Bank and ortho winding and capacitance and...

 :

9/12/2002 9:24 PM

R.G.

Bank and ortho winding and capacitance and... Still no ortho-porn, but nearest I remember, it involves moving the winding shuttle across the full winding width one or more times per turn, so that every turn traverses the entire width of the coil; the ratio of traverse to turn is non-integral so that each turns traverse starts at a slightly different place around the turn so that the winding looks like a progressive wave. I can't quite come up with the limits on the traverse cycle to turn cycle. Obviously, if the traverse is 1/(turns/layer), you get layer wound. If the traverse is 1/turn, you get a progressive wave winding, and if it's like two per layer you get a wavy, self supporting coil.     See   http://www.act1.com/app_fund.html     For some more definintive work on low self capacitance coils.     What this might involve is making up an auto traverse mechanism to feed wire onto the pickup with a definite traverse per cycle. It means giving up hand feeding, but that might be a relief     The old ?meteor? we had in the lab had a series of cams and such to adjust the traverse per turn.     R.G.

 

9/12/2002 11:04 PM

Dr. Strangelove

Careful on this one where Kaiser sez: quote: "Random wound cores utilizing 360º of the core yield the highest capacitances; 50 pF to 75 pF are typical values at 1,000 turns. Random wound cores utilizing 330º, sector-wound cores, and bank-wound cores all reduce the distributed capacitance."     Those comments refer to toroidal coils.     One interesting link on a Moebius winding pattern:   <http://www.electronics-tutorials.com/basics/mobius-winding.htm> Looks like it would bunch up in the middle, though.       There are fully automatic traverse mechanisms now, usually incorporated into $10k+ benchtop machines. I keep wondering how hard it would be to make one with a PIC controller and 30 oz/in stepper motor.     -drh   --

 

9/13/2002 12:04 AM

R.G.

PIC your poison quote: "There are fully automatic traverse mechanisms now, usually incorporated into $10k+ benchtop machines. I keep wondering how hard it would be to make one with a PIC controller and 30 oz/in stepper motor."   Not hard. There are packaged deals with PICs and steppers and lots of free sample code for PICs around.     Here's a thought: Hook a largish stepper to the bobbin as the major rotator for the bobbin. Hook a second, smaller stepper up to run the traverse by a leadscrew mechanism. Remember the bad-old-days dot matrix printers??? Those heads were stepper positioned. Gut one you find free. Or use 1/4-20 threaded rod and an adjustable nut.     Hmmm... Use the platen drive mechanism to do the rotation... hmmm...     Control both steppers by PIC. Feed the PIC serial information on what to wind from a PC. That way the PIC keeps track of how many turns and can adjust the lay of each turn under stepper control.     I have done some PIC controller stuff. Works nicely, and there are compilers to do the heavy programming lifting.     About here in any discussion of PICs someone pops in to note that "XYZ controller is better/faster/easier than PICs". Probably true. Any controller works. PICs are just an example.     R.G.

 

9/13/2002 1:58 PM

Dr Strangelove

RG wrote: quote: "About here in any discussion of PICs someone pops in to note that "XYZ controller is better/faster/easier than PICs". Probably true. Any controller works. PICs are just an example."     The best microcontroller for me should be easy to program, cheap, and handy -- in that order.     That said, Bagotronix.com's "DOS Stamp" isn't that cheap (~$200), but realtime programming for x86 DOS is a breeze.     -drh   --

 

9/13/2002 6:20 PM
R.G.	You can get     - PIC Basic Compiler ($100???)   - PICALL programmer ($60)       and program any of Microchips' PICs in basic. There are some free languages for PICs too.     There isn't any non real time programming that I know of for PICs.     R.G.

 

<<First Page

<Prev

Page 5 of 5