rascalseven

Need help with bipolar 48v supply....?
« on: January 20, 2010, 06:37:09 PM »
I've been asked to rack up a bunch of ATI Paragon channelstrips, and the mic amp in these takes +/-48v.  LM337 tops out at -37v, and I've never needed this high a negative voltage before, so I'm not familiar with such designs.

Any ideas or direction?  ???

Thanks for any help you guys can send.

Peace,

JC
« Last Edit: January 20, 2010, 06:56:56 PM by rascalseven »
"If you dig the gig, do it. -But listen to the signal, not the person talking."  -Keef


volker

Re: Anyone got a good bipolar 48-volt supply design?
« Reply #1 on: January 20, 2010, 07:03:28 PM »
No, read the datasheet again. LM337, as well as LM317, can stand up to 40V (says NatSemi) DIFFERENCE between input and output, that is not the maximum output voltage. They would also happily regulate to 200V or whatever, as long as you don't go in too high.


Of course, if you want to go the discrete route: look for series/shunt voltage regulator.


Volker

Davo

Re: Need help with bipolar 48v supply....?
« Reply #2 on: January 20, 2010, 07:08:00 PM »
Nice, just learned somethin... cheers Volker

Eliani

Re: Need help with bipolar 48v supply....?
« Reply #3 on: December 31, 2016, 10:59:23 AM »
Did you ever end up racking the channelstrips? I just acquired 96 of them...  8)

Wel actually I bought two ATI Paragon 2 Consoles and want to make a test setup to power the channelstrips for when I need to do some work on them...
"Iron Projects" at Eli-Audio.com

Eliani

Re: Need help with bipolar 48v supply....?
« Reply #4 on: March 12, 2019, 07:07:47 AM »
Wel, if anybody would be interested, I did actually finish a PSU design for the ATI channel-strips...
And a custom wound transformer too by the way...

"Iron Projects" at Eli-Audio.com

pucho812

Re: Need help with bipolar 48v supply....?
« Reply #5 on: March 12, 2019, 07:11:15 PM »
wouldn't it be easier to just by a couple of OEM PSU's with floating output run them in series and connect common to ground to have a bipolar output?
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Eliani

Re: Need help with bipolar 48v supply....?
« Reply #6 on: May 12, 2019, 01:11:45 PM »
Pucho,

that's what I did for my first channelstrip, but I've got around 96 of these bad boys, and more coming soon. The benefit of a purpose built PSU will be gained in the long run.. ;-)
"Iron Projects" at Eli-Audio.com

Audio1Man

Re: Need help with bipolar 48v supply....?
« Reply #7 on: May 12, 2019, 05:38:41 PM »
Hi rascalseven
Food for though
People who use a 3 terminal voltage regulator where the input voltage is greater than the voltage limit of the part are fooling them self. It is like dropping a glass full of liquid onto a cement floor and hoping it will not spill or break.

While a floating 3 terminal voltage regulator will work, it will fail upon turn ON as the input is higher voltage and the load is Zero volts (exceeding the device voltage limit) until the capacitors charge up, overload or short circuit can produce failures.

A floating regulator need additional circuity to protect it upon turn ON, OVERLOAD or SHORT CIRCUIT. Why not design a real voltage regulator that won’t fail premature from the real operating systems.
Duke

benb

Re: Need help with bipolar 48v supply....?
« Reply #8 on: May 13, 2019, 12:40:46 AM »
I really like the idea of commercial/industrial off-the-shelf  (COTS) power supplies ("OEM PSUs").  Get two 48V linear open-frame supplies, maybe 2A or 5A output or whatever's available, put the outputs in series to make a +/= supply, and connect up as many channel strips as can be powered within the rated current output. Use as many sets like this as you need to power 'em all (do not connect power supply connections together between supplies, only the common ground!). There may be supplies available with all the current needed to run all strips, but they're likely to be SMPS, and for this kind of (line-level low-noise audio) application you probably really want linear supplies.

If you must design your own power supply, you're in luck, there's a very good electronics design book that has its power supply chapter available for free. Just click on "Download a sample chapter:"
https://artofelectronics.net/

But in this case I imagine even they would say "use a commercial power supply."

 

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