Re: 48V 10A! Mauch 2A board?

Hi Randy,
In your software, which way are you pulsing your
STEP movement. Neg to Pos or Pos to Neg?


Bob





--- In CAD_CAM_EDM_DRO@y..., Randy Gordon-Gilmore <zephyrus@r...>
wrote:

> I was cleaning up some in the garage/shop (what else do you do with

a day

> off work anyway? :-) and ran across a 48V 10A linear supply (an

Elpac

> BFS500-48) that I didn't know I had! It was in a piece of

equipment thrown

> away at work a while back, that I dumpster-dove.
>
> I've been having random intermittent dropouts (where an axis will

stall and

> whine instead of moving) on my Sherline (Mauch 2A board, 24V 8A

switching

> supply) and remember reading that switching supplies will sometimes

not

> have a tolerance for the spiky voltages produced by a chopper

driver. I do

> have a 4700ufd 50V cap across the output terminals of the supply.
>
> So far, my response has been to set G0 moves at 20ipm from 30ipm

and lower

> the acceleration to where it audibly ramps. But then, on finish

profiling

> moves at 12ipm an axis (usually X) will still sometimes stall. It's
> frustrating, since 99% of the time 30ipm rapid and 12ipm profiling

are

> fine.
>
> I'm tempted to wire in the linear supply, but Dan has only

mentioned trying

> the board at 38V. I do have a little switching regulator feeding

the 5V

> logic input, and have a regulated 5V linear supply that I could

also use

> there. Make that would also use, since I just saw that the 78SR105V
> regulator has a 30V maximum input.
>
> Has anyone used a 2A board on 48V? The L298 datasheet says 46V

working

> voltage, with 50V absolute maximum. Would I be pushing things too

far with

> 48V? Dan, what would be the next component I should beef up? :-)

The

> L298's are on a big finned extruded heatsink with a fan blowing

down its

> length.
>
> Best regards,
>
> Randy
>
> Randy Gordon-Gilmore ,----.___________ ______________

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