32 lines
1.7 KiB
Markdown
32 lines
1.7 KiB
Markdown
|
E-series defined in IEC 60063 are a widely accepted system of preferred
|
||
|
|
numbers for electronic components. Available values are approximately
|
||
|
|
equally spaced in a logarithmic scale. Although E-series are used for
|
||
|
|
Zener diodes, inductors and other components, this calculator is mainly
|
||
|
|
intended for resistors.
|
||
|
|
|
||
|
|
E12: 1,0 1,2 1,5 1,8 2,2 2,7 3,3 3,9 4,7 5,6 6,8 8,2
|
||
|
|
E6: 1,0 - 1,5 - 2,2 - 3,3 - 4,7 - 6,8 -
|
||
|
|
E3: 1,0 - - - 2,2 - - - 4,7 - - -
|
||
|
|
E1: 1,0 - - - - - - - - - - -
|
||
|
|
If your design requires any resistor value which is not readily available,
|
||
|
|
this calculator will find a combination of standard E-series components to
|
||
|
|
create it. You can enter the required resistance from 0,0025 to 4000 KOhm.
|
||
|
|
Solutions using 3 or 4 resistors are given if a better match can be found.
|
||
|
|
The 4R checkbox option will take longer to process is considered for the E12
|
||
|
|
series only. Optionally it is possible to exclude up to two additional
|
||
|
|
values from the solution for the reason of being not available. If a
|
||
|
|
E-series value is entered to the required input field, it is always excluded
|
||
|
|
from any solution as it is assumed that this value is unavailable.
|
||
|
|
|
||
|
|
Solutions are given in the following formats:
|
||
|
|
|
||
|
|
R1 + R2 +...+ Rn resistors in series
|
||
|
|
R1 | R2 |...| Rn resistors in parallel
|
||
|
|
R1 + (R2|R3)... any combination of the above
|
||
|
|
__Example:__ Voltage dividers, commonly used for 1:10 range selection
|
||
|
|
require resistor ratio values 1:9. Unfortunately the "9" is a value, what
|
||
|
|
is not even in the E192 series available. Deviation of 1% and more is yet
|
||
|
|
unacceptable for 8 bit accuracy. For a required resistor value of 9 KOhm,
|
||
|
|
the calculator suggests the E6 values 2k2 + 6k8 in series as a possible
|
||
|
|
exact solution.
|