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

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In summary, the commutator in a DC motor converts DC current to AC current, which is necessary for the motor to rotate continuously. This is because as the coil (or armature) rotates, the current needs to flip direction in order to keep the motor rotating. While a rectifier circuit could potentially be used in place of a commutator, it is more advantageous to use a commutator as it results in less mechanical wear and sparks. The rotating part of a motor is called the "armature" from an electrical perspective, and the "rotor" from a mechanical perspective.
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theBEAST
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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?
 
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  • #2
It is the other way around. In DC motors, DC is converted to AC by the commutator. Do you understand why this is done?
 
  • #3
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.
 
  • #4
voko said:
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.

BvU said:
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?
 
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  • #5
Yes. Definitely. Advantageous too: less mechanical wear, less sparks etc.

Beautiful video.
 
  • #6
theBEAST said:
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".
 

What is the difference between AC and DC?

AC (alternating current) and DC (direct current) are two types of electrical current. AC alternates direction periodically, while DC flows in one direction continuously.

Why would someone want to convert from AC to DC?

AC is the type of current that comes out of most power outlets, but many electronic devices require DC power to function. Therefore, to use these devices, AC must be converted to DC.

How is AC converted to DC?

AC can be converted to DC using a device called a rectifier. This device uses diodes to convert the oscillating AC current into a smooth, unidirectional DC current.

What are the advantages of using DC over AC?

DC has several advantages over AC, including the ability to be easily stored in batteries, the ability to provide a constant voltage, and the ability to be easily converted to different voltages. It is also less susceptible to power loss over long distances.

Are there any disadvantages to converting from AC to DC?

One potential disadvantage is the cost of the rectifier and other components needed to convert AC to DC. Additionally, converting from AC to DC may result in some power loss and increased heat generation. However, the benefits of using DC often outweigh these potential drawbacks.

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