Low Vibration Linear Motor Systems

A portable fuel cell system comprising:

• a fuel cell having a fluid path including an intake and an exhaust;
• a pump having a pumping chamber disposed in the fluid path and a mechanical input;
• an electric motor, having a power signal input, the power signal input being removably connectable to an electrical power source, and having an oscillatory mechanical output coupled to the mechanical input of the pump, the mechanical output having unwanted vibration primarily at a first drive frequency of a power signal at the power signal input;
• a spring and mass assembly configured to have a resonance at the drive frequency and coupled to the mechanical output of the motor so as to vibrate out of phase with the mechanical output of the motor at the drive frequency and so as to reduce the unwanted vibration of the mechanical output at the drive frequency;
• a vibration transducer, physically coupled to the mechanical output of the motor, and having a vibration transducer signal output;
• and,
• an electrical control system having an input coupled to receive the vibration transducer signal output and having a control output coupled to the power signal input of the motor;
• wherein the control system is configured so that the control output causes a reduction in vibration of the mechanical output of the motor at least one harmonic of the drive frequency.