[Milsurplus] 12-24 vdc converters and toroid cores

[Mike Feher]

I admit that I have not been following thread, so, please take my comments
accordingly - About a week or so ago I purchased a 12 to 24 volt converter
from a guy in Israel on eBay. It arrived in good shape, and with connectors.
I believe this was intended for the RT-524, and, with shipping it was just a
little over $100. Have not tried it yet. He seems to have several. 73 - Mike

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960

  

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of Peter Gottlieb
Sent: Monday, October 05, 2009 7:17 PM
To: Michael Tauson
Cc: boatanchors at mailman.qth.net; milsurplus at mailman.qth.net;
boatanchors at lists.tempe.gov
Subject: Re: [Milsurplus] 12-24 vdc converters and toroid cores

Simplified:  the current times time during the magnetizing part of the 
waveform must not saturate the core.  Raising the frequency reduces 
that, but core losses can increase depending on core material.

You can monitor the primary current to watch for saturation by using 
either a current probe or a series small value non-inductive resistor.

Peter


Michael Tauson wrote:
> Most civilized civilian vehicles have 12 volt electrical systems these
> days.  Much of the surplus I'd like to use aboard my all to civilized
> Jeep requires 24vdc.  Building a small but mighty astable
> multivibrator to handle the primary and an appropriately wound
> secondary aren't a problem.  Where I do have a question or seventeen
> is core material - and size, for that matter.
>
> I know some materials are expressly for power transformers but is
> there any particular reason about any material can't be used for this
> application?  Frequency shouldn't be an issue but are there materials
> that might not like being in the presence of the currents that will be
> presented?  Aside from needing space to feed the wires through, are
> there any size requirements of note?
>
> I've read what I could find on the web.  Maybe the meds are messing me
> up (They do that, you know.) but I couldn't find anything that
> addressed these questions.
>
> ANy thoughts anyone?
>
> BEst regards,
>
> Michael, WH7HG
>   
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