[sdiy] negative DC power supplies ?

[Peter Blackett]

Dear Andreas,
I was thinking on the way home tonight,
how about using an Ac wall wart and then have a rectifier, smoothing and 
voltage regulators on the pcb itself ?
as long as the ac supply from the wall wart doesn't have an earth 
connection to the output voltage you should be ok
I know that ac wall warts aren't as easy to find as the dc ones.
regards Peter

> Thanks for the info!
> 
> However, if I use the +- supply during development then I will have 
> problems when I put it on PCB - I will need to create a neg current by 
> then! And I will (of course) connect an audio cable sooner or later, so 
> I can't use a positive ground to get minus DC either.
> 
> It's just strange that this is a problem... I looked for DC wall warts 
> and PCB mounted transformer components that can produce -10 : gnd : +10 
> volts and I had a really hard time!
> 
> So how do you people make a neg DC supply on a PCB?
> 
> regards
> -Andreas
> 
> 
> ---------------------------------------------------------
> 2005 jan 04  kl. 15.12 skrev Paul Perry:
> 
>> From: "Andreas Gaunitz" <andreas.gaunitz at konstfack.se>
>>
>>> I'm planning to buy a DC power supply, with limited current and digital
>>> readout etc, for my upcoming projects.
> !!!!!