Look up Current Regulator & Limiter Diodes IN5299 Min 1.080 - max 1.320 MILL
Amps (any large electronics seller example Mouser),
IN 5283 thru IN5314 with one of these soldered to any DC power source
Regardless of Voltage You can make a constant current generator
Even with a lower voltage you can move Silver closer together and stay at
rating on Current limiter.
Current limiter will lower voltage automatically to stay at its rating.
There is a whole range of these Current Limiters which one you use depends
on how much service area of silver you have.
The 1 mill amp works great on Canadian Maple Leaf coins.
Bob