Very interesting, thank you.

Is there an interactive simulator anywhere on the web where one can
experiment in realtime with inductors' design?

Cheers,
Mario


At 23.09 2011.08.04, you wrote:
>On 04/08/2011 19:58, Electron wrote:
>> Is an air core inductor of 1000 winds equivalent to an air core
>> inductor of 100 winds each on 10 layers?
>
>usually not.
>
>N squared is an approximation
>
>Short compared to diameter coils are different to coils long compared to=20
>diameter.
>
>Multilayer coils behave differently.
>
>PCB Spiral coils are "interesting" for 50MHz to 500MHz, but at higher=20
>frequencies  they don't work as imagined and length becomes dominant.
>
>Also Skin Effect varies with frequency. This has a major impact.
>
>Also multilayer has more complicated distributed self capacitance
>
>Here is an interesting air core coil
>
>http://www.techtir.ie/construction/herge-radio-base
>
>It's in 3 parts. Two coils are wound about 25 turns + 25 turns=20
>interleaved.. The 3rd coil is 5 turns separate to the side.
>
>If you put two completely separate air core coils (or any inductor) in=20
>parallel, then you get 1/2 inductance. Put them in series and you get=20
>double. But if the two coils are wound in parallel, then wiring them in=20
>parallel is just like having fatter wire. The Q is increased (resistance=20
>reduced to 1/2). The inductance remains the same as if there was one=20
>coil. Connect them in series, and it's like a flattened two layer coil,=20
>the inductance will be about x4
>
>The 3rd coil is used for positive feedback. As long as losses are=20
>greater than feedback, it doesn't oscillate. But as feedback is=20
>increased more of the coil losses are "cancelled" and the Q rises=20
>dramatically, and radio bandwidth is narrower. Just at the point of=20
>balance gives dramatic performance as if it was a perfect inductor.
>
>
>
>
>
>--=20
>http://www.piclist.com PIC/SX FAQ & list archive
>View/change your membership options at
>http://mailman.mit.edu/mailman/listinfo/piclist

--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.