Here is my light in the room. It use 24 V AC 50 Hz. I use for it a 230/24 V transformer, S=400 VA, here is P=S because cosf=1

4 pieces CD 408 Insulators and 4 pieces DG.3 Hungarian porcelains hold the copper wires. Two lamps are in serial, and 5 pair lamps are in parallel. The lamps need 12 V, they are 35 W. It is good, because id don't need big current.