On 11/26/2012 03:13 PM, Ralph Stirling wrote: > Get a real power supply with a transformer, rectifier, > and capacitor. If you have switching stepper drivers that have *a capacitor across the DC input*, you may be able to use the power supply from an old 20 to 50 watt per channel stereo amplifier. With everything going to 5.1 or 7.1 for video, there are lots of older class AB stereo amps languishing in closets. A typical 30 Watts Per Channel amplifier will have a bipolar supply of around 30-35 volts. Taken from +rail to -rail gets you 60-70 volts.
My example steppers are from Home Shop CNC. Their 567 oz-in steppers draw 5A at 2.5V per phase. That's 12.5 watts per phase, or 25 watts per motor. that would be 75 watts average for a typical 3 axis router. A 30 Watts Per Channel amplifier should have a power supply capable of 60 watts average output, since class AB amps are relatively inefficient, so while it's outputting 30 watts RMS on two channels (60 watts output) the power supply should be providing more like 120 watts. That should be able to handle the 75 watts with a little ineficiency, but if you found a 50 Watts Per Channel amplifier, the power supply should have plenty of reserve. The best part is, people would be willing to give it away for a good cause! ------------------------------------------------------------------------------ Keep yourself connected to Go Parallel: INSIGHTS What's next for parallel hardware, programming and related areas? Interviews and blogs by thought leaders keep you ahead of the curve. http://goparallel.sourceforge.net _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
