On Friday 26 September 2014 10:24:09 John Alexander Stewart did opine And Gene did reply: > Andy, Gene - I do have a spare 12v linear regulated supply and a nice > small 5v switching sitting by my new mill, was going to prototype with > the 5v first. (KBIC says 0-7v input in voltage follower mode - 0-5v > will get me going) > > Interesting about the dc-dc converters; on reading, as Gene says, some > are isolated, some are not. > > The local store does have lots of switching power supplies of varying > voltages, and I do have a large metal box for all of this to go into, > but I dislike clutter.
That is why you put the clutter in a swarf proof box. ;-) And while I am at it, some of our servo controllers will, when slowing to stop or reverse, dump the motors energy back into the the psu, raising its output voltage significantly. Very few switchers are capable of dealing with that and will go into over voltage protection shutdowns. So anytime I'm not pure steppers, I use a simple transformer and cap supply, it doesn't "bither them a bot". :) The fact that it needs a 2 wheel hand cart to move it any great distance is beside the point. What I finally wound up with here, to run a 1 HP rated escapee from a treadmill, has a 2500va transformer and a need for a strong back to move it. Parts cabbaged from an old Phase Linear dual 750 rms watts a channel amplifier, and caps from an IBM printer that was about the same size as a 17 cu ft chest freezer when it was alive. The Phase Linears caps were only surge rated to about 125 volts. But I have 150 volts for a surge margin using 2 of the IBM caps with a 5k equalizer bleeder across each, wired in series. I think I can weld stuff with it. Evidence of that is a nice steel cookie socket in the side of a wrench that shorted them a day after it had been turned off before I added a 7 watt xmas tree lamp to the output for a bleedoff. Takes several minutes at that, big caps, 3" in diameter & 7.5" tall. 19,000 uf IIRC. > So, I'll see if the local store has a 12v 12v dc isolated converter > that is small and compact. > > I appreciate the isolation warnings; while I do realize that I'm > playing with 110v, 15A here, but it is nice to have the reminder, and > also, for others who may stumble across this thread. > > Thank you! JohnS NP John Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Meet PCI DSS 3.0 Compliance Requirements with EventLog Analyzer Achieve PCI DSS 3.0 Compliant Status with Out-of-the-box PCI DSS Reports Are you Audit-Ready for PCI DSS 3.0 Compliance? Download White paper Comply to PCI DSS 3.0 Requirement 10 and 11.5 with EventLog Analyzer http://pubads.g.doubleclick.net/gampad/clk?id=154622311&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
