Groups > sci.electronics.design > #452053

Re: Choke winding question

From	rickman <gnuarm@gmail.com>
Newsgroups	sci.electronics.design
Subject	Re: Choke winding question
Date	2017-03-15 21:41 -0400
Organization	A noiseless patient Spider
Message-ID	<oacqae$tpn$1@dont-email.me> (permalink)
References	<oabn87$5ag$1@dont-email.me> <oacdfp$o29$1@dont-email.me> <oacegr030fg@drn.newsguy.com> <oacivp$cm5$1@dont-email.me>

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On 3/15/2017 7:36 PM, Clive Arthur wrote:
> On 15/03/2017 22:16, Winfield Hill wrote:
>> Clive Arthur wrote...
>>>
>>  What frequency are you choking?
>>
>>
> 10kHz to 100kHz.
>
> But my question is simpler, I probably haven't explained it well.  When
> I use a manufacturers PC software to see what's the most inductance I
> can get from an RM12 core with 2.5A DC going through it without it
> saturating, accepting that I will need multiple chokes in series to
> attain 5mH, it seems that the /total/ number of turns required is much
> the same.  Is that physics or just luck?
>
> According to the Ferroxcube software, a 400nH core with 57 turns giving
> 1.3mH saturates at 2.5A, so to get 5mH I'd need 4 of these, giving 228
> total turns for 5.2mH or 22uH/T
>
> 250nH, 89T, 2.5A, 2mH, 3 needed, 267T for 6mH or 22uH/T
>
> 1000nH core, 22T, 2.5A, 500uH, 10 needed, 220T for 5mH  or 23uH/T
>
> All the same core material, 3 different gaps for 3 different Al figures.
>
> It seems suspicious that these three configurations come up with the
> same total number of turns for the same inductance at the same
> saturation current.  Is this something simple which is well known in the
> choke-winding fraternity, is it coincidence, or is it an inevitable
> consequence of inductor physics?  It may well be an obvious thing which
> I simply didn't know.

What is different about the cores that give them the different ratings? 
Is it size, materials, what?  Are the winding dimensions the same?  What 
is the same vs. what is different?

-- 

Rick C

Thread

Choke winding question Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-03-15 15:42 +0000
  Re: Choke winding question Winfield Hill <hill@rowland.harvard.edu> - 2017-03-15 09:48 -0700
    Re: Choke winding question Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-03-15 17:03 +0000
  Re: Choke winding question John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-15 10:29 -0700
    Re: Choke winding question Winfield Hill <hill@rowland.harvard.edu> - 2017-03-15 11:37 -0700
    Re: Choke winding question Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-03-15 22:02 +0000
      Re: Choke winding question Winfield Hill <hill@rowland.harvard.edu> - 2017-03-15 15:16 -0700
        Re: Choke winding question Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-03-15 23:36 +0000
          Re: Choke winding question rickman <gnuarm@gmail.com> - 2017-03-15 21:41 -0400
            Re: Choke winding question Phil Allison <pallison49@gmail.com> - 2017-03-15 19:28 -0700
            Re: Choke winding question bill.sloman@ieee.org - 2017-03-15 20:12 -0700
              Re: Choke winding question rickman <gnuarm@gmail.com> - 2017-03-16 00:00 -0400
                Re: Choke winding question Clive Arthur <cliveta@nowaytoday.co.uk> - 2017-03-16 09:03 +0000
              Re: Choke winding question Winfield Hill <hill@rowland.harvard.edu> - 2017-03-16 05:56 -0700
                Re: Choke winding question bill.sloman@ieee.org - 2017-03-16 09:42 -0700
  Re: Choke winding question legg <legg@nospam.magma.ca> - 2017-03-15 19:23 -0400
  Re: Choke winding question "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-15 22:56 -0500
    Re: Choke winding question Phil Allison <pallison49@gmail.com> - 2017-03-15 22:30 -0700
      Re: Choke winding question "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-16 15:08 -0500

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