Re: NEEDED: Color-code for carbon-film resistors- update

[david@uow.edu.au (David Wilson)]

Rubywand <rubywand@swbell.net> writes:
>and a couple other sources. None mentions a red tolerance band. However,
>a check through our resistor collection produced several with red for
>band 4 and all of these measured very close to the value indicated by
>bands 1-3.

>     All of the red tolerance resistors also had a 5th band (usually
>white) which, maybe, indicates temperature coefficient. Anyway, it looks
>like we are dealing with an extension of the old EIA code.

Five Band resistors are (in my experience anyway) high precision resistors:

Band	Meaning
1	Digit 1
2	Digit 2
3	Digit 3
4	Multiplier
5	Tolerance

My Dick Smith (Australian electronic retailer) catalog data section lists
Red as 2% and Brown as 1% tolerance.

The unfortunate side effect of adding another digit is that the multiplier
color changes. ie:

4 band 47kohm 5% = yellow purple orange gold
5 band 47kohm 5% = yellow purple black red gold

Some high voltage resisters use yellow as 5% to avoid problems with the
metal particles in gold paint compromising the voltage rating.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia  david@uow.edu.au