MACHINES

• Supervised learning algorithms build models based on labeled data to make predictions.
• Electrical machine is a device which converts mechanical energy into electrical energy or vice versa.
• Electromotive Force (emf) is a description of the force exerted on particles due to electromagnetic fields.
• Magnetomotive force is a force that sets up a magnetic flux in a magnetic circuit.
• Permeability is the ability of a material to conduct magnetic flux through it.
• Flux is the number of magnetic lines of forces in a magnetic field.
• Maxwell is the unit of magnetic flux lines (red arrows from north to south show in the figure).
• Weber (Ф) is the SI unit of magnetic flux (10^8 maxwells).
• Flux density is the number of lines of flux per unit area (flux/sq meter).
• Tesla (β) is the SI unit of magnetic flux density.
• Series generators are used for arc lamps, as constant current generators, and as boosters on DC feeders.
• Differential compound generators have one of their important applications in electric arc welding.
• Some of the applications of separately excited generators are electro refining of materials or electro plating.
• The first commercially important application of electric power to driving mechanical energy was the DC distribution system.
• Separately excited generators have limitations because they need a separate excitation for the field winding.
• Shunt generators are used for lighting loads and battery charging.
• Brushless DC electric motors, also known as electronically commutated motors (ECM or EC motors), and synchronous DC motors, are synchronous motors powered by direct current (DC) electricity via an inverter or switching power supply which produces electricity in the form of alternating current (AC) to drive each phase of the motor via a closed loop controller.
• A stepper motor, also known as a step motor or stepping motor, is a brushless DC electric motor that divides a full rotation into a number of equal steps.
• Cumulative compound generators are used for domestic lighting and for energy transmission over a long distance.
• A solid state relay (SSR) is a relay that does not have a moving contact.
• Horsepower (hp), the common unit of power; i.e., the rate at which work is done.
• Torque is the rotational equivalent of linear force.
• Flemmings right hand rule is for DC generators (Lenz Law, Faraday’s Law).
• Flemmings left hand rule is for electric motors (Lorentz Force).
• Commutation in DC generator is the process in which generated alternating current in the armature winding of a dc machine is converted into direct current.
• The wire or conductor which constitutes the coil is called the winding in a DC machine.
• Brushes are used to collect the current due to the induced emf from the armature coils in a DC generator.
• Yoke is used to collect the current due to the induced emf from the armature coils in a DC generator.
• Rotor is the part in an electric motor that rotates.
• A Motor takes electrical power input and delivers mechanical power output at its shaft.
• Three-Point Motor Starters limit starting current by providing variable resistance.
• Wave Winding is a type of winding where the end of one coil is connected to the starting of another coil of the same polarity as that of the first coil.
• In Duplex Lap Winding, the number of parallel path between the brushes is twice the number of poles.
• An Overload Relay is a device that protects a motor from damages caused due to overloads and over-currents.
• Speed Regulation is the percentage rise in speed when mechanical load of the motor is removed.
• A DC Compound Motor is a combination of both a shunt-wound DC motor and a series-wound DC motor.
• A Shunt Motor brings an extremely efficient regulation for speed, while a Series Motor has a great and high starting torque.
• A Separately Excited DC Motor does not flow through the field windings, as the field winding is energized from a separate external source of DC current.
• A Relay is an electrically operated switch that consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals.
• A Series Wound DC Motor is a motor where the entire armature current flows through the field winding as it is connected in series to the armature winding.