[ARC5] [Milsurplus] If You Need a Regulated Low B+ Supply

[Mike Feher]

Switching regulators are inherently isolated, unless, they make an effort to
connect the input common to the output common. I have never seen one like
that, which does not mean they do not exist, HI. 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 David Stinson
Sent: Friday, February 12, 2010 12:43 AM
To: 'Discussion of AN/ARC-5 military radio equipment.'; 'Old Tube Radios';
milsurplus at mailman.qth.net
Subject: Re: [Milsurplus] If You Need a Regulated Low B+ Supply

Some folks have asked where I got the converters.
It was a local surplus house in Carrolton, Texas,
called "Tanners."  We call it the "candy store."
Lots of good stuff but, alas, none of these remain in stock.
You find them often on Ebay.  Check with any local
surplus houses you know, because these kind of 
DC/DC converters are becoming pretty common.
You can get them for all kinds of voltages out.
If you look at some, be sure they have an isolated output
(i.e the input and output negatives are not common).
All of them I've seen in surplus are isolated, but some are not.
One caution:  Many of these can source better than an amp.
It's easy to look at these little bricks and think of 
safe, cute 12-volt plastic radios, and get careless.
When you start stacking them, 
they ain't "play-prettys" no more.
An amp at 300 volts will kill you mos'-very-buncha dead.
Be careful. 
73 Dave S.

p.s. I don't know if the case insulation will stand really high voltages,
since they were designed to never be more than 30 volts above ground.
I don't allow the cases to contact ground.  Haven't had a problem 
so far at the 90-volt level, but I've stacked them to 300 and 
I think that might be a bit "dicey."  I'm going to stick with 90 to 120 
volts and be happy.