lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« on: December 31, 2006, 09:20:12 AM »
I have been searching about this for a while, but seems quite dificult to find solutions.
  The best way to go supply a preamp from a battery without waste energy is using a smps.  But seems not easy to get one clean enough for good preamps. Although I´m pretty sure that can be done.  So I´ll pray God for a reply of any genius here to switch a light..  :roll:
Absent lake.


3nity

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #1 on: December 31, 2006, 10:48:24 AM »
I know that's possible, i EE engineer told me so! from a 48v with two 10k resistors in series beetween them you got 24v......the rest i don't remember.....
Life is a path, death the destination.

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #2 on: December 31, 2006, 02:15:50 PM »
I mean more going from less DC, for example, 12VDC or 18VDC. The reason is that is quite more easily to find a charger (I have one) to can charge a light battery pack like a NIMH one.
 Many comercial devices have this. Some acept variable input DC voltage from 6V to 16 V for example that make the devices suitable for most battery packs.
  I know that are IC that allow this, but the dificult is not to do it, the goal would be to do one as clean as would be a good designed linear one. And the perfect could be to can regulate the output to can be suitable for any preamp. For example, to +/- 24V,  +/-15V, +/- 18V etc.
  I suspect the this type of smps with high specs, low noise etc, require high knowlegde, if want to be aplied to any of the preamps DIY on the forum.
  would be nice to see more interested guys on this issue.
Absent lake.

Svart

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #3 on: December 31, 2006, 05:09:29 PM »
It's not easy to get perfect.  it's easy to get a working supply though.  check some of the IC datasheets for some designs.
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #4 on: December 31, 2006, 10:48:28 PM »
Quote from: "Svart"
It's not easy to get perfect.  it's easy to get a working supply though.  check some of the IC datasheets for some designs.


  I understand. But I suppose you neither consider a linear supply as perfect. Or do you?  
   Should I expect worse result with the smps one even with a good design?
Absent lake.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Well designed SMPS fron DC to get +/- 24 volt?
« Reply #5 on: January 01, 2007, 03:00:56 AM »
I used some standard DC-DC converters (5 V to +/-18 V) with good results for preamplifiers (and Rupert seems to do so as well in his new product line). A bit of filtering and sufficient care to PSRR of the amplifier might be wise though.

Application Note 70 from Linear Technology was recently posted by jdbakker and provides a good overview of what to expect when trying to design a low-noise (100 uV they claim) switching converter.

Samuel

CJ

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #6 on: January 01, 2007, 04:13:11 AM »
Anybody ever try a switcher out of a computer?
Seems to me that a zillion transistors working at 1 Giga would not like a bunch of noise floating around.
Sure would be cheap.

All kinds of voltages available too, +/- 5, +/- 12, +/- 24, +/-48, +/- 96, +/- 142, ...etc :?
If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #7 on: January 01, 2007, 11:23:10 AM »
Quote from: "CJ"
Anybody ever try a switcher out of a computer?
Seems to me that a zillion transistors working at 1 Giga would not like a bunch of noise floating around.
Sure would be cheap.

All kinds of voltages available too, +/- 5, +/- 12, +/- 24, +/-48, +/- 96, +/- 142, ...etc :?


 I didn´t understand what you mean...
Absent lake.

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #8 on: January 01, 2007, 11:26:53 AM »
Quote from: "Samuel Groner"
I used some standard DC-DC converters (5 V to +/-18 V)


 What do you refer to the IC, or to complete products?  I would prefer the way of  buying one, and modify then if required to improve it´s specs, rather than implemented it from zero.

Quote
Application Note 70 from Linear Technology was recently posted by jdbakker and provides a good overview of what to expect when trying to design a low-noise (100 uV they claim) switching converter.


 Have opened the pdf, and the first lines... "Jim Williams"  , it seems to have all answers to my doubts. Wherever forum I search for a specific issue, there is him with a reply. Seems a genius.
Absent lake.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Well designed SMPS fron DC to get +/- 24 volt?
« Reply #9 on: January 01, 2007, 12:29:42 PM »
Quote
What do you refer to the IC, or to complete products?

Complete product--IIRC from Traco Power. Very simple to use, though not super-cheap.

Quote
"Jim Williams" , it seems to have all answers to my doubts.

There's much more online: www.linear.com/designtools/app_notes/index.jsp

No. 25, 30 and 101 might be of special interest for you.

Samuel


lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #10 on: January 01, 2007, 02:59:04 PM »
Quote
Complete product--IIRC from Traco Power. Very simple to use, though not super-cheap.


 Don´t see above +-15 on Traco web.
 How about specs?  as noiseless as supposed the www.linear.com chips?
 Is there no one built device of the LT1533?   To build them seems require a lot of time and knowledge to get a good result.
Absent lake.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Well designed SMPS fron DC to get +/- 24 volt?
« Reply #11 on: January 01, 2007, 03:16:55 PM »
Quote
Don´t see above +/-15 V on Traco web.

You're right, I used a +/-15 V.

That's what's inside the new Neve stuff: www.motien.com.tw (V7 in the PWM section)

Samuel

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #12 on: January 01, 2007, 07:19:31 PM »
Quote
That's what's inside the new Neve stuff: www.motien.com.tw (V7 in the PWM section)

Samuel


 Seems ideal. I can´t find any price. I´ll write them, but I suspect will be no cheap. Anyways seems a good solution.
Absent lake.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Well designed SMPS fron DC to get +/- 24 volt?
« Reply #13 on: January 02, 2007, 01:59:52 AM »
Let us know if you were able to source them in small quantities--might need one as well sooner or later.

Samuel

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #14 on: January 03, 2007, 06:56:57 PM »
edited
Absent lake.

Samuel Groner

    Zürich, Switzerland
  • Posts: 2935
Well designed SMPS fron DC to get +/- 24 volt?
« Reply #15 on: January 05, 2007, 04:10:03 AM »
Quote
I think that the Neve preamps are made more for get an specific color, than for a clinical noise/floor ratio.

They're used in the Rupert Neve Portico, not the reissue stuff of AMS Neve.

Samuel

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #16 on: January 06, 2007, 07:35:18 AM »
edited
Absent lake.

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #17 on: April 01, 2007, 08:09:30 PM »
I got no reply from Motien. I have writed again just now.
  I´m still interested on this issue. I´m planning to build a green pre Dc powered.  Any suggestion would be thanked.
Absent lake.

Jonkan

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #18 on: April 02, 2007, 06:10:48 AM »
I think Jlm audio sell 48v smps that they use for their preamps if you can live with an exernal psu. They also have a product (in beta still) that allows you to get +-24v from said supply quite easily.

/j

lagoausente

Well designed SMPS fron DC to get +/- 24 volt?
« Reply #19 on: April 02, 2007, 06:11:58 PM »
Quote from: "Jonkan"
I think Jlm audio sell 48v smps that they use for their preamps if you can live with an exernal psu. They also have a product (in beta still) that allows you to get +-24v from said supply quite easily.

/j


 do you refer to the AC/DC psu?  I cannot see any DC-DC smps on JLM web...
Absent lake.


 

Related Topics

  Subject / Started by Replies Last post
12 Replies
2050 Views
Last post August 22, 2012, 07:29:32 AM
by trobbins
9 Replies
2158 Views
Last post December 03, 2012, 11:08:17 AM
by JanusRec
0 Replies
233 Views
Last post April 14, 2020, 05:53:29 PM
by HarmonyUnited
9 Replies
255 Views
Last post May 09, 2020, 05:18:47 PM
by moamps