On Saturday 15 March 2014 14:33:33 Gene Heskett did opine: > On Saturday 15 March 2014 06:42:37 Steve Blackmore did opine: > > On Fri, 14 Mar 2014 16:23:33 -0400, you wrote: > > >Greetings again; > > > > > >After putting in a diode, that part seemed to work, but this C41 > > >seems to have gone south again. (and again (and again)), and its > > >looking like a 4th one has failed. Symptoms seem to be an output > > >impedance in the 100k region, making 375 rpm maximum, and dropping > > >nearly 100 rpm when I put a 10 megohm digital meter on its output to > > >measure it, and getting a hair over 5 volts for my trouble, and a > > >fresh LM358 in the output voltage follower stage acts exactly like > > >the one I pulled out thinking it was bad. > > > > Very odd - have you spoken to Arturo or emailed him? > > > > Steve Blackmore > > Not recently Steve. He has the attitude that if I modify it, I'm on my > own. Said in one of his responses that it was made to run with a pwmgen > max frequency of 5hz! 2 or 3 requests for a schematic have been ignored > in any replies I have received from Arturo. > > The mods I've made serve to speed up the response considerably as its so > slow out of the bag that a PID controller in front of it just sits there > and goes rail to rail at about 2 hz at Pgains above 5. With the mods, > its stable at Pgain=40 giving fairly stiff control above 300 rpm. > > Because he is so unresponsive, I have not attempted to email him about > this. > > I figure if he cared, he would be monitoring the list, but apparently > LinuxCNC does not represent enough of his market to be worth it. His > loss IMO. I've been effectively been thrown under the bus, so I no > longer care. If I can find something else, so much the better. > > In the meantime I'll continue to troubleshoot it, but it would be many > times easier to do IF I had a schematic. > > Cheers, Gene
Ps, went to his site, found docs on a new version of it with 2 features, 1st being an input terminal for the high end of the pot its replacing, something this one does not have, labeled 12 to 24 volts and the note that its now designed for a 100hz pwm signal. But when you goto the order pages, its not listed, so you still can't buy it. And according to the curves, its 1% linear now IF you ignore its minimum output voltage of around 200 millivolts, not low enough to reset the Gemini controller reliably. Not noted is if that means the 5 volt 300ma input is now ground common to the logic ground. It is not on V1.1 boards, thats all hot to the powerline from the controller. So I have quite a bit of exposed hardware in my box thats hotter than that famous little red wagon. Of, and the price has gone up a few bucks. TBE, but sure wish my SS COLA matched it. :( Cheers, Gene -- "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> ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
