[sdiy] Ground = -15V ????

[Rutger Vlek]

Hi everyone,

thanks. The problem is solved! A small piece of wire got trapped between the 
ground and the -15V. Not enough to cause the powersupply to detect a 
'short', but enough to make the ground -15V.

Thanks for the help!

Greetings,

Rutger


>From: René Schmitz <uzs159 at uni-bonn.de>
>To: Rutger Vlek <rutgervlek at hotmail.com>
>CC: Harald.Antes at t-online.de, synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] Ground = -15V ????
>Date: Sat, 07 Jan 2006 17:11:27 +0100
>
>Hi Rutger,
>
>Rutger Vlek wrote:
>>Hello everyone,
>>
>>I'm having a strange problem with a synth i'm building. It's just finished 
>>and works fine, but I found out that there's a voltage difference between 
>>the synths ground and the ground of my mixer. The difference is 15V!! 
>>That's exactly the voltage the powersupply of the synth is generating. 
>>Compared with the ground of other synths or the wall outlet ground the 
>>difference is also 15V! This means that connecting a synth to the external 
>>input i made on my synth makes that current is flowing between them. I 
>>don't like that... and I get lots of weird behavior when i make the 
>>connection.
>
>I'd unconnect everything from the synth, and check the GND of your external 
>connections jack against the GND point at the PSU. Could be that there is 
>some accidental connection between either supply rails and your case/jack 
>GND.
>
>>I have a symetrical power supply in the synth that gives +15V and -15V. 
>>I'm using a power distribution board identical to the Oakley Sound Dizzy 
>>board. All panel grounds, board grounds and digital grounds come together 
>>on the distribution board and are connected to the power supply's 0V.
>>
>>I am using a 3-pin mains power connector connected to a grounded wall 
>>outlet, but internally i'm not using this third pin. Should I?
>
>If the transformer you're using is haveing double insulation then that 
>should be ok.
>
>Cheers,
>  René
>
>--
>uzs159 at uni-bonn.de
>http://www.uni-bonn.de/~uzs159
>
>