RE: Linear Power Supplies for Servos


I am looking for a particular item for a machine. I need a linear power supply, i.e. not switching.

  • 75 VDC output but can be less and not lower than 48VDC; 225 Watts continuous power!
  • 53 joules of capacitive energy storage for lossless storage of regenerated energy and reduced output ripple
  • 13 watt excess regenerated energy absorption
  • Over-voltage and over-current detection and protection (designed to not false trip on the high peak loads of a motion system)
  • Soft-start, in-rush current limiting to prevent accidentally tripping circuit breakers upon machine power up
  • Reverse-polarity protection prevents damage to your motor drive if you accidentally reverse input power polarity
  • Short-circuit protection
  • Built-in EMI filtering
  • Automatic dump of bus power quickly brings output voltage to safe levels after power down
  • Wide AC input range: 95-125/190-250VAC; 50-60Hz

Those are high demands for a machine but I want to make sure I get it correct in this instance. Does your company sell linear power supplies that are not switching of this make?


P.S. is one co. I found on your site that seems a bit established in this field but I have seen a lot of their parts and power supplies are switching only.


Thank you for inquiring. To answer your first question regarding the supplier Mornsun, While we do carry the supplier, I do not see any linear products to offer.

Please click here to see what we do have

I have actually spent some time searching the various sections of our website for some options. I have found that I do not see anything available that meets all of your specifications.

Based upon your question I do wonder if a possible solution for you would be a supply for a UPS system. Something like this is still switching but is still designed to get the noise out with the higher voltage and current requirements. The following part is the only one I found that seemed to have much potential. Please feel free to take a look at it here:

Altech Corporation

I know this isn’t the response that you were looking for but I still hope that you find this useful.

@silver2row The listed criteria bear a striking similarity to those of Teknic’s IPC-3 product. I’ve nothing against Teknic (they make decent stuff that’s used in a few places around here) and I have no qualms about suggesting use of their supply products with their motor products as a minimum-effort solution; most commodity power supplies do indeed have potential for issues if used with loads that regenerate power.

That said, there’s no guarantee that any given servo motor application will necessarily involve sufficient regeneration to pose issues, and nothing particularly magic about “linear” power supplies from that standpoint; they’re basically a century-old design topology which happen to be less sensitive to the relevant issues of concern by virtue of being brutish and “dumb”.

This said, it’s quite possible to address these issues using a handful of discretes hung off the output of a suitable switching supply. A bit of design effort is involved, and may or may not be worth the hassle depending on one’s particular circumstances.


No issue. Although it is surprising at first, I have grown to want things that are not available any longer or ever. So, I will keep searching and looking through catalogs.


P.S. Thank you for spending time to reply to my wants.


Yes. It is the IPC-3 product that I was going to try to duplicate w/ a “second hand” supply. I have been not so lucky in my search.