I have a few of those, in a couple of boxes in my garage. Ray
--J. Ray Mitchell Jr. jrmitche...@gmail.com (818)324-7573 The things we admire in men, kindness and generosity, openness, honesty, understanding and feeling are the concomitants of failure in our system. And those traits we detest, sharpness, greed, acquisitiveness, meanness, egotism and self-interest are the traits of success. And while men admire the quality of the first they love the produce of the second. -John Steinbeck, novelist, Nobel laureate (1902-1968) On Fri, Oct 31, 2014 at 9:53 AM, Kirk Wallace <kwall...@wallacecompany.com> wrote: > In case anyone might be interested, I mentioned on IRC some issues I had > with a blown out unipolar drive: > > http://www.wallacecompany.com/machine_shop/Shizuoka/00001-1a.jpg > > > http://www.wallacecompany.com/machine_shop/Shizuoka/Bandit_Stepper_Driver.png > > http://www.wallacecompany.com/machine_shop/Shizuoka/Shiz_TIP36-1a.jpg > (Darlington = two xstrs on one mini pcb, TIP36C PNP pair on high side > for PWM current control on AA and BB, TIP35C NPN pair on low side for > motor coil stepping on A1, A2, B1, and B2) > > I got the last of the parts yesterday and installed them to the Y drive > and it works fine now. Unfortunately, the Z drive went out while > testing. This time I knew what to look for and had spares, so I repaired > the Z drive in short order. I hope there isn't another issue causing > these drives to go out. It seems that a transistor shorts out, taking > the other high or low side transistor out, then the fuse. On the other > hand, if there was an overload from the motor, I suspect just the fuse > would blow. (BTW, TIP35/6 = 25A, Fuse = 12A Fast Blow) > > In looking at how Darlington transistors work, I'm surprised that two of > the same transistors are used for the first and second stage (hFE = > 1600). I suppose transistors are cheap enough that there are no savings > in using a smaller transistor for the first stage. If another transistor > blows out, I may try a modern single module Darlington like these: > http://www.digikey.com/product-detail/en/2SD2083/2SD2083-ND/3661817 > http://www.digikey.com/product-detail/en/2SB1383/2SB1383-ND/3929429 > (hFE = 2000, one high side, one low side) > > Although, I really don't want to put much more effort into these old > drives. Plus the circuit traces are pulling up when I remove the old parts. > > -- > Kirk Wallace > http://www.wallacecompany.com/machine_shop/ > http://www.wallacecompany.com/E45/ > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
