TIGHTpak toroid winding technology

[sendler]

I was doing some surfing and came across this interesting technology.
http://powerelectronics.com/mag/508PET22.pdf

[pjp]

I can't imagine how impractical this must be.

How do they squish the wire ahead of time ? And if they are doing it while winding the toroid, how do they keep from damaging the insulation ?


I see they're selling it, so I guess it is practical ... http://www.actown.com/download/TIGHTpak_brochure.pdf

... and there is a patent: US 7154368 http://www.patentstorm.us/patents/71...scription.html

[stoc005]

I don't really see a need to pack the toroid with extra wire most of the time. A 20 uHy coil has 13-14 turns. The rather large toroid that the wiring will go on will usually easily accomodate all the required turns in a single layer, which is as it should be. The wire size should be increased until the number of turns fills the single layer on the chosen toroid form. You want to lower the DC resistance of the output toroid(s) so that the resistive losses are as small as possible.

[sendler]

Originally Posted by stoc005

I don't really see a need to pack the toroid with extra wire most of the time. A 20 uHy coil has 13-14 turns. The rather large toroid that the wiring will go on will usually easily accomodate all the required turns in a single layer, which is as it should be. The wire size should be increased until the number of turns fills the single layer on the chosen toroid form. You want to lower the DC resistance of the output toroid(s) so that the resistive losses are as small as possible.

You must be using some really heavy cores. The Micrometals T106-2 cores that are the most common Class D toroid cores require 31 turns to make it to 13uH. 20ga. wire barely fits.
.
T106-2

[stoc005]

Using a Ferroxcube TN26/11-3C20-A113 gapped toroid cores.
OD is 26 mm, ID in 13.5 mm. Height is 11.6 mm. At least 20 turns, single layer, of #16 wire will fit, I believe.
See their app. note on these cores at their website. Ferroxcube - ferrite cores, bobbins & accessories

What size is the Micrometals core?? Specifically the ID, which controls how many turns are possible, single layer.

[sendler]

Originally Posted by stoc005

Using a Ferroxcube TN26/11-3C20-A113 gapped toroid cores.
OD is 26 mm, ID in 13.5 mm. Height is 11.6 mm. At least 20 turns, single layer, of #16 wire will fit, I believe.
See their app. note on these cores at their website. Ferroxcube - ferrite cores, bobbins & accessories

What size is the Micrometals core?? Specifically the ID, which controls how many turns are possible, single layer.

The link to the T106 cores is right there in my last post. It barely holds 13uH of undersized wire. Nobody has the A113 ferroxcube cores so I ordered some TN23-4C65 to try in the mean time.