48V 10A! Mauch 2A board?

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 ,----.___________ ______________ _________________
ProtoTrains // = = === == || == == == = || == == == = == =|
Rio Vista, CA, USA /-O==O------------o==o------------o==o-----------o==o-'
zephyrus@... http://www.rickadee.net/~zephyrus