Re: My power supply calculations and a zener question

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> Interesting, There was a post some months ago that you figure

total

> motor watts and size the power supply for 2/3 to 80% of that.

since

> your total is much less when you size on watts, you may be

surprised

> just how small the power supply need be.
>
> regarding caps, oversizing is not a problem and getting voltage
> rating 20% (or more) higher is allways a plus. use 50V for the

35V

> power supply.
>
> I seem to remember using a diode across the motor to limit voltage

as

> a no-no.
>
> Dave

Well, I wasn't sizing this on the motor amp ratings. For the moment
I'll just be running dinky P5111's (5V/1A) on my particle board and
1/4-20 screw throw-away practice mill. Don't really want to size the
supply on those :D I need to buy bigger later but how big I don't
know yet. I'm assuming I can probably get away with Nema 23s, maybe
the 60ish in/oz, maybe the 100ish... Just don't know at this point.
But tossing around an 18x18 PCB can't require all that much...

I figure make the power supply able to handle the biggest things
this driver can handle then I won't have to make another one later
for the larger motors.

I think the zener is supposed to go by the cap to limit the whole
system, not across motor leads.