dc-dc converter chip for phantom power

Archived from groups: rec.audio.pro (More info?)

Lawrence Lucier <llucier@shaw.ca> wrote:
>Howdy all......:-)
>
>Looking for recommendations for a dc-dc converter (12vdc input/48vdc
>output) integrated circuit so that I can roll my own portable phantom
>supply.
>
>Found one such beastie at:
>
>http://www.recom-international.com/html/euroline.htm
>RxxTR244872 In 5, 12 Out 24, 48, 72
>
>Any others that fit the bill? Thanks! :-)

There are plenty of them and they are all evil. I have used the shielded
ones from Endicott Research and they are okay for noncritical applications
where you can live with some RF trash. All of them are going to require
some extensive filtering on both the outputs AND the inputs.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Archived from groups: rec.audio.pro (More info?)

"Lawrence Lucier" <llucier@shaw.ca> wrote in message
news:F8bLc.63642$Mr4.39806@pd7tw1no
> Howdy all......:-)
>
> Looking for recommendations for a dc-dc converter (12vdc input/48vdc
> output) integrated circuit so that I can roll my own portable phantom
> supply.

You might want to take a look at the discrete-component alternatives:

One approach is to run a voltage multiplier off of an existing power
transformer winding,

http://sound.westhost.com/project96.htm

http://www.symetrixaudio.com/tech_ [...] 02_1A0.pdf

http://www.uneeda-audio.com/phantom/phan01.gif

the other is to use a switchmode multiplier running off of an existing DC
supply.

http://www.paia.com/tubehsch.pdf

http://www.rolls.com/data/pb224man.pdf

Archived from groups: rec.audio.pro (More info?)

On Wed, 21 Jul 2004 21:59:23 +1200, Geoff Wood <geoff@paf.co.nz-nospam>
wrote:
> martin griffith wrote:
>> On Tue, 20 Jul 2004 15:47:49 GMT, in rec.audio.pro you wrote:
>
>> LT1533 ultralow Noise1A Switching Regulator from linear.com
>> http://www.linear.com/pdf/1533f.pdf
>
> That's what's used in AKG PT pocket transmitters, FWIW.
>
> geoff
>
>

Any reason why you're not thinking linear instead of switching?

Archived from groups: rec.audio.pro (More info?)

On 21 Jul 2004 10:55:38 -0400, Scott Dorsey <kludge@panix.com> wrote:
> U-CDK_CHARLES\\Charles <cdkrug@aol.com> wrote:
>>On Wed, 21 Jul 2004 21:59:23 +1200, Geoff Wood <geoff@paf.co.nz-nospam>
>>wrote:
>>> martin griffith wrote:
>>>> On Tue, 20 Jul 2004 15:47:49 GMT, in rec.audio.pro you wrote:
>>>
>>>> LT1533 ultralow Noise1A Switching Regulator from linear.com
>>>> http://www.linear.com/pdf/1533f.pdf
>>>
>>> That's what's used in AKG PT pocket transmitters, FWIW.
>>
>>Any reason why you're not thinking linear instead of switching?
>
> If you are wanting to get 48V from a battery supply, you either need
> a lot of batteries or a switcher.
>
> Personally, I tend to go the route of using a lot of batteries.
> --scott

Oh BATTERY . .missed that. Four car batteries'd do it. Or perhaps
better four RV "Deep Cycle" batteries. Probably last four-five years.

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey <kludge@panix.com> wrote:

> If you are wanting to get 48V from a battery supply, you either need
> a lot of batteries or a switcher.

> Personally, I tend to go the route of using a lot of batteries.

How about a combination? Rechargeables fed by a dc-dc converter built
to less critical specs?

While 9v rechargeables still aren't good enough to handle most applications,
I would think that a low current demand like phantom power would be
do-able.

Rob R.

Archived from groups: rec.audio.pro (More info?)

Scott Dorsey <kludge@panix.com> wrote:

> Rob Reedijk <reedijk@hera.med.utoronto.ca> wrote:
> >Scott Dorsey <kludge@panix.com> wrote:
> >
> >> If you are wanting to get 48V from a battery supply, you either need
> >> a lot of batteries or a switcher.
> >
> >> Personally, I tend to go the route of using a lot of batteries.
> >
> >How about a combination? Rechargeables fed by a dc-dc converter built
> >to less critical specs?
>
> Maybe, but you're still carrying around a big box of batteries. In fact,
> since the current demand is so low, even cheap alkalines will last so long
> that it's not worth even worrying much about using rechargeables.

In that case, why not use one of those 67-volt camera batteries that
looks like a fat AA cell? They sell them at Batteries Plus and
probably Radio Shack. How long do you suppose one of those would last?

ulysses

Archived from groups: rec.audio.pro (More info?)

In article <290720042320335085%ulyssesnospam@rollmusic.com>, Justin Ulysses Morse <ulyssesnospam@rollmusic.com> wrote:
>Scott Dorsey <kludge@panix.com> wrote:
>
>> Rob Reedijk <reedijk@hera.med.utoronto.ca> wrote:
>> >Scott Dorsey <kludge@panix.com> wrote:
>> >
>> >> If you are wanting to get 48V from a battery supply, you either need
>> >> a lot of batteries or a switcher.
>> >
>> >> Personally, I tend to go the route of using a lot of batteries.
>> >
>> >How about a combination? Rechargeables fed by a dc-dc converter built
>> >to less critical specs?
>>
>> Maybe, but you're still carrying around a big box of batteries. In fact,
>> since the current demand is so low, even cheap alkalines will last so long
>> that it's not worth even worrying much about using rechargeables.
>
>In that case, why not use one of those 67-volt camera batteries that
>looks like a fat AA cell? They sell them at Batteries Plus and
>probably Radio Shack. How long do you suppose one of those would last?
>
>ulysses
Small 12v Gellcell batteries hooked together inseries 4x12 to equal your 48V
would do the trick