Having to wind an inductor, I was advised to do it "Two in hand". I understand it means using two wires connected at both ends. Do I need the same amount of turns ? Is the inductance affected (same question) ? Why isn´t the result two inductors in parallel connection ?
4
-
2\$\begingroup\$ I've never heard that term. Are you possibly talking about bifilar windings? \$\endgroup\$– Olin LathropCommented Dec 11, 2012 at 12:59
-
\$\begingroup\$ I don´t think so. I was told the wires should be connected at both ends, and it had nothing to do with self inductance (but could be easier to wind and have a smaller resistance). \$\endgroup\$– YvesCommented Dec 11, 2012 at 13:03
-
\$\begingroup\$ "Two in hand" sounds like some idiom literally translated from another language, which of course doesn't work. \$\endgroup\$– Olin LathropCommented Dec 11, 2012 at 13:12
-
\$\begingroup\$ sounds like Litz wire if the wires are all tied together in parallel. \$\endgroup\$– akohlsmithCommented Feb 9, 2013 at 4:51
Add a comment
|
2 Answers
\$\begingroup\$
\$\endgroup\$
2
"Two in hand" means you have 2 wires in parallel when you wind. This doesn't necessarily mean they are wound at the same time in parallel, it could just mean as you say above that they are connected at both ends after they wind. This is very often done to aid in manufacturing so that they can wind with a lower gauge wire. If 18 gauge wire is too big for your manufacturing processes, you can go to 21 gauge wire, two in hand. I've seen low voltage motors that are wound 3 in hand and 4 in hand. The inductance and resistance aren't significantly affected. Yes, you would use the same number of turns.
-
2\$\begingroup\$ This technique is also use to improve copper utilization in presence of skin effect. \$\endgroup\$ Commented Dec 11, 2012 at 16:30
-
1\$\begingroup\$ It also improves so called "packing factor" - essentially the ratio of copper to air in a particular winding area. This is more about resistance and time constant management than manufacturing. \$\endgroup\$ Commented Dec 11, 2012 at 19:16
\$\begingroup\$
\$\endgroup\$
Not only does "two-in-hand" winding help with manageability of wire when winding, it also keeps the outside diameter of the winding as close to the inside diameter as possible while still exhibiting low resistance. This improves inductance by preventing stray field leakage caused both by the conductor itself being far from the core on one side, and by hard-to-wind thick wire not being as tight to the core as a smaller gauge might be when winding.
