Re: Power Supplies

Greetings.....

About switching power supplies.....Anne's experience may
have been avoided if a load was placed on the +5v output.
A word of caution when using " switchers " that have multiple
output voltages! Typically , the regulation of the supply
is provided via feedback from the " lowest " output voltage.
Plus...the peak primary current , in current-mode control.
Not all topologies of switchers are satisfied to operate in
an unloaded condition. Skipping past the thesis , you can use
a couple of approaches : First-beware of " vintage " switchers,
Second-check datasheet or with the manufacturer to verify that your
switcher can indeed operate " unloaded ". Third-apply a minimum
load to the lowest voltage output ( especially if unused ). A
minimum load is usually 10% of the rated output current. If all
else still looks dim , save yourself and pick-up a surplus switcher
at Jameco <www.jameco.com> ....they are kind enough to label their
switching goodies with the loading requirements. Learn more about
switchers at < www.smpstech.com >

Regards......
Steve

--- In CAD_CAM_EDM_DRO@egroups.com, Anne Ogborn <anniepoo@n...> wrote:
> Jon Elson wrote:
> >
> > William Scalione wrote:
> >
> > > If anyone is interested in some 24V @ 62A switching power
supplies for
> > >
> > > drives
> > > I have some $25.00 each new in the box. Astec VS3 models They
also
> > > have
> > > a
> > > 5V @ 60A output which should be enough to power your TTL (or
weld
> > > with it).
> >
> > Wow, that's almost 1800 W DC. What is the input? 240 V? 3
phase?
> >
> > Jon
> >
>
>
> I have a power supply, sounds like this. Mine's marked +- 12@8A &
> +5@75A, but looking inside it we can't believe it'll supply that.
> We hooked the +12 up to a 3A draw, it worked for an hour, then
> failed.