JLN 2SGen solid state generator (like solid state orbo)

[Fraser]

I've been mucking around with a solid state orbo like device.

Having seen JLN do this, I decided to give it a go:
http://jnaudin.free.fr/2SGen/indexen.htm

I'll post the pics in posts below with a short descrip of each pic.

[Fraser]

I decided to make a toroid out of metglass to see how it performs, here you can see the finished toroid, underneath you can see my large coil of metglass. Too keep winds nice and tight; I've found it necessary to apply a little impact adhesive on the first foot of the wind. After winding the whole thing can then be wound real tight by forcing the outer wind in the direction of tightening and the centre stays solid.

[Fraser]

Th toroid needs at least 3 layers of PVC electrical tape to soften the very sharp edges and protect the magwire.

I constructed a nice rigid wooden threading shuttle to make winding as easy as possible, of course its still a pain to put several hundred wraps on a toroid.

[Fraser]

For the generator coil I used a 240V coil from an old fishtank airpump. It came with a U core, I cut it to an L core some time ago.

Below you can see the component parts of the whole sys. From left to right:
NeoMag,
Soft iron core,
generator coil,
magwire wrapped metglass toroid,
0.1ohm non inductive sampling resistor.

Bottom photo is the whole system assembled and running.

[Fraser]

Scope shots:
with 1x probes.
CH1 (top trace): voltage drop across 0.1omh input R.
CH2: Across output coil (with back to back LEDs in parallel)

pic [1]
Sinus into toroidal coil.

pic [2]
Square into toroidal coil.

[Fraser]

Just a few words about my observations so far:

[1]
I don't have near enough ampere-turns to saturate the toroid. I can't get close to making it drop a magnet when I apply DC power without overheating the coil. I will probably wrap it with alot more wire soon just to see if i can saturate this metglass.

[2]
Despite not saturating it I am of course seeing the toroid being able to redistribute an exterior field as it becomes energised.

[3]
As I load the generator coil I see absolutely no back coupling to the drive power.

[4]
My soft iron cored generator pickup is restricting my frequency range at the moment, it's only efficient below 150Hz.

[5]
I have no idea on efficiency as it stands, i suspect less than 10%, but I think efficiency can be greatly enhanced by:
many more turns on toroid and making a fine aircoil pickup loops that can rest top and bottom of toroid with small cylinder mag in the middle of toroid.

[6]
Toroid winding is a PAIN!

[darkspeed]

That really cool Fraser..

Get a stack of non magnetic shims and shim out the two until your existing windings allow it to loose attraction when energized.

This will give you a baseline on your winding, rather than just knowing    works / no work

[Fraser]

That really cool Fraser..

Get a stack of non magnetic shims and shim out the two until your existing windings allow it to loose attraction when energized.

This will give you a baseline on your winding, rather than just knowing    works / no work

Thats a good idea DarkSpeed, I will do that before and after increasing the turns on my existing toroid.

I´m thinking I might have to make another toroid with much less metglass so I can saturate it with less copper mass. I´d like to be able to go all the way to saturation to explore this fully and I don´t think I can get enough copper on my existing core to saturate it.

[darkspeed]

That is a lot of metglass

what are the specs on that material?

2000? 10000?

[Fraser]

Yes, it´s alot, it weighs alot, like a solid disk of iron, it was quite good value for the amount on the roll:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310201382762

I think its the high permeability stuff, which has DC permeability of 1000,000, yes you read it right... 1 Million!:

http://www.metglas.com/products/page5_1_2_6.htm

It handles like very thin spring steel, snapping when you really bend it tightly to a diameter of like 5mm.

I have just written to the seller to confirm the alloy type.

[darkspeed]

Freeow! your going to saturate that how? you may need like 1.5 turns of that metglass rather than a number of turns.

[Fraser]

Yes, I´m just realising the crazy amount of flux this relatively small toroid can contain before saturation. The old rule of thumb that says a transformer should have the same copper mass as core mass does NOT apply with metglas.

As you say much less material is needed, I´ll probably try 10 metglas wraps for a new toroid instead of the over a hundred I have on the one pictured.

[poynt99]

 

I'm not following these last few posts.

The less core material, the less magnetizing current required to saturate yes, but a higher permeability also results in less magnetizing current required to saturate (for an equal core mass), not more.

If you've not already done so, use a magnet and L-meter to check the coil inductance before and after magnet polarization. That should give you an idea what amp-turns (and/or core-turns) you need to affect the core to the degree you want.

.99