Amps
[Top] [All Lists]

Re: [Amps] Silly Inductor Question

To: Dan Levin <djl@andlev.com>
Subject: Re: [Amps] Silly Inductor Question
From: Angel Vilaseca <avilaseca@bluewin.ch>
Date: Tue, 08 Feb 2005 07:54:50 +0100
List-post: <mailto:amps@contesting.com>
Maybe you could stack 3 T-400A-2 cores

Angel HB9SLV

Dan Levin wrote:
> 
> Suppose that I want an inductor of 5 mH that will handle 1500 watts into a
> 3:1 SWR from 1.8 to 30 Mhz (to build an L network antenna tuner, at the
> output of a solid state amplifier, say).
> 
> 12 turns on a T-400A-2 powdered iron core will give me something like 5.2 uH
> at a maximum flux density of 70 gauss at 500 volts at 1.8 Mhz (with no DC
> current flowing).  70 gauss is acceptable at 1.8 Mhz (and it gets better
> relative to the spec as you get higher in frequency).  Fine, I'm a happy
> camper.
> 
> Now suppose that I want an inductor of .5 mH, all else the same.  4 turns on
> the same core gets me .58 mH, close enough - but the flux density is now
> 210, well beyond acceptable limits.  Things get worse for smaller inductors
> - the flux density goes through the roof for just 1 or 2 turns.
> 
> I can't buy a bigger core easily - so what do I do?  Is my only option an
> air core inductor (which I then have to shield...)?  It seems more likely
> that I am being dense, as usual :-)
> 
> Thanks!
> 
>                         ***dan, K6IF
> 
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps

_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>