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Light blue resistors with 5 band codes?

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royalmp2001

Jan 1, 1970
0
Hi everyone,
What are the light blue resistors? Metal film maybe?
I have some with bands:
Brown - Green - Black - Red - Brown that read 15K on my ohmmeter.
The fourth band confuses me - it is definitely red not orange - any
ideas why?
Oh, and there is a red spot that joins the red and the brown.

Similarly I have some 8.25K resistors that are:
Grey - Red - Green - Brown - Brown with a red dot joining the two
browns.
I'd expect the fourth band to be red not brown.

Also any idea who makes these?
Thanks
 
P

PeteS

Jan 1, 1970
0
royalmp2001 said:
Hi everyone,
What are the light blue resistors? Metal film maybe?
I have some with bands:
Brown - Green - Black - Red - Brown that read 15K on my ohmmeter.
The fourth band confuses me - it is definitely red not orange - any
ideas why?
Oh, and there is a red spot that joins the red and the brown.

Similarly I have some 8.25K resistors that are:
Grey - Red - Green - Brown - Brown with a red dot joining the two
browns.
I'd expect the fourth band to be red not brown.

Also any idea who makes these?
Thanks

1% resistors have 5 bands, not 4.

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:
8 2 5 x10^1 1%
8.25k, 1%

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

Cheers

PeteS
 
P

PeteS

Jan 1, 1970
0
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

Impmon

Jan 1, 1970
0
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.

Also wouldn't an all blue resistor indicate flame proof or something?
5 band 1% resistor are not common and usually are used by the
military.
 
D

Don Bruder

Jan 1, 1970
0
Impmon said:
Also wouldn't an all blue resistor indicate flame proof or something?

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.
 
P

Pooh Bear

Jan 1, 1970
0
royalmp2001 said:
Hi everyone,
What are the light blue resistors? Metal film maybe?
I have some with bands:
Brown - Green - Black - Red - Brown that read 15K on my ohmmeter.
The fourth band confuses me - it is definitely red not orange - any
ideas why?
Oh, and there is a red spot that joins the red and the brown.

Similarly I have some 8.25K resistors that are:
Grey - Red - Green - Brown - Brown with a red dot joining the two
browns.
I'd expect the fourth band to be red not brown.

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
 
P

Pooh Bear

Jan 1, 1970
0
Impmon said:
Also wouldn't an all blue resistor indicate flame proof or something?
5 band 1% resistor are not common and usually are used by the
military.

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
 
R

Rich Grise

Jan 1, 1970
0
Also wouldn't an all blue resistor indicate flame proof or something? 5
band 1% resistor are not common and usually are used by the military.

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
 
R

Rich Grise

Jan 1, 1970
0
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.

<AOL>
Me, Too!
</AOL>

Cheers!
Rich
 
R

Rich Grise

Jan 1, 1970
0
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.

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, <whatever the
5% color is>, and a 22K 1% would be red, red, black, red, <apparently
brown for 1%>.

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
 
P

PeteS

Jan 1, 1970
0
Impmon said:
Also wouldn't an all blue resistor indicate flame proof or something?
5 band 1% resistor are not common and usually are used by the
military.

I would differ here. I have worked at a number of places where we used
5 band (1% and 2%) resistors all over the place, back in the days I
still commonly used through hole parts.

Cheers

PeteS
 
I

Impmon

Jan 1, 1970
0
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, <whatever the
5% color is>, and a 22K 1% would be red, red, black, red, <apparently
brown for 1%>.

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%.
 
D

Dr. Anton T. Squeegee

Jan 1, 1970
0
Also wouldn't an all blue resistor indicate flame proof or something?
5 band 1% resistor are not common and usually are used by the
military.

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).

--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"
 
P

Pooh Bear

Jan 1, 1970
0
Rich said:
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, <whatever the
5% color is>, and a 22K 1% would be red, red, black, red, <apparently
brown for 1%>.

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? :)

Yup ! :)

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

Graham
 
P

Pooh Bear

Jan 1, 1970
0
Impmon said:
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%.

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

Graham
 
E

ehsjr

Jan 1, 1970
0
Pooh said:
Rich Grise wrote:




Yup ! :)

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

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

Rich Grise

Jan 1, 1970
0
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
 
E

ehsjr

Jan 1, 1970
0
Rich said:
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
 
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