A method of radio transmitting packets and transmitter. The pulse-width modulation unit converts a driving input signal into a positive-negative narrow pulse-width signal. The substrate has a first side, a second side, a sidewall between the first and second sides, a first indentation at the sidewall around a periphery of the first side, and a second indentation at the sidewall around a periphery of the second side. The flow rate is based on a first estimated volume of the fluid necessary for the first gear engagement element to produce the first torque.