Re: power supply

On 16 Oct, CAD_CAM_EDM_DRO@yahoogroups.com wrote:

> From: cadcamcenter@...
> Subject: power supply
>
> How dependable are transformer specs?

The voltages you list are interesting .. any chance you've got a 110V
transformer and are using it on 220 ? Dumb question, but first thing
to check.

Second thing .. was it a "cheap" transformer ? I have, over the years,
been quite astonished at what comes out of "wall warts". The DC
voltage at about 90% of the rated current is usually pretty close.
However, unloaded, they produce way higher voltage than spec'd. Maybe
not quite so high a percentage difference as what you're seeing, but
close.

It's my GUESS, knowing little about transformers but having seen LOTS,
that there are "qualities" of them, good and bad, probably determined by
the choice of materials and quality of manufacture. Properly wound
copper on high quality ferrite material with close attention paid to
air gaps just works better. As the winding "niceness" falls and as the
ferrite quality falls, so does the regulation and the efficiency.


Alan

--

Alan Rothenbush | The Spartans do not ask the number of the
Academic Computing Services | enemy, only where they are.
Simon Fraser University |
Burnaby, B.C., Canada | Agix of Sparta