0.6 turn toroid?

[bianchi77]

Everyone,

I got a question for winding toroid :
I have
http://coil32.net/online-calculators...alculator.html
Please see the value on attachment,

How can I make 0.6 turn with 10cm wire ?

Cheers

[budm]

Re: 0.6 turn toroid?

359 nanoHenry?

[redwire]

Re: 0.6 turn toroid?

Your core has too high a permeability to create such a small value inductance 0.359uH and an air-core inductor would normally be used. That explains the under one turn.

That calculator is out to lunch on the required length of wire. The disclaimer is a bit odd "Wire length is calculated with a margin of 10 cm on the "ends".

[bianchi77]

Re: 0.6 turn toroid?

yes,
359 nanoHenry

if I reduce u = 160, it will be 2 turns....
The core I can find so far, u = 2300, can not find 160 yet...anyone knows ?

[PeteS in CA]

Re: 0.6 turn toroid?

Use a different material or maybe a different shape. E.G. use a ferrite rod instead of a ferrite toroid. Or use a ferrite E-core with a gap in it (use insulating paper). Or use something like Micrometals -26 or -52 powdered iron material, both of which have a u of 75. Or maybe -8, with a u of 35 and lower core loss than -26 or -52 above 100KHz.

[bianchi77]

Re: 0.6 turn toroid?

my frequency is 79.81KHz, where can I buy those core ? it will be like :
http://www.careful.cn/ferrite-rod-core/
I have some from death motherboard...

[bianchi77]

Re: 0.6 turn toroid?

I think it's similar with this :
https://www.aliexpress.com/store/pro...575015666.html

it's not exactly that but similar...
Do you reckon ?

[redwire]

Re: 0.6 turn toroid?

I would recheck the L value because it seems too small unless you are approaching microwave frequencies.
0.369uH at 79.81kHz the reactance is 0.185 ohm.

For filtering noise would be a much larger inductance 10-100uH.
VLF radio, lightning detection etc. your C value is too large and L too small in your tank circuit.

[budm]

Re: 0.6 turn toroid?

I would recheck the L value because it seems too small unless you are approaching microwave frequencies.
0.369uH at 79.81kHz the reactance is 0.185 ohm.

For filtering noise would be a much larger inductance 10-100uH.
VLF radio, lightning detection etc. your C value is too large and L too small in your tank circuit.

+1, I doubt that what he needs 0.369uH for 79KHz. Where did OP get that value from? What is the circuit you are working on?
"Free shipping 500pcs LH0406-3R3M 3.3uH 4*6mm 1.87 A Radial Leaded Power inductor 4x6mm" That is 3300 nanoHenry.

[PeteS in CA]

Re: 0.6 turn toroid?

b77, I'm not familiar with what sources for parts you have there in Oz. Micrometals seems to be available everywhere. It's based in Anaheim, California, but they have a factory in China plus a warehouse in Hong Kong. I suggest checking whether any distributors there in Australia carry Micrometals cores. Micrometals has catalog information on their website - materials and shapes.

I agree with redwire and budm. 369nH is an odd value for use at 79 KHz. Either there's a miscalculation somewhere (e.g. a decimal point moved 1 or 2 places) or it's being used to suppress noise in a frequency band much higher that 79 KHz.