/
/
Motor Basics

Motor Basics

Motor  Definition

The motor is an energy conversion device that converts electric energy into mechanical energy or mechanical energy into electric energy, using the magnetic field as media.
PMDC motor is an energy conversion device that converts electric energy into mechanical energy, using permanent magnetic field as media provided by permanent magnets like ferrite magnets and neodymium magnets.
Every motor needs two basic conditions to function: magnetic field and current.

There is a traditional classification to classify motors.
The Kinmore motors belong to the Permanent magnet DC motor.

Basic theories

The conductors (of finite dimensions) moving through a uniform magnetic field will have currents induced within them.
The direction of the current is judged by the right-hand rule and follows the equation: E=B*L*V
E: Electromotive force (Unit: V)
B: Magnetic flux density of the magnetic field (1 Tesla=104 Gauss)
L: Effective length of conductor (Unit: m)
V: Velocity of the conductor (Unit: m/s)
See figure 1 to the right, if we connect a lead wire to the conductor, the induced current will be generated.

The conductors with current within them will generate electromagnetic force in a magnetic field. The direction is judged by the left-hand rule and follows the equation: F=B*I*L
F: Electromagnetic force (Unit: N)
I: Current in the inductor (Unit: A)
B: Magnetic flux density of the magnetic field (Unit: Tesla)
L: Effective length of the conductor (Unit: m)
The left-hand rule is also known as the rule of the motor.
The right-hand rule is also known as the basic rule of the generator.

KCL ΣI=0: At any node (junction) in an electrical circuit, the sum of
currents flowing into that node is equal to the sum of currents flowing out of that node.
KVL ΣU=0: The directed sum of the electrical potential differences (voltage) around any closed network is zero.

The conductor with current within them generates a magnetic field around them. The direction of the magnetic field is judged by
the right-hand thumb rule and follows the equation: ∮H×dL=∑I=IA+IB+IC+…
H: magnetic field intensity (Unit: A/M)
L: Length of the conductor (Unit: M)
I: Current (Unit: A)

The total amount of energy in an isolated system remains constant over time.