Question

4. Find the correct motor property corresponding to each statement. Speed when no load and powered by Vnom Usually given in rpm (revs/min) The current required to spin the motor at the no-load condition. Nonzero because of friction torque. : The maximum torque achievable at the nominal voltage. Occurs at stall. The time for the motor current to reach 63% of its final value. Equal to LR The constant ratio of torque produced to current through the motor. Also called the torque constant

Answer 1

4) i. no load speed. it is the speed achieved by the motor at no load,

ii. no load current. the current applied to a motor at no load is known as no load current, it is generally very small and is used to overcome the internal frictions.

iii. maximum continuous stall torque. it is the maximum toque a motor can produce when stalled, in the long run, without damaging the motor.

iv. electrical time constant ($T_{e}$=L/R) it is the time needed for the current to reach 63% of its final value in response to a step input in voltage.

v. torque constant is similar to motor constant. motor torque constant simply is motor torque divided by armature current.