i iknow tDCS about 4years and test it about 3 , but eraly test it vas only 9volt batery , potentiomether(I must regulate current manualy) and 2 electrode from w

i iknow tDCS about 4years and test it about 3 , but eraly test it vas only 9volt batery , potentiomether(I must regulate current manualy) and 2 electrode from watch cover