5. It is necessary to select a DC servomotor such that its stall current is limited to 3.5 A, its starting
torque is at least 0.83 N.m, the maximum rotational speed is at least 425 rev/min, the maximum
power output is at least 9.5W, and the starting angular acceleration is at least 25 rev/s². The
parameters of an available DC servomotor are given as: nominal input voltage ($V_a$)=11.5 V,
armature resistance ($R_a$)=3.5 ?, armature inductance ($L_a$)=0.25 mH, motor constant ($k$)=0.26
N.m/A or V.s/rad, and equivalent rotor inertia ($J_{eq}$)= 5.4 ×$10^{-3}$ kg.m².
(a) Find the maximum armature current ($I_a$), the maximum angular speed ($\omega_{max}$), the starting
torque ($T_s$), the maximum power ($P_{max}$), and the starting angular acceleration ($\alpha_{max}$) of
the available DC servomotor.
(b) Verify if the available DC servomotor meets the required specifications. Draw the torque-
speed and the power-speed characteristics graphs of the DC motor, showing all relevant
values for each graph. Label the axes and specify units appropriately.
12 + 8
