Transformer identification

[Ingo Debus]

The Dark force of dance wrote:
> Yup that sound furry muff. That's basically how I do it. But then you get
> these weird telecom  transformers. Relatively huge heavy things rated at
> 300mA? Now we can assume that they're seriously over engineered but what
> seems to be the case is that they have huge cores and lots of wire, but
> it's all really thin windings.

Maybe these are transformers that don't need a low current fuse on the
primary side, they are safe enough with the 16A which is there anyway.
Here those transformers are often used for doorbells.

Ingo