MiscEl: Color codes

Back to MiscEl main page Write a message to author


This page can code and decode different color codes for electronic components. Many of these color codes are not used anymore, but may be needed for servicing old equipment.

The program can handle almost any component color code, and (when using "standard E value" settings) it will often detect (or prevent) entering the color codes backwards.

Most function can both code and decode the colors.

Input/output values

Colors are added by clicking on the colored bands, only "legal" colors will be visible.
If your make a mistake, use the arrow button to remove the last color from the component.

Conversion from specification to color codes are done on the input line. The values it will accept depends on the selected component, see the description under the specification field.

A few examples:

Resistor, standard E value: 5k 0.7% 30ppm
This will code a 4.99k 0.5% 25 ppm/K resistor, this is the closed standard value.
In the rigt pane some technical information will be show. How far the value is beside the requested value and what other standard values that can be used.

Resistor, standard E value: 17k 5%
With the 5% tolerance the low E values will be used and the result will be a 16k 5% resistor. Change the tolerance to 1% and it will code a precision resistor (16.9k 1%)

Capacitor, tantalum: 10u 10v
This will code an old style color coded tantalium capacitor with the specified value.

Inductor, standard E value: 9u 1% MIL
Coding will switch to MIL coding (First band is silver) for inductors. The nearest E value will be selected and coded.
The differens between requested and coded value will be shown, and a list of other E values that could be used.


Watch out for this message: Partial coding is misinterpreted, this means that the program did a bad job of coding your specification (i.e. the color codes are wrong). Try to change your specifications or complete them.

Using swapped colors the colors your have entered does only make sense if read backwards, check that your have entered the correct colors.


Hints