The torque/speed characteristics of 4 different brushed permanent magnet DC motor sizes from a motor manufacturer are given in the figure. The rated voltages, torques and speeds of each motor are also provided in a table below. 14000 12000 10000 Motor 1 Speed (rpm) Motor 2 8000 6000 4000 Motor 3 2000 Motor 4 0 5 10 15 25 30 35 20 Torque (mNm) Motor Rated Rated Rated Voltage rating Current Rated Rated Rated Starting Shaft electrical of the rating of the current Voltage Torque Speed Torque input converter converter Power (V) (mNm) (rpm) (mNm) power(W) (A) switches (v) switches (A) (W) Model Motor 1 14.5 10.0 9,730 Motor 2 12.0 1.96 8,400 Motor 3 14.0 4.9 4,520 Motor 4 11.0 1.47 9,700 Note: The unit mNm stands for millinewton meter Using the data provided in the table and the figure given above, complete the blank sections of table. Assume that all the motors are 75 % efficient at the rated operating points. Select a motor from the above list to drive a load that requires a maximum torque of 10 mNm and a maximum speed of 8000rpm, and briefly explain the reason. Draw a converter to be able to operate this motor to drive a remote controlled car which can go forward and reverse. Include freewheeling diodes in the converter. Select the voltage and current requirements for the transistors and the freewheeling diodes in the converter you sketched above to drive the motor you selected previously. The torque/speed characteristics of 4 different brushed permanent magnet DC motor sizes from a motor manufacturer are given in the figure. The rated voltages, torques and speeds of each motor are also provided in a table below. 14000 12000 10000 Motor 1 Speed (rpm) Motor 2 8000 6000 4000 Motor 3 2000 Motor 4 0 5 10 15 25 30 35 20 Torque (mNm) Motor Rated Rated Rated Voltage rating Current Rated Rated Rated Starting Shaft electrical of the rating of the current Voltage Torque Speed Torque input converter converter Power (V) (mNm) (rpm) (mNm) power(W) (A) switches (v) switches (A) (W) Model Motor 1 14.5 10.0 9,730 Motor 2 12.0 1.96 8,400 Motor 3 14.0 4.9 4,520 Motor 4 11.0 1.47 9,700 Note: The unit mNm stands for millinewton meter Using the data provided in the table and the figure given above, complete the blank sections of table. Assume that all the motors are 75 % efficient at the rated operating points. Select a motor from the above list to drive a load that requires a maximum torque of 10 mNm and a maximum speed of 8000rpm, and briefly explain the reason. Draw a converter to be able to operate this motor to drive a remote controlled car which can go forward and reverse. Include freewheeling diodes in the converter. Select the voltage and current requirements for the transistors and the freewheeling diodes in the converter you sketched above to drive the motor you selected previously
