UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Getting a VA Rating from a Transformer’s Mass

turretslug · 30th Jan 2021, 6:35 pm

Interesting point Bazz, and I'm certain that I'm not the only one here who's often looked at a second-hand/anonymous NOS mains transformer and thought, now what can I reasonably get from this? I suppose that there will be outliers in expensive specialist types with exotic magnetics and particularly cheap'n'nasty ones that run hot but low duty-cycle for ephemeral consumer electronics but most run-of-the-mill types presumably run in a middle ground. After all, ISTR even that copper and steel have similar densities (copper typically 10% higher), so even an individual design bias toward one or the other won't throw things too far off track.

As Mr. Scott would say, ye cannae change the laws of physics....

Colin

30th Jan 2021, 6:35 pm	#2
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,400	Re: Getting a VA Rating from a Transformer’s Mass Interesting point Bazz, and I'm certain that I'm not the only one here who's often looked at a second-hand/anonymous NOS mains transformer and thought, now what can I reasonably get from this? I suppose that there will be outliers in expensive specialist types with exotic magnetics and particularly cheap'n'nasty ones that run hot but low duty-cycle for ephemeral consumer electronics but most run-of-the-mill types presumably run in a middle ground. After all, ISTR even that copper and steel have similar densities (copper typically 10% higher), so even an individual design bias toward one or the other won't throw things too far off track. As Mr. Scott would say, ye cannae change the laws of physics.... Colin