"N Cook" wrote in message
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Smitty Two wrote in message
news
In article ,
"N Cook" wrote:
Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...
"N Cook" wrote in message
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wrote in message
marked bands of red,yellow,yellow,gold, silver.
the third yellow band implies
Read your post. red, yellow,yellow,gold, silver. What third yellow
band?
If you're talking about the gold, that'd be the multiplier on a
5-band
resistor, or 10E-1. Silver is tolerance.
I read it as 24.4 at 10% tolerance, so 21.96-26.84.
Dave S.
alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,
it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are
only
10 percent tolerance?
--
We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.
But why a 2W 240K resistor in something that is unlikely ever to have more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.
Are you sure it's not the startup resistor, and not a fusible type at all ?
240k at a couple of watts is not unreasonable for a resistor in that
location, and they do go open for no apparent reason, but probably due to
voltage stress, as they do have about 350v across them in normal (UK)
operation. I've always assumed that they tend to use these 'bigger' rated
resistors, as they have a better working voltage rating, although sometimes,
you find two more conservatively rated resistors of 120k each, in series, to
double the voltage rating. You can easily tell if it is the startup
resistor, because one end of it will be connected directly to the "+"
terminal of the main filter cap, or the most "+" terminal if it uses two
stacked caps. Beware if it is an open startup resistor, as the main filter
cap(s) will remain fully charged ...
Arfa