Light blue resistors with 5 band codes?

The sequence is

Digit 1, Digit 2, Digit 3, Multipler, Tolerance

(Unlike 5% or lower resistors that have only 2 digits identified).

Grey, Red, Green, Brown, Brown is:

A number of manufacturers make them. Try Vishay Dale, KAO-Speer and Bourns for starters.

Cheers

PeteS

Incidentally, the red spot joining the last bands is an orientation mark so you read it the right way around. The dot will be between the multipler and the tolerance band.

Cheers

PeteS

I've caught that bit of... information? scuttlebutt? urban legend? myself a few times through the years. Haven't ever found a definitive "That's reality" or "That's a crock" verdict on the concept, though. According to the way I've most often heard it, the "regular" resistors are just that - "regular" - Overload 'em, and they'll go up in smoke, possibly in literal flames as the carbon burns up. The pale blue ones are supposed to be non-flammable (They'll get hot and cook off if overloaded, but won't actually burst into flames, although they might get hot enough to touch off any flammable/explosive atmosphere surrounding them when they do) and the green ones are supposed to die without flames OR getting hot enough to ignite most flammable or explosive atmospheres they might be found in.

Also wouldn't an all blue resistor indicate flame proof or something?

I saw a lot of blue 5-band resistors in the military. I have no idea what the difference is, other than costing 10X as much as ordinary parts. ;-)

Cheers! Rich

Me, Too!

Cheers! Rich

I want to bring up semantics here. What do you mean by "the same multiplier"? It still is "the number of zeros after the other digits", isn't it? But it'll be one less than the 5% Rs, because of the other digit. For example, a 22K 5% would be red, red, orange, , and a 22K 1% would be red, red, black, red, .

So the properties of the multiplier are the same, it's just not the same numeric value because of the additional digit.

That's what you meant, right? :-)

Cheers! Rich

Resistors with 4 bands don't use the same multiplier as those with 3 bands 'cos there's an extra digit provided by the extra band.

Graham

Flame proof Rs are normally made with a 'cement' coating and it looks like it. Typically dull grey and a slightly rough surface finish.

Graham

I would differ here. I have worked at a number of places where we used

Cheers

PeteS

That is correct, the multiplier stays the same with both 4 and 5 band resistor. And FYI the 5% would be gold band. Silver is 10% and if you come across 3 band resistor, assume 20% tolerance. Red is 2 and brown is 1. I think there's also black for 0.5%.

I can't speak to the flame-proofing bit, but the last time I ordered regular commercial-grade 1% resistors from DigiKey, they had blue bodies and five color bands.

My point is that five-banders are likely much more common than you may have been led to understand.

Keep the peace(es).

Yup ! :-)

As in you might expect to see an orange band multiplier for a 47k but instead it's red.

Graham

Goodness. I can't even remember when I last saw a silver band.

Graham

Grumble. On the blue resistors I can't tell the difference between the colors, patricularly brown, red and orange. :-( Ed

If it's not a color-blindness issue, I've found that a 3X RS magnifying glass is very, very helpful. Our color receptors don't really have that fine of a resolution, but if the item is big enough to hit more than one or two cone cells, it should clear right up. :-)

Good Luck! Rich

Thanks! Gotta try that. Circuits don't work too well when you stuff a 470 in instead of a 47 K. Ed