- #1

mp252

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thanks mayur

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- Thread starter mp252
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In summary, the first block diagram is a control system, and the second diagram is the model of the BLDC motor.

- #1

mp252

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thanks mayur

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- #2

berkeman

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mp252 said:

thanks mayur

Can you just scan the diagrams and upload them as PDFs? Or take a cell phone picture of them and upload them as JPGs?

- #3

- #4

DragonPetter

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The second block diagram is not a control system, it is ONLY the model of the motor. The feedback loop in the second block diagram is characteristic of all DC motors, because it is the natural back EMF feedback. When you apply the G/(1-GH) rule to a feedback, you get a closed loop transfer function, and that is what's used in the first block diagram. to represent HDD dynamics This combines the electrical and mechanical poles into one transfer function, and that's why you don't see a load block in the first diagram.

- #5

alphysicist

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Angular speed and angular velocity are both measurements of rotational motion, but they have slightly different definitions. Angular speed is the rate at which an object rotates, while angular velocity is the rate of change of the object's angular displacement over time. In other words, angular speed is a scalar quantity, while angular velocity is a vector quantity that includes direction.

In the context of the two systems you have described, the DC motor model and the BLDC motor model, both systems are using a PID controller to regulate the angular velocity of the motor. However, the DC motor model includes a load block, which represents the external load on the motor, and the BLDC motor model does not.

The reason for this difference is due to the different types of motors being modeled. A DC motor is a type of brushed motor, meaning it uses physical brushes to make contact with the commutator and provide power to the armature. This physical contact creates friction, which acts as a load on the motor and affects its rotational motion. Therefore, the load block in the DC motor model is necessary to accurately represent the motor's behavior.

On the other hand, a BLDC motor is a type of brushless motor, meaning it does not have physical brushes and instead uses electronic commutation to control the motor's rotation. Without the physical contact and friction from brushes, there is no external load acting on the motor. Therefore, a load block is not necessary in the BLDC motor model.

In summary, the presence or absence of a load block in a motor model depends on the type of motor being used and how it operates. The important thing is that both models are using a PID controller to regulate the angular velocity, which is the main goal of the systems.

Angular speed is the rate at which an object rotates and is measured in radians per second. Angular velocity, on the other hand, not only takes into account the rate of rotation but also the direction in which the object is rotating, making it a vector quantity. It is measured in radians per second in a specific direction.

Angular speed and linear speed are related by the formula v = rω, where v is the linear speed, r is the distance from the axis of rotation to the object, and ω is the angular speed. This means that as the object's distance from the axis of rotation increases, its linear speed also increases.

Yes, both angular speed and angular velocity can be negative. Negative angular speed indicates that the object is rotating in the opposite direction of the positive direction, while negative angular velocity indicates that the object is rotating in the opposite direction of the direction used to define the positive direction.

Angular velocity can be calculated by dividing the change in angular displacement by the change in time. It can also be calculated by dividing the tangential velocity (v) by the distance from the axis of rotation (r), giving the formula ω = v/r.

Some examples include a Ferris wheel, a spinning top, a record player, or a spinning figure skater. In each of these cases, the objects have both angular speed and angular velocity as they rotate around an axis.

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