ELECTRONIC MOTOR AND GENERATORS

• Electricity is the phenomenon associated with the presence and motion of matter that have electrical charges.
• Electric Current is the movement of electrical charges. This can produce a magnetic field.
• Magnetism occurs when magnetic fields are formed. Objects that are magnetic can attract ferromagnetic materials which become magnetized as well.
• Metals like iron, cobalt, and nickel are ferromagnetic metals.
• Ordinary metals produce magnetic fields when a current flows through them.
• They behave like permanent magnets until the current stops. They are known as electromagnets.
• Electromagnetism is a branch of science that studies the electromagnetic force.
• The electromagnetic force is carried by EM fields which consist of electric fields and magnetic fields.
• James Clerk Maxwell is one of the early scientists who studied the interactions of positive and negative charges mediated by the electromagnetic force.
• Electrical charges attract or repel one another with a force inversely proportional to the square of the distance between them.
• Unlike (or opposite) electrical charges attract, while like (or similar) electrical charges repel.
• Magnetic poles attract or repel one another similar to electrical charges.
• These poles exist as pairs; every north pole is linked to a south pole.
• Direct Current – has one directional flow of electrical charges. This is typically used in battery-powered devices.
• Alternating Current – there is periodic reversal in the flow of electrical charges. This is the current used in wall sockets.
• An electric motor is a device that converts electrical energy into mechanical energy
• Electric motors use electromagnetism to generate torque (a twisting force that causes rotation).
• A Rotor consists of the moving parts of the motor.
• Power source – provides electrical power (usually DC power) to the motor. Power is delivered via the brush.
• An electric generator is a device that converts mechanical energy into electrical energy, the opposite of an electric motor.
• An electric generator operates on the principle of electromagnetic induction.
• Commutator – used to reverse the direction of current in the rotor.
• Stator – consists of the stationary parts of the motor.
• Michael Faraday discovered the principles of electromagnetic induction.
• Any change in the magnetic environment of a coil of wire will cause a voltage (or electromotive force) to be induced in the coil.