2009/10/10 Jon Elson <el...@pico-systems.com>: > witch. > Warning! The spindle speed controller on these machines is NOT isolated > from the > line. So, you need to provide some sort of isolation for and speed > controller interface > to the computer. PWM and optocouplers sounds like a good idea.
When he says "Not isolated" he means 100V above ground, at least in the case of mine. Mine is a KBIC240D, the manual is here: http://www.kbelectronics.com/manuals/kbic_manual.pdf and it says that for external voltage control you need to supply a control voltage between P2 (normally the pot wiper) and F- (which is one of the motor terminals!) Fortunately there are small DC-DC converters that will produce a completely isolated 12V (or whatever) so it isn't as much of a problem as it sounds, just be careful with that control signal inside your control box and keep it away from other stuff. You probably need a PWM-voltage converter, preferably opto-isolated. I built a circuit which uses a precision current-source to charge a capacitor to control my drives and to operate FW/REV relays. http://imagebin.ca/view/FVZ50EL.html You would only need half of that, as I am controlling two spindles and choosing between them with binary logic. (You can quite probably improve on the circuit too) There is an article on closed-loop spindle speed control in the Wiki. http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Closed_Loop_Spindle_Speed_Control -- atp ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
