Stuart Stevenson wrote: > Gentlemen, > The servo amps on my cinci are GETTYS Model N350/N135 33 amp. > These each have a few edge connected boards inserted on them for > different functions. > These are OLD analog boards. I am sure each component board could > use a good tuning. As this is not feasible (AFAIK), I am researching > how to remove the analog boards. I want to dumb down the amplifier and > use the tuning in EMC to control everything. > These have some heavy duty SCR's and heat sinks. Can anyone direct > me to documentation or a project I could use to modify these amps? > Stripping the board and using discrete components is an option. > Throwing them away and purchasing new amps is possible but I like > the idea of reusing some of the components. > Nothing is off the table. > Suggestions, comments welcome. > Of course, I am looking for cheaper - faster - better. :) Well, I don't know how well these will perform. The Fanuc A06B series of phase-control servo amps ran off 3-phase power, so they had 360 conduction pulses a second possible. If the Gettys amps run off single-phase, they have only 120 possible conduction pulses, which cuts severely into bandwidth. I'd expect they have a real bandwidth of 10 Hz or so. Fine for GE550 or A-B 7320 controls, but not much newer. You might run into some serious tuning compromises with such low bandwidth in the servo amp. Not much sense of EMC feeding 1000 new velocity settings a second to an amp with 1% that much bandwidth.
Without drawings of the amps, it could be a real headache to refit them for a different command scheme. Somewhere in there there is a one-shot circuit, probably using unijunction transistors, that controls the phase angle of SCR firing from the output of the current-loop error amp. That would most likely be a discrete op-amp, but maybe it is one of the first chip op-amps. Jon ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Register now and save $200. Hurry, offer ends at 11:59 p.m., Monday, April 7! Use priority code J8TLD2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
