Re: variable V power supply

Peter,

One reason for the "unregulated" supply is they usually
are more of a "big transformer with a large output filter
capacitor". The large output capacitor helps reduce the
ripple of the power supply.

With the "cheaper" linear power supplies they are lower
cost, but in part as they don't use a large output
capcitor.

Two linear power supply examples examples:
http://www.mpja.com/product.asp?product=6646+PS
http://www.mpja.com/product.asp?product=8527+PS
(These are 48V @ 8Amp-or-10Amp supplies)

Either would work fine, but the unregulated supply
is cheaper. Notice the size of the transformer
and capacitor of the "unregulated" supply.

Since the gecko is switching large inductive loads,
the ripple current will be higher than expected with
a linear supply. Linear supplies use more electronics,
and do not require the large transformers or capacitors
like the linear supply (hence they are less expensive).

A linear supply like:
http://www.mpja.com/product.asp?product=12425+PS
(Note this is a 48V, but only 3.3Amp)


Hope this helps.

Tom Walter

P.S. For the EE's (electrical engineers) on the list,
yes there are transformers and capacitors in the
switching power supply... but they are running at
10 to 50KHz (or 125KHz) allowing for much smaller
sizes. Not an issue with an resistive load, but add
in a large inductive load... and watch the ripple
go wacko! ;-)

--- In CAD_CAM_EDM_DRO@y..., cadcamcenter@y... wrote:
> Hi,
>
> The recommended power supply for gecko, camtronics, etc motor
drives
> are unregulated power supply. Is there anything against the use of
> regulated power supply other than cost considerations?
>
> Is it advisable to use variable voltage power supply to power these
> motor drives? Has anyone ever used variable voltage power supply to
> power these drives? Anyone has any plan/diagram/source for a
variable
> voltage power supply that can drive these with sufficient capacity
> for any motors likely to be used for a Sherline or equivalent
system.?
>
> Thanks
>
> Peter