----- Original Message ----- From: "Andy Pugh" <a...@andypugh.fsnet.co.uk> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Sunday, April 25, 2010 1:50 PM Subject: Re: [Emc-users] Resolver to Quadrature Convertor
> On 25 April 2010 18:28, RogerN <re...@wildblue.net> wrote: > >> In your opinion, do you think the Arduino would work to use as an >> amplifier >> by using 1 resolver and adding 3 phases of PWM to drive 3 half H-Bridges? > > Possibly, and it is something I have been thinking of looking in to. I > am not sure if it is possible to persuade the Arduino PWM drivers to > do the complementary low-side driver signals that I think are needed. > It might be easier to write a 3-phase PWM comp module for EMC2 to > create the driver signals. There is already one in the Hostmot2 > software, but it is not currently supported in the EMC2 has drivers. > (That might change) > > What is possible (and I have a version of the Resolver code that > already does it) is to synthesise Hall sensor signals to pass to a > generic BLDC motor driver. However most BLDC drivers don't handle the > voltages that servos are designed to run at. > I have made my servos rotate with a generic BLDC driver, but only > slowly (lack of voltage / high rotor inductance I think) and only > briefly (something odd about the drives, they trip out on overload > even with small BLDC motors well within their stated parameters) > > I am thinking of buying one of these for further experimentation: > http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6880732 > Mainly as the package includes shoot-through protection and I don't > trust my coding skills. > > -- > atp > > ------------------------------------------------------------------------------ I see brushless servo amps on ebay for reasonable but I think most require hall signals. http://cgi.ebay.com/AMC-brushless-servo-amplifier-BE25A20E-/310165227459?cmd=ViewItem&pt=BI_Control_Systems_PLCs&hash=item483749c7c3 I believe the above is 25A (peak, 12.5A continuous) at 200 (maybe 240) Volt, should be good for about 3HP of servo. Also I have seen some amps from Pacific Scientific that work with encoders or resolvers and will give a quadrature encoder out to the controller, I guess that would be a nice all in one solution. RogerN ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
