It is an insulating transformer designed to supply circuit at a maximum of 50V (safety extralow voltage).
It is a transformer in which the primary and secondary windings are separated by a double or reinforced insulation, in order to limit, in the circuit supplied by the secondary winding, any risk due to accidental contacts with active parts or parts that can become active in case of an insulation fault.
The transformers are completely impregnated with a inorganic resin. This operation
improves the characteristics of the used materials, prevents the penetration of humidity
inside the core and the windings, reduces greatly the noises caused by the vibration.