Okay, allow me to try again. An npn has a collector, base and emitter. A servo has a signal, +5v and gnd. I want to use pin 4 on my arduino to drive the servo. With no load i can attach pin 4 to the signal, the arduino's +5v to the servos +5v and have them share a common ground. But since the servo will have a load, and i dont want to draw all of the current from the arduino itself, can i use that same singal wire, pin 4, running in parallel to the base of the npn and the servo while the collector is connected straight to the battery and the emitter connected straight to the +5v of the servo.
So common ground, collector connected to battery, emitter connected to servo +5v, and pin 4 connected to both the base and the signal of the servo. Will that work?