You should be able to substitute bigger output transistors and emitter/source resistors for the originals. You might have to go to a lower resistance for the resistors to "trick" the drive into not going into protection. Halving their resistance would allow 5 Amps from a circuit designed to limit at 2.5 Amps, etc.
If the drive uses TTL chips, there should be plenty of base drive for the heavier outputs. If CMOS, you might have to use Darlingtons for the outputs. Your stock drive probably uses plastic TO-220 outputs, right? Some 2N3055s (with proper heatsinking) would allow around 15 Amps. Resistance divided by 6, use 2 Watt non-wirewounds in parallel to get the power rating. Big honkin' NEMA 56 motors would be easy for it. hth, Emory On Sun, Dec 7, 2008 at 10:55, Len Shelton <[EMAIL PROTECTED]> wrote: > If you read that whole post, you'll share everyone's disappointment. > Apparently there is a bug in that chip that causes incorrect microstep > angles and Allegro is unwilling to admit it or correct it. > >>Len > > > > -----Original Message----- > From: BRIAN GLACKIN [mailto:[EMAIL PROTECTED] > Sent: Sunday, December 07, 2008 10:48 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] microstepping stepper power drive > > Perhaps this discussion will offer something to you. > > *New Allegro Bipolar Stepper Driver A3986* > http://cnczone.com/forums/showthread.php?t=24699 > > Opening post suggests 10A at 50V. Have not had the time to read the entire > set of posts. > > On Sun, Dec 7, 2008 at 10:23 AM, Ian W. Wright > <[EMAIL PROTECTED]>wrote: > >> >>How many wires do your motors have? >> > >Len >> >> One has 8, the other 6 so it doesn't really mater whether >> the drive is unipolar or bipolar. >> >> -- >> Best wishes, >> >> Ian >> ____________ >> Ian W. Wright >> Sheffield UK >> >> "The difference between theory and practice is much smaller >> in theory than in practice..." >> >> >> > ---------------------------------------------------------------------------- > -- >> SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, > Nevada. >> The future of the web can't happen without you. Join us at MIX09 to help >> pave the way to the Next Web now. Learn more and register at >> >> > http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > ---------------------------------------------------------------------------- > -- > SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. > The future of the web can't happen without you. Join us at MIX09 to help > pave the way to the Next Web now. Learn more and register at > http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. > The future of the web can't happen without you. Join us at MIX09 to help > pave the way to the Next Web now. Learn more and register at > http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- "Those that forget the pasta are doomed to reheat it." Emory ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
