I have this 100Megaohm resistor, deep purple to brownish body. It is 100 megs since it divides 10V to 5V series with my 100Meg Multitester and so says also the colorcode: brown-black-purple-white
Now what is the White??? I have no source/reference that it even should exist in that place as a 4th band. I'm just curious.. Anyone have any information what is this presumaply nonstandard marking.
I have no idea of the age of this as it is salvaged part from random electronics in the past (late 90s when it did end to my box of resistors).
For very high values, which will often be used at high voltages, you don't want a metallic ink like gold or silver, so white is probably used as non-shiny silver.
These VR68 high-voltage resistors use yellow instead of gold
From the datasheet
http://www.vishay.com/docs/28907/vr25vr37vr68.pdfYellow and gray are used instead of gold and silver because metal particles in the lacquer could affect high-voltage properties.
Oh, really nice. Thx.
It might indeed be the explanation, since it does have good technical reasoning.
The resistor I have also do have this hard enamel shine on it so it might indeed be a highvoltage range. Something over the typical jellybean dip to paint range anyway.