Since you live in Brazil, have you thought about building your own generator? It is absurdly easy.
You can make quality ionic silver using Esstee's very simple design. Esstee is our on site Expert Guru.
3 - 9 volt batteries or an old 24 volt power supply
1 - current limiting diode, 5 milliamps
2 - #12 guage Silver Wires
some wire & alligator clips.