The E-series is a system of preferred numbers used with electronic components such as resistors and capacitors. For example, the E6 series contains six values (10, 15, 22, 33, 47, 68) which cover a one-order of magnitude range of values (one decade) from 10 to 99. These base values repeat again to cover the next decade from 100 to 999, as 100, 220, 330, 470, and 680.
This eseries library is useful for selecting values from the
standard E3, E6, E12, E24, E48, E96 and E192 decades.
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The eseries package is available on the Python Package Index (PyPI):
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The package supports Python 3 and is compatible to Python 2.7. To install::
$ pip install eseries
For full help::
import eseries help(eseries)
In the meantime, here are some highlights.
To find the nearest E24 value to 319 use::
from eseries import find_nearest, E24 find_nearest(E24, 319) 330
To find the next value greater-than or equal-to 184 in the E96 series use::
from eseries import find_greater_than_or_equal, E96 find_greater_than_or_equal(E96, 184) 187
To find a few values around the specified value, use::
from eseries import find_nearest_few, E24 find_nearest_few(E24, 5000) (4700, 5100, 5600)
There's also a handy command-line interface. Run eseries --help
to see a list of commands::
$ eseries --help eseries
Usage: eseries [options]
Options: -h --help Show this screen. -v --verbose Use verbose logging
Available commands: ge gt help le lower-tolerance-limit lt nearby nearest range series tolerance tolerance-limits upper-tolerance-limit
See 'eseries help
To find a nearby value, use::
$ eseries nearest E24 37726 39e3
If you prefer an SI exponent symbol, supply --symbol or -s::
$ eseries nearest E24 37726 -s 39 k
To show values around the given value, use the nearby command::
$ eseries nearby E48 52e6 -s 48.7 M 51.1 M 53.6 M
To show the smallest value greater than or equal to the given value, use the ge command::
$ eseries ge E48 52e3 -s 53.6 k
To show the upper and lower tolerance limits of a nominal value, use the tolerance-limits command::
$ eseries tolerance-limits E48 35 34.3 35.7
To show all values in an inclusive range, use the range command::
$ eseries range E6 74e-9 34e-6 --symbol 100 n 150 n 220 n 330 n 470 n 680 n 1 µ 1.5 µ 2.2 µ 3.3 µ 4.7 µ 6.8 µ 10 µ 15 µ 22 µ 33 µ
Testing is performed for all supported versions using tox. You'll need to ensure that the required
Python versions are available in your environment. For example, if you're using pyenv, do::
$ pyenv local 2.7 3.6 3.7 3.8 3.9 3.10 3.11 3.12
before running tox::
$ tox
::
$ pip install -e ".[dev]"
$ bumpversion patch
$ python setup.py sdist bdist_wheel
$ twine upload --config-file