The Kuartlotron - keantoken's simple error-correction superbuffer

[RCruz]

Must build this one ASAP

[sikahr]

* added additional pads for L1, hole 1 mm (18AWG), copper 2,1 mm


Kean, permission to post on Dirty?

[danielwritesbac]

Originally Posted by sikahr

Only cosmetic changes, if there are no compalints I'll post this to dirty tommorow...

For convenient build, can you do L1 with PCB traces?

[sikahr]

Yes I can

Anybody knows how much uH is this inductor?

Calculation is for 20x20mm=2.9uH and ours is 20x16mm, so I believe we are not very far from 2uH.

Please someone check this independently.

Calculator link: Planar spiral coil inductor calculator

[keantoken]

Originally Posted by sikahr

Kean, permission to post on Dirty?

Go ahead.

[AndrewT]

Originally Posted by sikahr

...........Anybody knows how much uH is this inductor?

Calculation is for 20x20mm=2.9uH and ours is 20x16mm, so I believe we are not very far from 2uH.

Please someone check this independently.

Calculator link: Planar spiral coil inductor calculator

the number of Turns and the Area enclosed within the "coil" are the two major factors affecting the inductance value.

I am not familiar with the calculation, nor the flat type of inductor, so this is off the top of my head:

The area inside the 20 by 16mm coil is similar to a 18 by 18mm coil.
If you input 18mm into the "square" calculator you should get a close approximation to what the calculator designer would expect.

A wire coil has inductance that depends on Turns and the effective diameter of the "wire group".
If the coil is not circular, i.e. it is puled out into an oval, or into rectangle, then the inductance drops. This drop would be because the non circular shape encloses a smaller Loop Area.
That is the same effect as your 18x18, compared to 20x16.

Does any of that make sense?

[Joshua_G]

Originally Posted by Joachim Gerhard

…
I compared the Calvin against the Kean. Well., Martina may be able to describe that better.
…

Hi Joachim,
Would you care to say which one you prefer, or a brief account of the differences between those 2 buffers?
Thank you.

[sikahr]

For flexibility I decided to put it this way:

* added pads for external L1 conected serial with internal L1.

This way you can use internal, external or both L1, just short one you dont want to use.

If nobody complaints this version is final.

Originally Posted by keantoken

Go ahead.

Many thanks Kean.

Originally Posted by AndrewT

Does any of that make sense?

Andrew, it makes perfect sense to me, but I really dont have knowledge to be sure, so I added "backup" plan with external L1, this way if internal is OK all is good, if not you can use external L1.

[sikahr]

PS How much current is expected through the L1? Internal L1 trace width is cca 8 mils.

Internal L1 aproximated calculated resistance is cca 1.3 ohm.

[RCruz]