Vibration Characteristics of the Printed-Circuit Motor

Since optimum damping is difficult to achieve, raising the natural frequency of the printed-circuit motor is necessary for smooth starting and stopping. Designing for this higher natural frequency also produces the minimum mechanical time constant and the optimum power dissipation. A motor with a higher natural frequency requires stiffer substrate material in the armature. The nature of the armature requires that the substrate material be a fiberglass composite, an inorganic composite or a sapphire composite. Experiments produced an armature assembly with a natural oscillation of several thousand cps outside the start/stop (exciting) bandwidth of the motor.