On Monday 07 December 2015 06:52:38 andy pugh wrote: > On 7 December 2015 at 11:23, Gene Heskett <[email protected]> wrote: > > a third (mechanical) relay that connects a crowbar > > > >> resistor across the caps when the power goes off. > > > > That was the reason for the night light lamp cobbled into mine, but > > its since burned out, probably from some rigid tapping as Jon's WM > > servo is a full 4 quadrant amplifier, lighting up that lamp well > > past its normal brightness as it reverses the spindle motor. > > If you are using the Pico servo amp then I guess you are running from > 120V power? > Yes, with a slight stepdown, so the rectified voltage is about 126 no load, 123 when the motor is at 2500 revs but not loaded. And they can do serious damage to a screwdriver an hour after powerdown, so I definitely need to restore some means of bleeding them off when powered down. IIRC I saw some mini-candelabra sockets at Wallies a while back so I need to get 2 of them and put a lamp across each half of the supply. Its 2 in series and 2 of those in parallel. You can see the jumpers between the buss bars in the pix.
> My caps are charged to about 320V which makes me rather wary of them, > hence the active discharging circuit. Yes, thats not play voltage for sure. Neither is mine, but I've been used for the discharge medium for higher voltages than that, several times. Somehow, I'm still here. Not my time I guess. A good jolt and some burns can sure put you up for a month with shingles though. That is definitely NOT on my list of fun experiences. 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) Some mill pix are at: Genes Web page <http://geneslinuxbox.net:6309/gene/GO704-pix> ------------------------------------------------------------------------------ Go from Idea to Many App Stores Faster with Intel(R) XDK Give your users amazing mobile app experiences with Intel(R) XDK. Use one codebase in this all-in-one HTML5 development environment. Design, debug & build mobile apps & 2D/3D high-impact games for multiple OSs. http://pubads.g.doubleclick.net/gampad/clk?id=254741911&iu=/4140 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
