SV: Re: SV: RE: [sdiy] Multiple Voltage Power Supply / design problem!

[karl dalen]

Hmm, a charge pump, i wonder wouldn't a tiny 12V 1:1 transformer
with two secondary's feed by a 12V AC wall wart on single primary
be simpler and more efficient?

Alltought i have never seen such a transformer as a standard item from a 
component supplier.I suspect that those transformers are customer winded only.

KD 

--- mark verbos <mverbos at earthlink.net> skrev:

> Buchla's 200e is powered from a 12 volt wall wart with a DC-DC  
> converter to make the +/-15 volts and +5 volts. Actually, the 214  
> power supply used in the Music Easel was a DC-DC converter made from  
> discrete parts to take a 12 volt DC input from a big transformer or  
> Battery and convert it into +/- 24 then regulate that down to the +5  
> and +/-15.
> 
> I have reverse engineered this circuit if you want to see it....
> http://www.simple-answer.com/214_schem.jpg
> 
> Good luck getting the power transistors in there tho. You can use  
> some other big fat ones .
> 
> 
> 
> Mark
> 
> 
> 
> 
> On May 16, 2007, at 3:07 PM, John Luciani wrote:
> 
> > On 5/16/07, Roy J. Tellason <rtellason at verizon.net> wrote:
> >> On Wednesday 16 May 2007 13:27, Colin Hinz wrote:
> >> >  On Tue May 15 23:31 , "Roy J. Tellason"  sent:
> >> > >I had *one* UPS that wanted a total of _ten_ small batteries for
> >> > > replacement, as compared with typically one or two in the rest  
> >> of the
> >> > > ones that I've encountered.
> >> > >
> >> > >Too bad I can't seem to find any switchers which will accept a
> >> > > lower-voltage DC input.
> >> >
> >> > Roy,
> >> >
> >> > "Lower-voltage" means how low? And what sort of outputs are you  
> >> needing.
> >>
> >> No immediate needs,  instability of circumstances here precludes  
> >> me getting
> >> much going in the way of construction projects,  but it'd be neat  
> >> to be able
> >> to run things off 12V batteries or automotive power in general.
> >>
> >> Instead most of the switchers I run across seem to want line  
> >> voltage or double
> >> that.
> >
> > Vicor (www.vicr.com) has a wide range of DC-DC converters. For a 12V
> > input your options are limited to VI-20x or VI-2Vx series devices. If
> > you can wire your
> > batteries to get to the telecom range (48V) there are a wide range  
> > of options
> > including their 3rd generation of converters (V*I Chips) with
> > efficiencies above 90% and a
> > a power processing capability of 1000W/in^3.
> >
> > For low power designs where size is not crtical the Vicor converters
> > can be expensive. For
> > high power or dense layouts Vicor offers an excellent solution.
> >
> > (* jcl *)
> >
> > -- 
> > http://www.luciani.org
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



      _________________________________________________________
Ont om plats? Skaffa gratis Yahoo! Mail med obegränsat,
lagringsutrymme, kalender, virusscan och antispamfunktion.
http://se.mail.yahoo.com