71885Re: Quick question about winding Transformers
- Jan 22, 2013Thanks so much for making these improvements to the build instructions! The algorithm may not be perfect but it's pretty darn impressive!
--- In firstname.lastname@example.org, "R. R. (Robby) Robson" wrote:
> I have modified the build instructions such that, in each step calling for
> the installation of an inductor, I print out an expanded winding
> instruction. For example, in the step calling for the installation of the
> T5 transformer in the RXTX
> Ensemble, the instruction is:
> XFRMR: 0.6uH: 14T/2x7T bifilar #30 on T25-6 (yellow) 8"
> Primary: Using approximately 9 inches of #30 wire, wind 14 turns on a T25-6
> (yellow) ferrite.
> Secondary: Using a total of 9 inches of #30 wire, wind 7 turns , bifilar,
> on the ferrite in the same direction as the primary winding. Inductance of
> the single winding (usually the primary) is 0.60 uH."
> The instructions are computer-generated and may have rounding errors in the
> computed wire lengths (e.g., in the above the shorthand version says 8";
> the generated version says 9"). I conservatively round up.
> If you are not seing this in the build instructions, please refresh the
> page in your browser (F5) to remove any cached older pages.
> I am open to suggestions as to how I should re-program the instruction
> generation algorithms for more clarity.
> Since I maintain this website and its associated infrastructure at no cost
> to the consumer of its instructions and receive no compensation for any of
> my labors or outlays, I am somewhat limited by my other commitments in my
> ability to respond as promptly as some might otherwise wish.
> On Mon, Jan 21, 2013 at 12:54 PM, Alan wrote:
> > **
> > ----- Original Message -----
> > Subject: [softrock40] Re: Quick question about winding Transformers
> > > I read that page several times before sending my first email, but it
> > does not deal with how to interpret this very cryptic
> > > statement:
> > >
> > > 0.69uH: 16T/2x8T bifilar #30 on T25-6 (yellow) 9" (top)
> > >
> > Joel,
> > As I've never followed Robby's instructions I'm not familiar with
> > following them But on the page I linked is:-
> > "Specification Format
> > Winding specs will generally resemble the following:
> > 5.0 uH 17T bifilar/34T #30 on T30-2 (red) (19").
> > This can be interpreted as:
> > a.. Use a T30-2 toroid (color is red and O.D. is 0.3")
> > b.. You will need two 19" lengths of #30 wire.
> > c.. For toroids, one turn is a single pass through the center hole.
> > d.. For binocular cores, one turn is a pass in which the wire goes in the
> > bottom, comes out the top, goes back in the other hole
> > at the top, and comes out the other hole at the bottom.
> > e.. The transformer will have a single, 34 turn, secondary winding of 19"
> > of #30 wire. Usually the single winiding is wound onto
> > the core first. Winding should be evenly spaced and ideally cover all but
> > a 15 degree "wedge" of the toroid. Sometimes, it may be
> > necessary to wind over the top of existing turns where there is more wire
> > than there is bare core left.
> > f.. The transformer will have two primary windings each of 17 turns of #30
> > wire. The term "bifilar" means to take one of the two
> > lengths of wire, bend it at the half-point so the resultant "hairpin" is
> > composed of the two 9.5" long halves, and then twist the
> > two strands together to make a "bifilar" strand with approximately 3
> > twists to the inch. The bifilar windings are usually wound
> > AFTER (and over) the single strand winding. You should wait until you have
> > wound it correctly before cutting the "hairpin" end of
> > the bifilar strand.
> > g.. The inductance value is provided primarily to help validate the number
> > of turns. It is the inductance of the single-strand
> > winding"
> > Which to me seems to give a reasonable idea. And the other links on that
> > page must give more information.
> > Once you have done one then it seems uneccessary to repeat the
> > instructions. It is a one-time learning procedure.
> > Many others have made the coils before with only a few asking about them.
> > However, if you feel Robby should make things clearer then I'm sure he
> > will be glad to discuss it with you.
> > 73 Alan G4ZFQ
> > >
> Richard R. (Robby) Robson
> LTC USA (RET)
- << Previous post in topic