Calculating torque within a DC MOTOR?

[Momento]

The torque that is generated inside a magnetic motor is caused from the magnetic forces that is this formula:

F = ILB

F: Magnetic force(Not sure what the unit would be...)
I: Current(A)
L: Torque(N.m)
B: Magnetic field.( Gauss or Tesla?)

I just need some help in calculating the total magnetic force I know the current & the magnetic field(measured in Tesla or Gauss in this cause?). However, the Torque is confusing for me to calculate... I've looked around and read theses slide countlessly but I really don't know how? I end up scratching my head all night wondering how to calculate the torque!

Thanks in advance!

 

[NascentOxygen]

Hi Momento. Suggest recheck your textbook (or the web) again to establish what that "L" quantity is.

 

[0110alxcpa]

My understanding is such that:

F = I l B (sin Θ = 1 )

where F = Newtons, I = amps, l = conductor length, and B = magnetic field strength in Tesla.
(remnant field strength may be .7 * max stated value)

You could also use a motor 'constant':

where torque in Nm/A = K * I, and BEMF = Kω

such that K = 2NBLR

where N = # of turns, B = Br*t/(t+g), L = active length (of stator), R = effective radius

where Br = remanent flux density, t = magnet thickness, and g = air gap

 

[Momento]

Hi Momento. Suggest recheck your textbook (or the web) again to establish what that "L" quantity is.

I'll give it a look.

My understanding is such that:

F = I l B (sin Θ = 1 )

where F = Newtons, I = amps, l = conductor length, and B = magnetic field strength in Tesla.
(remnant field strength may be .7 * max stated value)

You could also use a motor 'constant':

where torque in Nm/A = K * I, and BEMF = Kω

such that K = 2NBLR

where N = # of turns, B = Br*t/(t+g), L = active length (of stator), R = effective radius

where Br = remanent flux density, t = magnet thickness, and g = air gap

"(remnant field strength may be .7 * max stated value)"?

All the rest is really confusing... Could you simplify it more and more...?

 

[alphysicist]

Hello,

Calculating torque within a DC motor involves understanding the relationship between magnetic force, current, and magnetic field. The formula you have provided, F = ILB, is known as the Lorentz force law and is used to calculate the force on a charged particle moving through a magnetic field.

In this case, the force (F) is equal to the current (I) multiplied by the length of the conductor (L) and the strength of the magnetic field (B). The unit for magnetic force can be expressed in Newtons (N) or Ampere-meters (A.m). The unit for torque is Newton-meters (N.m).

To calculate the torque in a DC motor, you would need to know the length of the conductor (L) and the strength of the magnetic field (B). The current (I) can be measured using a multimeter. Once you have these values, you can use the formula F = ILB to calculate the magnetic force, and then use the torque formula, T = F x r, where r is the radius of the rotor, to calculate the torque.

It is important to note that the magnetic field strength (B) is typically measured in Tesla (T) in the SI system, or in Gauss (G) in the CGS system. To convert between the two, 1 Tesla is equal to 10,000 Gauss.

I hope this helps you in your calculations. If you have any further questions, please let me know. I am always happy to help others understand and apply scientific concepts.

Best regards,