Primary Envy

[frackers]

Yup - I reckon stiff wire is easier to wind - the super flexible welding cable I have winds OK but it won't stay there!!

Here is the cable spec

Code: [Select]

DESCRIPTION: 50.0mmsq Plain Copper Wire Nitrile modified V90HT PVC Insulated.
 and sheathed single core 0.6/1KV to AS/NZS5000

CONDUCTOR: 1568 strands of 0.2 mm nom Plain Annealed Copper to
 AS/NZS1125 drawn from Class 110A copper to AS/NZS1574.
Max. D.C. resistance at 20C: 0.386 ohms / km

INSULATION: Coloured Nitrile modified P.V.C. type V90HT to AS/NZS3808
 Nominal Diameter: 12.0 mm
 Nominal Wall Thickness: 1.2 mm

I take it that the toroid would benefit from having the primary properly secured to the core but this stuff just bends back into a curve down the outside face - would I be best tying it down with baling string and then epoxy it? Not keen on starting something and it all going TU just as the epoxy cures ;(

[ClockmanFrance]

Yes, there are many types of cables, but perhaps I take it for granted what each type will do. In The Oztules book, A4 size 76pp 176 colour photos, I do explain about the different cables.

And the primary in my opinion should be the stiff, a few thick copper twisted strands, hook up wire, its also cheaper, but don't bash it to hard or the thin insulation just splits.

 Although 'oztules' mentions somewhere in his 'conversations' that the centre holding bolt and plate will keep the primary coils in place.

I go straight to Tri rated, multi stranded, welder, battery flex, very flexible cable, after the primary is done its last/first turn. 

[Pete]

Just a thought on the primary windings. As they are the high current parts it may be better to use wire that dumps the heat easier. Have you thought of getting either varnished copper or fibreglass insulated winding wire for the primary windings. We used to use very large CSA glass covered wire to wind coils in large motors and generators. The joins are easy to make, we used to silver solder them. Usually the square or rectangular section conductors are not varnished just covered in fibreglass sleeving that is varnished, so once the sleeving is removed at the ends there is very little varnish to scrape off.
Maybe it would not be worth it , but if heat in the primary windings is a problem that may be the way to go. Also the Glass insulation takes much more heat than PVC, more like 180 degrees rather than 90 degrees.
Anyway looks like you are having fun
Pete