So I've designed this simple circuit for an electric vehicle. The inductor and resistor that are boxed off are the motor. The way it works, as you can probably figure out from the diagram, is that the RC circuit on the left controls how long the right side of the circuit runs (via the transistor). The resistor in the RC circuit is a potentiometer, and the time that the whole circuit runs is easy: t = -R*C*ln(actV/V) where actV is the minimum base-emitter voltage drop on the transistor. My question is about the second half of the circuit. Is there an easy way to predict how far the vehicle will travel if the only thing powering it is that motor? Does the transistor act as an amplifier as well as a switch? My attempt to predict the outcome was to say that the power applied to moving the vehicle was proportional to that dissipated in the motor. I treated the motor as a resistor and found the Power = V^2/R = F*v. Is this realistic? Here is the diagram: The goal of this is to have an electric vehicle that will run on its own for a distance dependent only on the two variable resistors.