I am planing on controling water pump with my raspberry pi, and I didn't want to have 2 or more batteries so my thought was i could from 3.3v raspberry pi gpio output get 12v. with boos conventer to power the pump . I think Omh's law goes something like this : what you give you will get , so with P=U*I will "U" go up form 3,3 to 12v but "I" will drop and "P" will stay the same. So my question is does it work like that and if it does can my 12v pump start because of small currency. Sorry for bad english.