Printed Circuit Motors for High-Speed Incrementing of Inertial and Dissipative Loads

As a high-speed incrementer, the printed circuit motor, while less accurate than a detented incrementer, provides unusual flexibility and reliability with relatively simple input controls. This paper presents an analysis of printed circuit motor response to a unit step of input voltage for incrementing purely inertial and dissipative loads. Incrementing is stable and quite accurate if sufficient friction damping is provided. Input power requirements can be accurately predicted in terms of motor and load parameters, increment displacement, and increment time. Average power during an increment varies approximately as J
²
, θ
²
, and (1/T)
⁴
. Armature heating dictates maximum input power and incrementing rate. With external cooling and 120 watts average input power, a combined load of 0.009 oz-in-sec
²
moment of inertia, 10.8 oz-in/100 rpm eddy current damping, and 20 oz-in friction damping was incremented at a continuous rate of 150 steps/sec for 5° increments with ±6 per cent accuracy.