wire wound resistor

Discussion in 'General Electronics Chat' started by matty204359, Aug 27, 2012.

Apr 6, 2011
105
3
Does any body have an idea what kind of wattage this resistor can take? the wire appears to be about 16 gauge(the wire has a diameter of 1.01 mm according to my dial vernier) and has a resistance of 11 ohms. I don't know the length of the wire.

2. tracecom AAC Fanatic!

Apr 16, 2010
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Just guessing based on the physical size, I would say 100 watts or more. You can count the turns and measure the diameter to get a close idea of the total wire length. Then, you could use that with the total resistance to know the resistance per inch, and then correlate that to what the composition of the wire is, and then get a better idea of its rating.

What does the wire seem to be made of? Could it be nichrome? I wonder if it was built to use as a heating element.

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3. mik3 Senior Member

Feb 4, 2008
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I would say 500W for sure!

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4. cork_ie Member

Oct 8, 2011
348
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Looks like a cut down element from an electric heater.
These normally glowed bright red . They were about 14" long and 1KW.

while it would probably tolerate 500W
I would say c. 100W is more like the intended limit

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Apr 6, 2011
105
3
excellent, it will be a good dummy/test load! I don't know how to tell if its nichrome wire. I measured the diameter and it ranges from 1 3/8" - 1 7/16" because its not perfectly cylindrical. it has 61 turns with a circumference of 4 1/3" - 4 1/2". giving me a wire length of 264 1/3"(33.9 milliohms per an inch). - 275 1/2"(39.9 milliohms per an inch). Does anybody know what nichrome's resistance per an inch or foot is?

Last edited: Aug 27, 2012

Apr 6, 2011
105
3
sorry 18 gauge is the wire thinckness. I've tried google, I'm not having luck determining the resistance per foot/inch of 18 gauge nichrome wire.

7. tracecom AAC Fanatic!

Apr 16, 2010
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18 awg nichrome is .422 ohms per foot, which translates to .035 ohms per inch.

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Apr 6, 2011
105
3
that fits great with my estimated 33.9 -39.9 milliohms of resistance per an inch.

9. tracecom AAC Fanatic!

Apr 16, 2010
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So, it is quite likely 18 awg nichrome. I agree with cork_ie that it is part of a heating element that has been cut down for some special purpose - maybe a dummy load for something, or maybe a heating element for some specific voltage. Ohms law will tell you how much current it will conduct at various voltages.

10. #12 Expert

Nov 30, 2010
16,705
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You've probably realized that nichrome comes in different diameters for different purposes. In my clothes dryer, there are 2 diameters, one for 1800 watts and one for 5000 watts. I'm sure there are several more sizes.