In replacing a large can capacitor in my McIntosh C24 preamp, I burned out a 2.2k, 1w, carbon resistor that was attached to the old cap. It will be next week before I can get the correct part, but I'm very close (I think) to getting the unit operational and I don't want to wait for the part. I stopped by a Radio Shach and purchased two alternatives: 1) a 2.2k, 1/2 w carbon film, or 2) I can string together two 1k, 1w, plus two 100 ohm, 1w, medal oxide resistors. (1k + 1k + 100 + 100.) This would be a temporary fix until I get the right component.
I'd appreciate thoughts on which to use.
Thanks
I'd appreciate thoughts on which to use.
Thanks
1) No. McIntosh didn't use a 1 W resistor just for fun, so you're 1/2 W resistor might be overloaded.
2) Yes, this should work.
Since power is dissipated in four resistors instead of one, they might even be less than 1 W. For the 1k resistors, 1/2 W should suffice, for the 100R resistors 1/8 W is sufficient.
3) Yes, if the power the 2k2/1W resistor was designed to dissipate is somewhat less than 1 W (likely), this should work.
Because of tolerances, currents flowing through the parallelled resistors, aren't equal. Though, this is of little concern if the actual dissipation in the 2k2/1W resistor is not very close to 1 W.
2) Yes, this should work.
Since power is dissipated in four resistors instead of one, they might even be less than 1 W. For the 1k resistors, 1/2 W should suffice, for the 100R resistors 1/8 W is sufficient.
3) Yes, if the power the 2k2/1W resistor was designed to dissipate is somewhat less than 1 W (likely), this should work.
Because of tolerances, currents flowing through the parallelled resistors, aren't equal. Though, this is of little concern if the actual dissipation in the 2k2/1W resistor is not very close to 1 W.
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Appreciate all advice.
Wouldn't two 2.2k in series produce 4.4 ohms resistance?
Use option 3) two 2.2k 1/2W in series, paralleled with another two 2.2k in series.
Wouldn't two 2.2k in series produce 4.4 ohms resistance?
Appreciate all advice.
Wouldn't two 2.2k in series produce 4.4 ohms resistance?
yes you are correct.
but if you parrallel 2.2k with 2.2k both 1W you end up with a 1.1kohm 2W resisitor.
add the same up again and series and 2.2k higher wattage....
This reminds me of the; If you had a 5 and a 3 gallon bucket how do you measure out 4 gallons of water?
Not at all suggesting using a lesser rated part, but out of curiosity (because sometimes there are other constraints or desires) is it possible to post a partial schematic or sketch of how this 2.2K resistor is used?
Just re-read your original post where it seems possible this resistor is a bleeder across the large bulk cap, this would dissipate approximately half its rating for a 33V supply, or maybe its just part of a shunt regulator.
Many thanks
-Antonio
Not at all suggesting using a lesser rated part, but out of curiosity (because sometimes there are other constraints or desires) is it possible to post a partial schematic or sketch of how this 2.2K resistor is used?
Just re-read your original post where it seems possible this resistor is a bleeder across the large bulk cap, this would dissipate approximately half its rating for a 33V supply, or maybe its just part of a shunt regulator.
Many thanks
-Antonio
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T
Not at all suggesting using a lesser rated part, but out of curiosity (because sometimes there are other constraints or desires) is it possible to post a partial schematic or sketch of how this 2.2K resistor is used?
Just re-read your original post where it seems possible this resistor is a bleeder across the large bulk cap, this would dissipate approximately half its rating for a 33V supply, or maybe its just part of a shunt regulator.
Many thanks
-Antonio
It's R97.
thanks,
Attachments
2) Yes, this should work.
Since power is dissipated in four resistors instead of one, they might even be less than 1 W. For the 1k resistors, 1/2 W should suffice, for the 100R resistors 1/8 W is sufficient.
3) Yes, if the power the 2k2/1W resistor was designed to dissipate is somewhat less than 1 W (likely), this should work.
Because of tolerances, currents flowing through the parallelled resistors, aren't equal. Though, this is of little concern if the actual dissipation in the 2k2/1W resistor is not very close to 1 W.
Whoops... my remark in 3) about not being to close to 1 W is not applicable when 1/2 W resistors are being used. It would be in case of 1/4 W resistors.
The division of power dissipated I wrote about in 2) obviously also applies to 3).
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It's R97.
thanks,
Wanders, Thanks for the attachment.
Dont know what the actually current is but just based on the 1/16A fuse one would assume less than 12mA ( factor of 5 fuse derating). This would dissipate .32W if all is working correctly (so I would agree that a 1W seems reasonable).
Thanks
-Antonio
An externally hosted image should be here but it was not working when we last tested it.
It's a fast-blow type, some serial numbers have a solder-in pigtail type, others have a snap-in cartridge type.
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