Does the brushed DC motor and Permanent magnet Dc motor need position feedback in the control system

[mitardraskovic]

Hello guys. I am an electrical electronics engineering student. I have two questions. if you answer my questions ı'll be happy. Thank you from now.

Does the brushed DC motor need position feedback in the control system? why?

Does the permanent magnet dc motor need position feedback in the control system? why?

 

[Lucien Nunes]

Those questions don't make sense without context, and they also look like study questions which we won't answer for you although we'll help you answer them yourself.

If you mean position feedback to the drive electronics, then the difference lies in the method of commutation. How is a PM motor commutated? What governs the relationship between rotor position and which coil(s) are energised?

If you mean position feedback to the servo system itself, then the application dictates the answer. A lathe axis-drive and a fuel feed auger could both be part of a closed-loop control system, but only one requires positional feedback.

 

[oracle]

As noted above context is required, since you are an electronics student I suppose you are asking about DC motors, stepping motors and servo motors?

 

[Lucien Nunes]

the speed will be directly proportional to the armature current.

I think you meant to say voltage, not current!

But the OP asks about position feedback, not velocity feedback...

 

[oracle]

I think you meant to say voltage, not current!

But the OP asks about position feedback, not velocity feedback...

Thank you, edited and rephrased!

 

[mitardraskovic]

Thank you for your help. I want to explain my question again.
Is the position feedback required in the brushless and brushless DC motor control system? why?. That's the question

 

[Lucien Nunes]

How would you answer this question?

 

[Spoon]

Thank you for your help. I want to explain my question again.
Is the position feedback required in the brushless and brushless DC motor control system? why?. That's the question

Welcome to the forum mate.
If you give us your thought on the answer then we will give ours. That way you will learn more.

 

[PEG]

Hi,you have not explained the question,just re-asked it

More detail regarding the type of motor,and it's use and control,would be needed to provide an answer.

At the moment,we are at the "Do i need to wear a jumper?" stage...

 

[Silly Sausage]

Does the brushed DC motor need position feedback in the control system? why?

Does the permanent magnet dc motor need position feedback in the control system? why?

Are we suffering a poor computerised Turkish-English translation problem here?

Can you give us the FULL question?

 

[mitardraskovic]

The question of these electrical machines is 1 course. precisely this is the question of the teacher. You can think of as simple dc brushed and brushless motors. Does a simple dc motor need feedback? we usually use a compount motor.

 

[Deuce]

Thank you for your help. I want to explain my question again.
Is the position feedback required in the brushless and brushless DC motor control system? why?. That's the question

This isn't a complete question at all. There are literally billions of brush-less and brushed motors in everyday use without any position control. There must be more to this question than you're sharing.

But in any case, if you don't KNOW that you haven't asked enough to form a complete question, then what's the point in worrying about the right answer even if we could magically offer it to you? You still wouldn't know anything that you could apply in the real world.

I would suggest you hop over to the industrial electrical forum, that's where us automation geeks lurk... We're all too arsey to give you an easy answer, but some education might be forthcoming - if you learn how to ask a question

 

[PEG]

So as not to seem a miserable bunch...i am going out on a limb,and will suggest the question might be "Why would position control be required,on a ---- type motor..."

A reasonable answer to this,would be,that a device or machine,may have the requirement to start/finish a cycle type process,at a precise or pre-determined position.

There are a multitude ways of doing this,many combinations,and reasons why one method would be better than another,on the same motor.

This is why you would have to either frame the question within detailed parameters,or furnish us with the full picture.

Nevertherless...a happy Christmas

 

[Deuce]

So as not to seem a miserable bunch...i am going out on a limb,and will suggest the question might be "Why would position control be required,on a ---- type motor..."

A reasonable answer to this,would be,that a device or machine,may have the requirement to start/finish a cycle type process,at a precise or pre-determined position.

There are a multitude ways of doing this,many combinations,and reasons why one method would be better than another,on the same motor.

This is why you would have to either frame the question within detailed parameters,or furnish us with the full picture.

Nevertherless...a happy Christmas

I agree, but sadly the question appears to be not why, but what position control.

I am happy to be part of the aforementioned miserable bunch but the truth is, I see a student seeking knowledge and I do want to help.. It's just this particular student seems to have the question ahead of exam time, yet despite this apparent advantage has only bothered to post half of it here

I suppose the 'one size fits all answer' is 'electronics'. Frankly with enough tech you could pick up a 100 year old motor and have it stop in any position you wish, so long as there are step sensors in place and you have a rough characteristic of the motor, the electronics and programming can easily do the rest, even if reverse voltage braking is required, it's all possible.

For me the biggest problem is that the student is apparently less interested in posing the question accurately, than we are in answering it. I feel the student needs to pick up their game a little, unless they just want a pass, not an actual skill

And yes, Happy Christmas to you all

 

[Silly Sausage]

For me the biggest problem is that the student is apparently less interested in posing the question accurately, than we are in answering it. I feel the student needs to pick up their game a little, unless they just want a pass, not an actual skill

And yes, Happy Christmas to you all

I suspect he's spread bet every electrical forum on the web grasping for an answer. I've got a vague, hazy memory when I used to look at books, if you remember those things.