Hey so I have a remote control helicopter that outputs 4v to the motor when I give it full throttle on the remote and goes down to 0 when i let it go. I want to know how to increase the voltage to 9v when i get on the throttle...is it possible to use a transistor? or a relay? Thanks in advance ![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)