If you know what you need in a power supply, old stereo amps are lying around unused these days since everybody is switching to 5.5 channel home theater or better. Each half of a split supply for a 30 watt per channel 8 OHM amp is usually around 30-35 volts, safe for most stepper ICs that supply 1.5 to 3 amps. The SureStep 34066 434 oz-in stepper motor uses about 14 watts. A 30 watt per channel class B amp is less than 50% efficient. 60 watts x 2 = 120 watts. If we assume the power supply is not meant to handle full power continuously, and drop back to 1/3 of that we get 40 watts. 3 axes using this stepper motor would consume 42 watts. So a 30 watt per channel amplifier would probably have enough stuff to power 3 good sized stepper motors. The only problem I would see is rewiring the supply to have both halves occur above the ground reference. If your stepper controller can handle 40-43 volts, a 50+ watt per channel amplifier would probably handle all 3 motors on just the positive half of the supply. These are just rough estimates. If you have access to an old audio amp, measure the power supply voltages first, preferably with and without a load, to make sure it wouldn't fry your stepper controller.
> > > > phase. I am driving them at the 75% current setting on the board, > > supplying the board with 28VDC from a nice switching power supply > rated at > > 7.5A. > > On the face of it, that is good. In practice, maybe not. The > problem is > that these supplies definitely do not well tolerate a motor load that > effectively uses the power supply as storage for unused motor > winding energy > when the current switcher in the driver turns the motors off at > the set > current. If the supply can tolerate a 4700 or more microfarad > capacitor on > its output, that would help, but many supplies cannot tolerate it > and will > shut down if good designs, or just go crazy for poorer designs. > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
