Anyway, he has just stumbled upon this device in his back garage and thought he gives it to me, knowing I'm making myself familiar with electricity and Arduinos nowadays. (Basically I'm an IT guy). I think I'll use it for my PC's Genius 2.1 hobby hifi first, I always hear a pop when somebody opens the warm water tap (the circulating boiler starts to heat) and then again one when it stops. It's a rental flat (yet, but moving soon into own house) so we can't completely redesign the in-house electricity here, although pretty new (10yrs).
Anyway, just thought I'm bringing it into this thread for fun and to laugh but if it turns out it's even useful, woo-hoo. It's really looking and smelling oldschool, built like a tank. Otherwise not big, about 10cm on the long side.
Edit: called him right now, it's from an old Russian industrial computer.