What do the numbers on computer power supply transformers mean? Where can I get datasheets for these types of transformers?
You might try these people in North Devon: -

However, what you'll probably find is that the number has really no generic information about the winding details and ferrite core and, by implication, very little design information can be inferred from it but, good luck, Visualux may be the manufacturer if you are lucky.
The &quot;19B&quot; part does imply some reasonable information about the size and that, in turn, can tell you a lot about the ferrite core size but not the ferrite material. And, unfortunately there are no clues as to the number of copper turns or how many windings but, my advice is speak with them.