help me

[k2cr2o7]

please help me in calculating torque of a motor(300rpm) when there is nothing mentioned about the power of motor

 

[Nigel Goodwin]

please help me in calculating torque of a motor(300rpm) when there is nothing mentioned about the power of motor

I don't see how it's possible, you don't have enough information to calculate anything!.

 

[falleafd]

You can do some experiments to get the estimated values:

M is changed from 0 until the motor cannot turn.

R is constant

Apply voltage from 0 to maximum voltage. Maximum voltage is the voltage that run the motor in few minutes but dont make your motor warmer. (because to don't know the working voltage of your motor).

Calculate the Torque = M*g*R

Redraw the curve of Torque vs Voltage

You will see from 0 to Vmax, it has a nearly linear curve, but at the terminal (high voltage) you will see the horizontal line.

From the beginning of horizontal line, you will get the working voltage of your motor.

Apply this voltage to your motor and measure the current.

You will get the power of your motor: P = U*I.

And K = T/I (i dont remember exactly here, check it) is the const of electromotive of your motor. at Vworking max.

I = V/R

Then K = T*R/V

That is why you can redraw T vs V and find the linear curve.

Because T = (K/R) * V.

This is a very simple formula, and it's not correct, but you can estimate your torque vs voltage in this way.

 

[monttyle]

How much current does the motor draw?