zener voltage'', is reached.
Zener diodes are manufactured with a great var ...
s. Other types of electrical components are either specified by the
Renard series
Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in ...
(for example
fuses) or are defined in relevant product standards (for example
IEC 60228 for wires).
History
During the
Golden Age of Radio
The Golden Age of Radio, also known as the old-time radio (OTR) era, was an era of radio in the United States where it was the dominant electronic home entertainment medium. It began with the birth of commercial radio broadcasting in the earl ...
(1920s to 1950s), numerous companies manufactured
AM radio
AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmis ...
receivers for consumer use. In the early years, many components were not standardized between radio manufacturers. The capacitance values of capacitors (previously called condensers)
and resistance values for resistors
were different than today.
In 1924, the
Radio Manufacturers Association
The Electronic Industries Alliance (EIA; until 1997 Electronic Industries Association) was an American standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the United States. They deve ...
(RMA) was formed by 50 radio manufacturers in
Chicago
(''City in a Garden''); I Will
, image_map =
, map_caption = Interactive Map of Chicago
, coordinates =
, coordinates_footnotes =
, subdivision_type = List of sovereign states, Count ...
to license and share patents. Over time, this group created some of the earliest standards for electronics components. In 1936, the RMA adopted a preferred number system for the resistance values of fixed composition resistors.
Over time, resistor manufacturers migrated from older resistance values to the 1936 resistance value standard.
American and British
military production during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
was a major influence for establishing common standards across many industries, especially in electronics, where it was essential to produce large quantities of standardized electronic parts very quickly for wireless communication and
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, Marine radar, ships, spacecraft, guided missiles, motor v ...
devices. Later, the
mid-20th century baby boom and the invention of the
transistor
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink).
A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
kicked off demand for
consumer electronics
Consumer electronics or home electronics are electronic ( analog or digital) equipment intended for everyday use, typically in private homes. Consumer electronics include devices used for entertainment, communications and recreation. Usuall ...
goods during the 1950s. As
transistor radio
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following the invention of the transistor in 1947—which revolutionized the field of consumer electronics by introducing small but powerful, convenient ...
production migrated towards Japan during the late-1950s, it was critical for the electronic industry to have international standards.
As worked on by the RMA,
the
International Electrotechnical Commission
The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and ...
(IEC) began work on an international standard in 1948.
The first version of this IEC Publication 63 (IEC 63) was released in 1952.
Later, IEC 63 was revised, amended, and renamed into the current version known as IEC 60063:2015.
IEC 60063 release history:
* IEC 63:1952 (aka IEC 60063:1952), first edition, published 1952-01-01.
* IEC 63:1963 (aka IEC 60063:1963), second edition, published 1963-01-01.
* IEC 63:1967/AMD1:1967 (aka IEC 60063:1967/AMD1:1967), first amendment of second edition, published 1967.
* IEC 63:1977/AMD2:1977 (aka IEC 60063:1977/AMD2:1977), second amendment of second edition, published 1977.
* IEC 60063:2015, third edition, published 2015-03-27.
Overview
The E series of preferred numbers was chosen such that when a component is manufactured it will end up in a range of roughly equally spaced values (
geometric progression
In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of non-zero numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the ''common ratio''. For ex ...
) on a
logarithmic scale
A logarithmic scale (or log scale) is a way of displaying numerical data over a very wide range of values in a compact way—typically the largest numbers in the data are hundreds or even thousands of times larger than the smallest numbers. Such a ...
. Each E series subdivides each
decade
A decade () is a period of ten years. Decades may describe any ten-year period, such as those of a person's life, or refer to specific groupings of calendar years.
Usage
Any period of ten years is a "decade". For example, the statement that "du ...
magnitude into steps of 3, 6, 12, 24, 48, 96, 192 values.
Subdivisions of E3 to E192 ensure the maximum error will be divided in the order of 40%, 20%, 10%, 5%, 2%, 1%, 0.5%. Also, the E192 series is used for 0.25% and 0.1% tolerance resistors.
Historically, the E series is split into two major groupings:
* E3, E6, E12, E24 — E3, E6, E12 are
subset
In mathematics, set ''A'' is a subset of a set ''B'' if all elements of ''A'' are also elements of ''B''; ''B'' is then a superset of ''A''. It is possible for ''A'' and ''B'' to be equal; if they are unequal, then ''A'' is a proper subset of ...
s of E24. Values in this group are rounded to 2
significant figures
Significant figures (also known as the significant digits, ''precision'' or ''resolution'') of a number in positional notation are digits in the number that are reliable and necessary to indicate the quantity of something.
If a number expres ...
.
* E48, E96, E192 – E48 and E96 are subsets of E192. Values in this group are rounded to 3 significant figures.
Since the electronic component industry established component values before standards discussions in the late-1940s, they decided that it wasn't practical to change the former established values. These older values were used to create the E6, E12, E24 series standard that was accepted in Paris in 1950 then published as IEC 63 in 1952. Eight of the E24 values do not match the following formula.
The formula for each value is determined by the
n-th root:
where
is the
rounded value,
is an
integer
An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign ( −1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the languag ...
of the E series group size, and
is an integer of
For E3 to E24, the values are rounded to 2 significant figures. For unknown historical reasons, eight older industry values (shown in bold) are different from the calculated values.
The eight official E24 values shown in bold do not exist in the E48, E96, E192 series.
For E48 to E192, the values are rounded to 3 significant figures.
* To calculate the E48 series:
is 48, then
is incremented from 0 to 47 through the formula.
* To calculate the E96 series:
is 96, then
is incremented from 0 to 95 through the formula.
* To calculate the E192 series:
is 192, then
is incremented from 0 to 191 through the formula, with one exception where 9.20 is official instead of calculated 9.19.
E3
The E3 series is rarely used,
except for some components with high variations like
electrolytic capacitor
An electrolytic capacitor is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor. A solid, liquid, or gel e ...
s, where the given
tolerance is often unbalanced between negative and positive such as or , or for components with uncritical values such as
pull-up resistor
In electronic logic circuits, a pull-up resistor (PU) or pull-down resistor (PD) is a resistor used to ensure a known state for a signal. It is typically used in combination with components such as switches and transistors, which physically int ...
s. The calculated constant tangential tolerance for this series gives ( − 1) ÷ ( + 1) = 36.60%, approximately. While the standard only specifies a tolerance greater than 20%, other sources indicate 40% or 50%. Currently, most electrolytic capacitors are manufactured with values in the E6 or E12 series, thus E3 series is mostly obsolete.
E24 vs. E48, E96, E192
Since some values in the E24 series do not exist in the E48, E96 and E192 series, resistor manufacturers have added the missing E24 values to of their 1%, 0.5%, 0.25%, 0.1% tolerance families. This allows easier purchasing migration between different tolerance parts. This type of combination is noted on resistor datasheets and webpages as "E96 + E24" and "E192 + E24".
;Comparison of E24 vs. E48 values:
:matching – 1.00, 1.10, 7.50
:missing – 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10
;Comparison of E24 vs. E96 values:
:matching – 1.00, 1.10, 1.30, 1.50, 2.00, 7.50
:missing – 1.20, 1.60, 1.80, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10.
;Comparison of E24 vs. E192 values:
:matching – 1.00, 1.10, 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.40, 4.70, 7.50
:missing – 2.20, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10
Examples
If a manufacturer sold resistors with all values in a range of 10
ohm
Ohm (symbol Ω) is a unit of electrical resistance named after Georg Ohm.
Ohm or OHM may also refer to:
People
* Georg Ohm (1789–1854), German physicist and namesake of the term ''ohm''
* Germán Ohm (born 1936), Mexican boxer
* Jörg Ohm (b ...
s to 10 megaohms, the available resistance values for E3 through E12 would be:
If a manufacturer sold capacitors with all values in a range of 10
pF to 1000 μF, the available capacitance values for E3 and E6 would be:
Lists
List of values for each E series:
;E3 values
: (40% tolerance)
: 1.0, 2.2, 4.7
;E6 values
: (20% tolerance)
: 1.0, 1.5, 2.2, 3.3, 4.7, 6.8
;E12 values
: (10% tolerance)
: 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2
;E24 values
: (5% tolerance)
: 1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1
;E48 values
: (2% tolerance)
: 1.00, 1.05, 1.10, 1.15, 1.21, 1.27, 1.33, 1.40, 1.47, 1.54, 1.62, 1.69, 1.78, 1.87, 1.96, 2.05, 2.15, 2.26, 2.37, 2.49, 2.61, 2.74, 2.87, 3.01, 3.16, 3.32, 3.48, 3.65, 3.83, 4.02, 4.22, 4.42, 4.64, 4.87, 5.11, 5.36, 5.62, 5.90, 6.19, 6.49, 6.81, 7.15, 7.50, 7.87, 8.25, 8.66, 9.09, 9.53
;E96 values
: (1% tolerance)
: 1.00, 1.02, 1.05, 1.07, 1.10, 1.13, 1.15, 1.18, 1.21, 1.24, 1.27, 1.30, 1.33, 1.37, 1.40, 1.43, 1.47, 1.50, 1.54, 1.58, 1.62, 1.65, 1.69, 1.74, 1.78, 1.82, 1.87, 1.91, 1.96, 2.00, 2.05, 2.10, 2.15, 2.21, 2.26, 2.32, 2.37, 2.43, 2.49, 2.55, 2.61, 2.67, 2.74, 2.80, 2.87, 2.94, 3.01, 3.09, 3.16, 3.24, 3.32, 3.40, 3.48, 3.57, 3.65, 3.74, 3.83, 3.92, 4.02, 4.12, 4.22, 4.32, 4.42, 4.53, 4.64, 4.75, 4.87, 4.99, 5.11, 5.23, 5.36, 5.49, 5.62, 5.76, 5.90, 6.04, 6.19, 6.34, 6.49, 6.65, 6.81, 6.98, 7.15, 7.32, 7.50, 7.68, 7.87, 8.06, 8.25, 8.45, 8.66, 8.87, 9.09, 9.31, 9.53, 9.76
;E192 values
: (0.5% and lower tolerance)
: 1.00, 1.01, 1.02, 1.04, 1.05, 1.06, 1.07, 1.09, 1.10, 1.11, 1.13, 1.14, 1.15, 1.17, 1.18, 1.20, 1.21, 1.23, 1.24, 1.26, 1.27, 1.29, 1.30, 1.32, 1.33, 1.35, 1.37, 1.38, 1.40, 1.42, 1.43, 1.45, 1.47, 1.49, 1.50, 1.52, 1.54, 1.56, 1.58, 1.60, 1.62, 1.64, 1.65, 1.67, 1.69, 1.72, 1.74, 1.76, 1.78, 1.80, 1.82, 1.84, 1.87, 1.89, 1.91, 1.93, 1.96, 1.98, 2.00, 2.03, 2.05, 2.08, 2.10, 2.13, 2.15, 2.18, 2.21, 2.23, 2.26, 2.29, 2.32, 2.34, 2.37, 2.40, 2.43, 2.46, 2.49, 2.52, 2.55, 2.58, 2.61, 2.64, 2.67, 2.71, 2.74, 2.77, 2.80, 2.84, 2.87, 2.91, 2.94, 2.98, 3.01, 3.05, 3.09, 3.12, 3.16, 3.20, 3.24, 3.28, 3.32, 3.36, 3.40, 3.44, 3.48, 3.52, 3.57, 3.61, 3.65, 3.70, 3.74, 3.79, 3.83, 3.88, 3.92, 3.97, 4.02, 4.07, 4.12, 4.17, 4.22, 4.27, 4.32, 4.37, 4.42, 4.48, 4.53, 4.59, 4.64, 4.70, 4.75, 4.81, 4.87, 4.93, 4.99, 5.05, 5.11, 5.17, 5.23, 5.30, 5.36, 5.42, 5.49, 5.56, 5.62, 5.69, 5.76, 5.83, 5.90, 5.97, 6.04, 6.12, 6.19, 6.26, 6.34, 6.42, 6.49, 6.57, 6.65, 6.73, 6.81, 6.90, 6.98, 7.06, 7.15, 7.23, 7.32, 7.41, 7.50, 7.59, 7.68, 7.77, 7.87, 7.96, 8.06, 8.16, 8.25, 8.35, 8.45, 8.56, 8.66, 8.76, 8.87, 8.98, 9.09, 9.20, 9.31, 9.42, 9.53, 9.65, 9.76, 9.88
Table
See also
*
Electronic color code
An electronic color code or electronic colour code (see spelling differences) is used to indicate the values or ratings of electronic components, usually for resistors, but also for capacitors, inductors, diodes and others. A separate code, the ...
– color-code used to indicate the values of axial electronic components, such as resistors, capacitors, inductors, diodes (also see
IEC 60062
The RKM code, also referred to as "letter and numeral code for resistance and capacitance values and tolerances", "letter and digit code for resistance and capacitance values and tolerances", or informally as "R notation" is a notation to specif ...
).
*
Geometric progression
In mathematics, a geometric progression, also known as a geometric sequence, is a sequence of non-zero numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the ''common ratio''. For e ...
*
Preferred number
In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints.
Product developers must choose numerous lengths, distance ...
*
Renard series
Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in ...
– used for current rating of electric fuses
*
Three-character marking code for resistors – for (E48/)E96 values (see EIA-96 and IEC 60062:2016)
*
Two-character marking code for capacitors – for (E3/E6/E12/)E24 values (see ANSI/EIA-198-D:1991, ANSI/EIA-198-1-E:1998, ANSI/EIA-198-1-F:2002 and IEC 60062:2016/AMD1:2019)
*
Notes
References
External links
![!StandardResistorValues](https://upload.wikimedia.org/wikipedia/commons/0/0b/%21StandardResistorValues.gif)
* Calculate the closest component value to any E-series with a
Excel User Defined Function
Calculate standard resistor values in Excel– EDN magazine
Printable E series tables
E6 to E96 Table– Servenger
E3 to E192 Table– Vishay
– Analog Services
{{List of IEC standards
Numbers
Industrial design
Logarithmic scales of measurement
es:Números_preferentes#Condensadores_y_resistencias