Change common bell for electric doorman
When I was 10 years old, the bells were coming with a bell of 12 volts (at least in the federal capital today CABA) I currently have 70 lollipops with some years in electric porters exclusively (more than twenty) and the only 220v bells I saw were in schools and fire barracks, in both cases placed with relay.
Beyond my "town", at the beginning of the nineties I worked in electrical service in San Nicolas de los Arroyos (BsAs), and the truth is that it was worse than where I worked before; but the point is not that they have not come from 12 volts, it is how it was connected, since they coexisted with the Russian bell and others of that type.
It may not be exactly a decade, maybe a little more, but the highest percentage of the timbres placed long ago were connected directly, and what is on the street today is still the majority.
