Contents

- 1 How do you count the number of rotations?
- 2 What is the principle of rotation of DC motor?
- 3 How can you tell if an array is rotated?
- 4 What is role of commutator in DC motor?
- 5 What causes a DC motor to count up or down?
- 6 How is the direction of a motor determined?
- 7 Is motor rotation from which end?
- 8 How do you find rotations per minute?

## How do you count the number of rotations?

The number of rotations N of the wheel is obtained by dividing the total distance traveled, 100 m = 10000 cm, by the circumference.

### What is the principle of rotation of DC motor?

Faraday’s principle of electromagnetism

Operating Principle DC motors operate on Faraday’s principle of electromagnetism which states that a current-carrying conductor experiences a force when placed in a magnetic field.

**How do you calculate the rotation speed of a DC motor?**

Motor RPM Calculation Examples

- (Hz x 60 x 2) / number of poles = no-load RPM.
- (60 x 60 x 2) / 4.
- 7,200 / 4 = 1,800 RPM.

**How do you find the number of rotations per second?**

Divide the number of revolutions,1000, by the number of seconds,3600, to get 5/18 revolutions per second. For comparison sake 60 mph is about 9.34 rpm. 5/18 rpm is about 1.75 mph.

## How can you tell if an array is rotated?

Approach:

- Find the minimum element in the array.
- Now, if the array is sorted and then rotate all the elements before the minimum element will be in increasing order and all elements after the minimum element will also be in increasing order.
- Check if all elements before minimum element are in increasing order.

### What is role of commutator in DC motor?

The commutator on the DC generator converts the AC into pulsating DC. On DC and most AC motors the purpose of the commutator is to insure that the current flowing through the rotor windings is always in the same direction, and the proper coil on the rotor is energized in respect to the field coils.

**What are the applications of DC motor?**

Application of DC Series motor

- Cranes.
- Air compressor.
- Lifts.
- Elevators.
- Winching system.
- Electric traction.
- Hair drier.
- Vacuum cleaner and in speed regulation application.

**How to control the rotation of a DC motor?**

When some threholds (in term of holes number) are specified, the main code receives interrupts each time a threshold is reached. 10 commands to start and stop the motor, increase and decrease the speed and turns number requirement, change the sens rotation (clock, counterclock) and for braking or not at the end of the rotation

## What causes a DC motor to count up or down?

A pulse on CW causes the counter to count up and a pulse on CCW causes the counter to count down. The counter is initialized to 127 (out of a max value of 255 to give it plenty of room to count up or down. The output is given via the SPI parallel output block to pins 12-20.

### How is the direction of a motor determined?

Note that the direction of the motor is already known from the encoder feedback signals from part 1. Typically, microcontrollers are used to implement PID controllers. They receive the input pulses from the encoder, then feed them through a control algorithm to output the motor speed.

**How does the speed of a motor vary with voltage?**

The speed of the motor varies according to voltage (like if I switch from 2AA batteries to 4AA’s) and weight (adding sensors slows the motors down). Every time I change voltage or weight, I have to guess how much voltage/time causes a single rotation.

**What is the rotation of motor?**

16.1.1 Physical parts of an electrical machine The rotation of the DC motor is accomplished by the force which is developed on a current-carrying conductor in a magnetic field. The current-carrying conductor is connected to the shaft which is able to rotate relative to the stationary body of the DC motor.

## Is motor rotation from which end?

If the shaft rotates to the left, your motor is counterclockwise shaft end, or CCWSE. To determine lead end perspective, hold your motor up and point the shaft away from you. If the shaft rotates to the right, your motor is clockwise lead end, or CWLE.

### How do you find rotations per minute?

revolutions per minute = speed in meters per minute / circumference in meters. Following the example, the number of revolutions per minute is equal to: 1,877 / 1.89 = 993 revolutions per minute.

**How can you tell if an array is sorted or rotated?**

**What is a rotated array?**

Array Rotation simply means shifting the array elements to the left or right of the array by specified positions. An array can be rotated to the left(clockwise) or to the right (anti-clockwise) to the given number of positions.