View Full Version : Power Supply Question?

04-06-2009, 04:26 PM
I'm thinking of cncing my little 9x20 lathe and have been doing a little studying lately to see if it is even feasible for me to do. I program and run machines for a living but I've never built one.

My question: Does it matter if I get a linear or switching supply as long as it is rated for what I am going to run? Or is one better than the other? What is the difference? I don't need a complete rundown on how they work, just some basics about them. Thanks for any info.

John Stevenson
04-06-2009, 04:48 PM
Just a plain transformer, capacitor and bridge rectifier.
the problem with linear supplies is that as an axis shuts off the back EMF has to go somewhere and the big cap help absorb it.

Remember the transformer will put 1.414 times the voltage out when smoothed and rectified so a 24 v AC transformer will spit out 34 v DC so watch the max voltage needed for the drivers and derate from that.
If a driver is 36 volts max, aim for about 28 volts