Generating 48V@50mA from 5V for microphone phantom power...

J

Jaye Gallagher

Guest
Hi there,

I need to generate a fairly clean 48V at around 50mA to be used for phantom
power for up to four microphones. The source voltage I need to step up
somehow is the 5V output of a battery driven DC-DC step up. Whilst I've
looked around for parts and schematics for this, any help or comments would
be much appreciated.

Thanks,
Jaye.
 
On Tue, 28 Dec 2004 17:05:30 +1100, Jaye Gallagher wrote:

Hi there,

I need to generate a fairly clean 48V at around 50mA to be used for phantom
power for up to four microphones. The source voltage I need to step up
somehow is the 5V output of a battery driven DC-DC step up. Whilst I've
looked around for parts and schematics for this, any help or comments would
be much appreciated.
As long as you already have batteries, just get 5X 9V "transistor radio"
batteries and clip them in series. Voila! 45V painlessly! If 45V isn't
enough, 6 in series will give you 54V, which you could regulate down
to 48.

Good Luck!
Rich
 
Rich Grise wrote:

I need to generate a fairly clean 48V at around 50mA to be used for
phantom power for up to four microphones. The source voltage I need
to step up somehow is the 5V output of a battery driven DC-DC step
up. Whilst I've looked around for parts and schematics for this, any
help or comments would be much appreciated.

As long as you already have batteries, just get 5X 9V "transistor
radio" batteries and clip them in series. Voila! 45V painlessly! If
45V isn't enough, 6 in series will give you 54V, which you could
regulate down
to 48.

Good Luck!
Rich
Well, I'm hoping to use a single battery source for this device, as it's
supposed to be portable. Hence the requirement that the 48V be derived from
my existing 5V supply.

Thanks anyway, though,
Jaye.
 
John Woodgate wrote:

Well, I'm hoping to use a single battery source for this device, as
it's supposed to be portable. Hence the requirement that the 48V be
derived from my existing 5V supply.

But what is your actual *battery* voltage? It can't be 5 V. If you run
your 48 V converter directly from the battery you will get a much
higher efficiency overall.
Oh, if I could find a way to step the battery voltage (2.4V, two NiMh cells)
up to 48V, that'd be ideal, but all of the parts I've looked at so far seem
to have around 5V minimum input voltages.

Jaye.
 
On Tue, 28 Dec 2004 17:05:30 +1100, in sci.electronics.design "Jaye
Gallagher" <msjaye@removethis.msjaye.com> wrote:

Hi there,

I need to generate a fairly clean 48V at around 50mA to be used for phantom
power for up to four microphones. The source voltage I need to step up
somehow is the 5V output of a battery driven DC-DC step up. Whilst I've
looked around for parts and schematics for this, any help or comments would
be much appreciated.

Thanks,
Jaye.

the feeble phantom, bottom of the page
http://www.rycote.com/information/default.htm
gives a lot of P48 info




martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.
 
I think you need to be a little tighter on your design spec. But in any
case
here is a component that can step up 3.1 volts to 48V
http://www.national.com/pf/LM/LM5000.html
 
Jaye Gallagher wrote:

Hi there,

I need to generate a fairly clean 48V at around 50mA to be used for phantom
power for up to four microphones. The source voltage I need to step up
somehow is the 5V output of a battery driven DC-DC step up. Whilst I've
looked around for parts and schematics for this, any help or comments would
be much appreciated.

Thanks,
Jaye.

Why pay the efficiency hit twice, one on the 5V switcher and one on the
phantom power supply? Why not just power the phantom supply straight
from the batteries?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
 
I read in sci.electronics.design that Tim Wescott
<tim@wescottnospamdesign.com> wrote (in <10t33ihl6ugkg02@corp.supernews.
com>) about 'Generating 48V@50mA from 5V for microphone phantom
power...', on Tue, 28 Dec 2004:

Where do you get your D-size NiMh cells?
I think 'Flag' size cells would be better!
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 

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