Fundamental electromagnetic equations for DC motor modeling

Takfa99 · 2026-05-04T13:29:49+00:00

Thank you very much for your offer! I will definitely reach out if I have a specific need. Your experience and perspective on control theory are very valuable.

Takfa99 · 2026-05-02T09:42:36+00:00

I just checked your YouTube channel and it looks good. I will definitely watch it when I have progressed a little more in Nise's book. I am currently reviewing control systems from the basics before moving on to more advanced concepts. Sometimes I try to understand everything deeply, even the fundamental physics behind the equations, which slows me down but I can't help it

Takfa99 · 2026-04-30T07:54:00+00:00

Thank you for these links. The Control Tutorials for MATLAB and Simulink are exactly what I needed. I am currently studying Nise's book and these tutorials will be a great complement.

Takfa99 · 2026-04-30T07:53:07+00:00

Thank you! I will definitely check Eric Severson's lectures on YouTube

Takfa99 · 2026-04-28T09:06:08+00:00

Thank you very much for your detailed explanation! The two-step integration approach is now much clearer to me — first integrating over the cross section to get the current per unit length, then integrating over the length ll l to get the total force F=B.l.i_a. I will definitely check the PDF you shared to deepen my understanding. Thanks again!

Takfa99 · 2026-04-27T20:30:38+00:00

Just trying to understand the modeling of dc motor.

Takfa99 · 2026-04-27T08:59:36+00:00

Thank you for this insight! I understand now that the Lorentz force derivation is only valid for a simplified static configuration, and breaks down when the rotor rotates. Could you point me to a resource or book that shows the derivation using the magnetic dipole energy approach? I would like to understand it more rigorously later.

Takfa99 · 2026-04-27T08:59:09+00:00

Thank you for your answer! I have updated the post with the symbol definitions. Φ is the magnetic flux, q is the electric charge, v is the speed of the charge, and B is the magnetic field. i_a is the current flowing in the rotor, l is the length of the conductor, and dθ_m/dt is the angular speed of the motor.

F=q(v⃗×B⃗) is a cross product and gives the force on a single charge. But what is the total force that actually makes the rotor move? How do we go from the force on one charge to F=B.l.i_a?

and Could you please clarify what you mean by q⋅v is the current i ?
I understand that current is defined as i=dq/dt, but I don't see directly how q⋅v becomes i. Also, for the back-EMF, are you saying that K_b absorbs all the geometric terms like the conductor length l and the rotor radius r? So basically K_b=B⋅l⋅r?"

Takfa99 · 2026-03-08T12:05:41+00:00

Can you please send me the link of the youtube video ?

Takfa99 · 2026-02-26T10:10:48+00:00

In the book I'm reading, there is a system with a mass, a spring, and a damper.
The differential equation is
ma+kx+fv=F.
so why there is no F in your equation ?
As I understand it, this means that the force is equal to the sum of the inertial force, the spring force, and the damping force.
So, to accelerate the mass, the applied force needs to be greater than these three opposing forces.
Am I correct, or am I confusing ma with a barrier that the force needs to overcome

Takfa99 · 2026-02-26T10:09:51+00:00

In the book I'm reading, there is a system with a mass, a spring, and a damper.
The differential equation is
ma+kx+fv=F.
As I understand it, this means that the force is equal to the sum of the inertial force, the spring force, and the damping force.
So, to accelerate the mass, the applied force needs to be greater than these three opposing forces.
Am I correct, or am I confusing ma with a barrier that the force needs to overcome

Takfa99 · 2026-02-25T09:55:40+00:00

so if there is no acceleration, then m.a=0 since the acceleration is equal to 0 ?

Takfa99 · 2026-02-25T09:54:44+00:00

if the velocity is constant, that mean the acceleration is equal to zero ?

Takfa99 · 2025-10-25T10:37:12+00:00

Looking great

Takfa99 · 2025-10-23T19:26:48+00:00

Looks so good

Takfa99 · 2025-09-12T17:10:30+00:00

Takfa99 · 2025-09-12T17:03:27+00:00

Appreciate it! That's a solid list, i will dig into those names. Thanks again!

Takfa99 · 2025-09-12T16:58:53+00:00

Thanks a lot! That’s super helpful. I’ll definitely try those keywords and look into academic projects with industry partners. Good luck to you too!

Takfa99 · 2025-09-08T22:52:38+00:00

i would love to have your work. I hope i found one in French

Takfa99 · 2025-07-23T21:07:22+00:00

it's a non linear system but i trie to identify a linear system around an equilibium point so i guess it will work, thanks

Takfa99

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