Question:
A DC Motor, when supplied from a 195V power supply is observed to rotate under no load conditions at 1730 rpm. A stall test shows that the winding resistance is 1.66 Ω. The motor is connected to a load whose torque-speed characteristic is Torque = 0.128 × ω.
Find the speed (in rpm) at which the motor will drive the load.
So far, I have tried to use the following method:
$$\ K= \frac{V}{\omega} = \frac{195}{1730*\frac{2\pi}{60}} = 1.0764 $$
$$\ Torque= K*I = 1.0764* \frac{195}{1.66} = 126.4446 $$
And from the question, \$Torque = 0.128 \omega\$
$$\ \omega = \frac{126.4446}{0.128} = 987.85RPM $$
Can anyone tell me why this is wrong?
Best Answer
There are two errors:
What you should do: