Can a rectifier circuit be used in a DC motor to convert AC to DC?

[theBEAST]

Homework Statement

I just learned that in a DC motor you use a commutator to convert the AC current to DC. And in my other course I learned that you can convert AC current to DC using a rectifier circuit. If this is the case, why don't we use a rectifier circuit in a DC motor to convert the AC to DC?

 

[voko]

It is the other way around. In DC motors, DC is converted to AC by the commutator. Do you understand why this is done?

 

[BvU]

I just learned that in a DC motor you use a commutator to convert the AC current to DC

You sure about this? Can you describe in a bit more detail what you think the commutator is doing and why ?

This isn't really homework with a 1,2 3 template, but asking for detail might help understanding the background and nature of this question.

 

[theBEAST]

It is the other way around. In DC motors, DC is converted to AC by the commutator. Do you understand why this is done?

Oh yeah you are right, in DC motors it is the other way around. I think I get it now, you need the commutator to give AC current so that as the coil (not sure if this is the right name for the rotating object, please correct me) rotates 180 degrees, the current will flip directly to keep it rotating.

You sure about this? Can you describe in a bit more detail what you think the commutator is doing and why ?

This isn't really homework with a 1,2 3 template, but asking for detail might help understanding the background and nature of this question.

It is because I initially saw a video on generators found here:


In this example, could I replace the commutator with a rectifying diode circuit?

 

[BvU]

Yes. Definitely. Advantageous too: less mechanical wear, less sparks etc.

Beautiful video.

 

[voko]

the coil (not sure if this is the right name for the rotating object, please correct me)

That is not wrong in general. There is more specific terminology for electrical machines, however. From the electrical point view, a coil would be called (part of) "armature" (note there may be more than one coil in general). From the mechanical point of view, the rotating part would be called the "rotor".