[sdiy] OT: 48v psu for dc motor

[Roy J. Tellason]

On Wednesday 21 November 2007 15:14, Seb Francis wrote:
> Hi Julian,
>
> I don't have any specific experience in this area, but I would say that
> this is quite a lot of current and you really need an efficient PSU.  So
> switch-mode rather than linear (and definitely easy to buy off the shelf
> rather than design your own).

I do quite a bit of reading on lists that are oriented toward mechanical and 
CNC pursuits,  and the consensus of opinion seems to be the opposite of this.  
The reason for it would appear to be back EMF -- when a motor is decelerating 
it tends to dump power back into the supply.  The filter caps on a simple 
linear supply deal with this just fine,  if they have appropriate voltage 
ratings,  while switchers don't often like it that much.

(Snip)
> It's not like you need ultra-clean DC to drive a motor.

No,   you don't.


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