W
Watson A.Name - \Watt Sun, the Dark Remover\
- Jan 1, 1970
- 0
I'm up to my tricks of winding 0.1 ohm resistors from some fine copper
wire and a resistor to wind it on. But I'm having trouble with the
wire, in more ways than one.
I've got a bobbin of realllly fine wire, I think the bobbin was from an
old clock motor. I measured the wire with a dial calipers and got .0025
inch, which according to my reference manual is 42 AWG, if it was bare
copper. But it's enemaeled, so I'd guess that it's the next smaller
common size, 44 AWG.
But I don't know how thick the enamel is, so I decided to wind a foot of
it onto a 1/8W resistor. The winding was a bit tedious, and I left a
quarter inch on each end for soldering it to the leads. I used my HP
3478A in four wire mode to measure it, and get a fairly accurate
reading. I get between 1.495 and 1.515 ohms after a few attempts,
depending on how much I warmed it up while handling it.
So I looked that up in the ref manual and it showd that it should be
between 41 and 42 AWG, closer to 42. I'm thinking that the reason why
it's lower than 1.66, which is 42, is because it's wire from a foreign
country where they use metric wire sizes. So I go online and Google for
metric wire sizes.
Well, after more than an hour, I gave up. I found many tables, most of
them don't go smaller than 40 AWG. And I can find AWG to metric
conversion, but what I'm really looking for is a chart of metric wire
sizes as they would be found in some reference manual, metric of course.
But no such luck. I found a site that claims that Litz wire has
performance between stranded and foil wire.
http://ldsg.snippets.org/appdx-el.php3 So if you want high performance
crossovers, use foil conductors. And here's the gummint specs for
direct burial and gopher resistant telephone cable, in case you're
interested.
http://www.usda.gov/rus/telecom/publications/html/1753f206.htm
I found that the metric gauge is ten times the wire size in mm. So if I
go by the conversion table, it would be a wire somewhere between .65 and
..7 metric gauges, which are actually .065 and .07 mm respectively, if
they even make such sizes. If I work backwards and say that it's 1.51
ohms per foot or 4.95 ohms per meter or 4950 ohms per kilometer, where
is there a chart that will allow me to look up the ohms per kilometer to
find the wire size? I can do it with AWG, but I don't see one for
metric wire sizes.
Thanks for any guidance.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
wire and a resistor to wind it on. But I'm having trouble with the
wire, in more ways than one.
I've got a bobbin of realllly fine wire, I think the bobbin was from an
old clock motor. I measured the wire with a dial calipers and got .0025
inch, which according to my reference manual is 42 AWG, if it was bare
copper. But it's enemaeled, so I'd guess that it's the next smaller
common size, 44 AWG.
But I don't know how thick the enamel is, so I decided to wind a foot of
it onto a 1/8W resistor. The winding was a bit tedious, and I left a
quarter inch on each end for soldering it to the leads. I used my HP
3478A in four wire mode to measure it, and get a fairly accurate
reading. I get between 1.495 and 1.515 ohms after a few attempts,
depending on how much I warmed it up while handling it.
So I looked that up in the ref manual and it showd that it should be
between 41 and 42 AWG, closer to 42. I'm thinking that the reason why
it's lower than 1.66, which is 42, is because it's wire from a foreign
country where they use metric wire sizes. So I go online and Google for
metric wire sizes.
Well, after more than an hour, I gave up. I found many tables, most of
them don't go smaller than 40 AWG. And I can find AWG to metric
conversion, but what I'm really looking for is a chart of metric wire
sizes as they would be found in some reference manual, metric of course.
But no such luck. I found a site that claims that Litz wire has
performance between stranded and foil wire.
http://ldsg.snippets.org/appdx-el.php3 So if you want high performance
crossovers, use foil conductors. And here's the gummint specs for
direct burial and gopher resistant telephone cable, in case you're
interested.
http://www.usda.gov/rus/telecom/publications/html/1753f206.htm
I found that the metric gauge is ten times the wire size in mm. So if I
go by the conversion table, it would be a wire somewhere between .65 and
..7 metric gauges, which are actually .065 and .07 mm respectively, if
they even make such sizes. If I work backwards and say that it's 1.51
ohms per foot or 4.95 ohms per meter or 4950 ohms per kilometer, where
is there a chart that will allow me to look up the ohms per kilometer to
find the wire size? I can do it with AWG, but I don't see one for
metric wire sizes.
Thanks for any guidance.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@