On Fri, 26 Jul 2013, andy pugh wrote: > Date: Fri, 26 Jul 2013 14:44:28 +0100 > From: andy pugh <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] Two phase BLDC motors > > On 26 July 2013 13:09, Andrew <[email protected]> wrote: > >> I need to drive rare 2-phase BLDC motors, 60V 22A. Is there a suitable MESA >> hardware for LinuxCNC? > > What does the excitation pattern look like? > >> Though I guess bldc comp is meant for 3-phase motors. > > It is, but as it is a ".comp" it is easy to modify. > > The 3-phase excitation pattern is encoded in a 2-digit octal constant. > The binary bits correspond to Ah Bh Ch Al Bl Cl > http://git.linuxcnc.org/gitweb?p=linuxcnc.git;a=blob;f=src/hal/components/bldc.comp;h=20c882ed95966d2b727e8b402b1e639907d22b85;hb=94d3babf892e2680714696df05ead32cace79c83 > Line 402 is a comment showing the hall pattern. > The next 47 lines cover every possible mapping from a hall pattern to > a phase pattern. You would only need to consider one pattern. > > 024 means: > 0 = Octal Constant > 2 = 010 binary, ie Phase B high > 4 = 100 binary, ie Phase A low. > > I don't think that this scheme will work for a 2-phase motor as I > suspect it has 4 wires, so there aren't enough bits in octal. > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto >
2 phase motors normally have sine/cosine drive (like a step motor) so if BLDC had a phase offset parameter (default 120 degrees, settable to 90) 2 phase motors could be accomodated. (ignoring HALL patterns if such things exist for 2 phase PMSMs) Is 22A peak or continuous? If continuous it may have a 70A or more peak current rating! Peter Wallace Mesa Electronics ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
