I saw your reply…but missed you mentioned it was for an enlarger 
Durst made pretty high end enlargers. I went through a lot of enlargers over the years in the various darkrooms I built, worked in, maintained and my personal Durst M305 and then replaced with an M605 were some of my favorites. (though the additive color head Beseler we had in one lab was a lot of fun - instead of constant illumination it used pulses - and instead of CMY filters it used RGB so it was like a disco of all R/G/B lights going off when you’d do an exposure on that thing, we only used it for cibachrome which we didn’t do very often so it was a special treat to fire that thing up.)
None of the other enlargers I owned or maintained B&W or Color came with a stabilized power supply like the Durst. I assume they did it just to get more consistent exposures. Probably didn’t make a big difference unless you lived somewhere with really unstable power though. Most darkrooms I worked in had cheap inaccurate enough timers that you probably had more time variation leading to inconsistent print results.