RE: Re: OT PSU's

["Ward, David" <DAvid.Ward@xxxxxxxxxx>]

sorry, patrick, actually you could,

regulated just means that the voltage or current is controlled and
maintanied within the supply specification.

There are two types of regulation you commonly see specified with PSUs :
Load regulation - The output voltage variation due to a load change at
constant input voltage.
Line regulation - The output voltage variation due to input voltage change
with constant load.

however I agree that in the case of 99.99% of domestic PSUs AC supplys
won't
be regulated ;-)


Dave


-----Original Message-----
From: Patrick Lidstone [mailto:patrick@xxxxxxx]
Sent: 28 June 2004 16:13
To: ukha_d@xxxxxxx
Subject: [ukha_d] Re: OT PSU's


--- In ukha_d@xxxxxxx, Jim Noble <yahoo-groups@b...> wrote:
> Patrick Lidstone wrote:
>
> > --- In ukha_d@xxxxxxx, groups@w... wrote:
> > > I am after a PSU that is rated 18 Vac 300mA but despite
weeks of
> > searching the
> > > nearest I can find is one from CPC that is 18 Vac 500mA
unregulated.
> > >
> > > My question is is this safe to use?
> >
> > Yes, without any doubt whatsoever.
>
>
> I'm not so sure about that. Unregulated power supplies put out higher
> voltages when not used at the design load.
>
> If the no-load voltage of the psu is less than the terminal voltage
(ie
> one that will kill it!) of what you want to connect, then you're
> probably ok. Otherwise; your call ;-)
>
> (It'll probably only be a few volts higher at 300mA though).
>
> You'd definitely be safe with a >300mA regulated psu...
>

You can't have a regulated AC supply. It's a contradiction in terms.

Patrick