gimmik capacitors and gimmik transformers

[robowaffe]

so gimmik capacitors are 2 stub wires twisted together.

and they are about 1 picofarad depending on how long they are.

A gimmik transformer would be 2 wires twisted together but using both ends of each side for a 1:1 isolation transformer.

What is the henries of a gimmik transformer?

[xavier60]

2.99e-8 H,
from this calculator, https://www.eeweb.com/tools/loop-inductance/

[robowaffe]

Thats much less than wire inductance.

But how come the diagram on that page only has 1 wire on it,  isnt there 2 wires in a transformer?

[xavier60]

Thats much less than wire inductance.

But how come the diagram on that page only has 1 wire on it,  isnt there 2 wires in a transformer?

It calculates the inductance of a single loop of wire. The inductance will be the same for each primary and secondary loop of a transformer.

[robowaffe]

So if u did around a 2cm iron coin?

[xavier60]

So if u did around a 2cm iron coin?

I don't know for certain, but I don't think it would work well due to core losses. One turn of that size on a ferrite core would work ok at low voltage at tens of KHz. It's difficult to be specific.

[robowaffe]

I don't need 100% power to go through,  but at least 50% would be nice.

So what are these core losses?   Or coin losses in this case?

Does that mean its the henries that go down,  or is it more indemic loss than that?

[xavier60]

I don't need 100% power to go through,  but at least 50% would be nice.

So what are these core losses?   Or coin losses in this case?

Does that mean its the henries that go down,  or is it more indemic loss than that?

I dont know enough to say anything too useful for now. Im expecting some 36mm ferrite pot cores to arrive soon for some experiments. I could report back then.

[robowaffe]

cool.     I looked it up, and core losses happen at higher voltages,  so if I do my system at low voltage its got a chance at workin'. 

Thanks for the information, Xavier60.

[Zero999]

It's flux density and frequency which affect core losses, not voltage.

[robowaffe]

that is the exact opposite of what I just read.   

that would mean it just lowers the Henry's!!!

[T3sl4co1l]

An iron coin would block field, at any frequencies where such a structure would be meaningful (100s MHz).  That is, it looks like a slug of moderate-resistance metal.

Bulk iron is a very poor core material at anything above DC.

A ferrite core might give reasonable function down to say 100s of kHz, depending on core size and circuit impedance.

Tim

[robowaffe]

Isn't the slower a transformer (hz wise) can function the better the material is?

[T3sl4co1l]

In a sense, perhaps. But there are many ways in which something can be "better", it's not a one-variable system.

Tim

[xavier60]

Second try,
This is an attempt at 1.5V into 1 turn on a 36mm PC40 pot core at 50KHz. The current waveform was measured across a 0.1Ω shunt, about 0.8A.
I calculate ~9uH. In a separate test, the core saturates at 5A.

From what arrived, the cores are sold in sets, https://www.aliexpress.com/item/1975838620.html?spm=a2g0o.productlist.main.1.2f401f8bMJBNPS&algo_pvid=55a5bf3e-5a17-44a1-8cfb-1350986a8ae7&algo_exp_id=55a5bf3e-5a17-44a1-8cfb-1350986a8ae7-0&pdp_npi=3%40dis%21AUD%213.06%213.06%21%21%212.02%21%21%402101f49816907717404235559e94f7%2112000026915788036%21sea%21AU%21130254308&curPageLogUid=9aSY9FuasQuY

[Terry Bites]

Get to grips with the transformer equation:

For sine wave transformer Bmax is the maximum allowed flux before core saturation.

E=4.44 f N A Bmax    pi()*sqrt(2) = 4.44

A =E/4.44 f N Bmax

A= cross sectional Area of core

E = emf

N=Turns

f= frequency

B= Flux density

[robowaffe]

So at 50 gigahertz, the transformer i need is a million times smaller than the one demonstrated here.