Go Tinman
Two thumbs up bro, good vid
Thanks for sharing

Tinman your inner windings are they wound as in fig.1 or fig.2

Figure 2-same as outer windings around the toroid core.
I am glad i finally done this build-->there is more to come,so keep watch.

Tinman your inner windings are they wound as in fig.1 or fig.2

I think his winding is equivalent to current loops shown in Fig.1 and Fig.2

Tinman,

Very interesting...

I hope you will make a video of the "drive one of the inner coils as a primary" test you mentioned.  That might prove interesting (with and without a load on the outer windings).

Did you happen to do any control experiments of the inner toroid and its windings before you applied the outer potting? 
Performing the "one winding of the inner coil as a primary test" before and after potting might prove interesting.

Any idea what specific ferrite material the inner core is made from?

Can you post the actual product/model number of the Devcon product you used?  A quick look indicated there are at least 4 different liquid or putty steel products in their lineup.  The link you provided says "steel putty" as opposed to their liquid steel products.  Was the product you used "putty" or "liquid"?

I wonder if molding a somewhat hollow two piece toroid that can be slipped over the inner toroid might produce similar results.  I recall someone doing something similar with toroid "hemispheres" welded together over an inner core (possibly someone with better memory than I can better recall that experiment).

Thanks for sharing...
PW   

Tinman,

Very interesting...





I wonder if molding a somewhat hollow two piece toroid that can be slipped over the inner toroid might produce similar results.  I recall someone doing something similar with toroid "hemispheres" welded together over an inner core (possibly someone with better memory than I can better recall that experiment).

Thanks for sharing...
PW   

I hope you will make a video of the "drive one of the inner coils as a primary" test you mentioned.  That might prove interesting (with and without a load on the outer windings).

I will be doing that and more today. I will post the video when done.

Did you happen to do any control experiments of the inner toroid and its windings before you applied the outer potting? 
Performing the "one winding of the inner coil as a primary test" before and after potting might prove interesting.

This is one thing i didnt do,and now wish i had done

Any idea what specific ferrite material the inner core is made from?

No idea. There were no numbers or writing on it at all. It was blue in color,and was from a high frequency tig welder circuit board.

Can you post the actual product/model number of the Devcon product you used?  A quick look indicated there are at least 4 different liquid or putty steel products in their lineup.  The link you provided says "steel putty" as opposed to their liquid steel products.  Was the product you used "putty" or "liquid"?

The product in the link is the one i used-steel putty. I just added some metholated spirit's to make it easy to pour. I am now experimenting with embedding resin/ferrite powder,and embedding resin/iron filings for core material.

It is ashame those pot cores dont have a bigger hole through the middle of them. You could wind a coil around a ferrite toroid core,place that in the pot core,then wind a coil around the pot core-->but im not sure the hole in the middle of the pot core would be big enough to feed all the wire through for the outer winding-but it maybe ,if you use a small gauge wire.
I might look into that today,so as others can do an easy build to try it out.

Tinman,

I was actually looking at pot cores prior to my post for that very reason (and considering diamond coated tooling and a bit of water cooling to enlarge the center hole a bit if needed).   

How well centered is your inner core within the outer molded core?  That is, do your inner windings end up being perfectly centered within the outer windings?

Also, could you post some dimensional info such as the OD/ID and thickness of the inner and outer cores?

Thanks...

PW

Tinman,

With regard to performing a test of the inner core prior to potting as a control, was that loose core you dropped in the video identical to the one you used in the potted core?

Did it survive being dropped?

PW

No-that core i dropped was much smaller. The inner core was-ID=36mm, OD=46mm, hight=12mm.
It is in the very center of the outer core.Will supply the outer core dimentions with next video-which is uploading now.