change the speed means changing the speed at which the hammer strikes the bell.. ( jeeze cant you work that out????) ive told you what the current is MANY MANY TIMES the max it will be pulling is 4A but i want it to be able to withstand 6A just to be sure... anyway in the mean time ive worked it out and realised from this forum that no-one has a clue what they are talking about at all and everyone totally forgot that the bell would be producing an AC current of its own... so call experts.. more like the blind leading the blind... cya