[sdiy] basic transformer question

[Matthias.Herrmann at jeppesen.com]

hi derek,

that is absolutely fine. tie red and brown together for COM (0V or CT).

green blue will give you more than 40V when red and brown are tied 
together...

21V are normal when the transformer has no load... as soon as current is 
drawn from the transformer you will come closer to the 18V-0-18 or 36V 
respective.

cheers,
matthias
___
www.modular.fonik.de


synth-diy-bounces at dropmix.xs4all.nl wrote on 11/25/2008 02:31:42 PM:
> Hi folks,
> 
> I have a 1x230V/2x18V/30VA ring transformer, and my power supply board 
> calls for a center-tapped 36V trafo.  The board I'm working with is CGS 
> 66 PSU:
> 
> http://www.cgs.synth.net/modules/cgs66_psu.html
> 
> The color code of secondaries is as follows:
> 
> --------green
> |
> |
> --------red
> --------brown
> |
> |
> --------blue
> 
> The transformer isn't really behaving as predicted. I expected that 
> Green-Blue would give 36VAC or higher, however this is what I get:
> 
> Green-Red: 21V
> Green-Brown: 0V
> Green-Blue: 0V
> 
> Blue-Brown: 21V
> Blue-Red: 0v
> Blue-Green: 0V
> 
> Red-Brown: 0V
> 
> So my assumption is that Green and Blue might be out of phase, since 
> adding them together gives 0V instead of 36 or higher....
> 
> Is this still usable, if I wire Red & Brown to GND, Green & Blue to 18 
> VAC? Am I missing something simple here? Thanks in advance for reading 
> this admittedly n00b question, it's only that I don't want to blow 
> anything up!!!
> 
> Thx+best!
> Derek
> 
> 
> -- 
> derek holzer ::: http://www.umatic.nl ::: 
http://blog.myspace.com/macumbista
> ---Oblique Strategy # 40:
> "Decorate, decorate"
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