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Brushes and Commutator

Brush:   A  brush  or  carbon brush  is an electrical contact  which conducts  current  between stationary  wires  and moving parts, most commonly in a rotating  shaft . Typical applications include  electric motors ,  alternators  and  electric generators . The lifespan of a carbon brush depends on how much the motor is used, and how much power is put through the motor. Commutator:   A  c ommutator  is a rotary  electrical switch  in certain types of  electric motors  and  electrical generators  that periodically reverses the  current  direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating  armature  of the machine. Two Carbon Brushes  press against the commutator, making sliding contact with successive segments of the commutator as it rotates. The winding...
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Gramme Dynamo

A  Gramme machine ,  Gramme ring ,  Gramme magneto , or  Gramme dynamo  is an  electrical generator  that produces  direct current , named for its Belgian inventor,  Zénobe Gramme , and was built as either a  dynamo  or a  magneto .   Although popular in 19th century electrical machines, the Gramme winding principle is no longer used since it makes inefficient use of the conductors. The portion of the winding on the interior of the ring cuts no flux and does not contribute to energy conversion in the machine. The winding requires twice the number of turns and twice the number of commutator bars as an equivalent drum-wound armature. The Gramme machine used a ring armature, with a series of  armature   coils , wound around a revolving ring of soft  iron . The coils are connected in series, and the junction between each pair is connected to a  commutator  on which two brushes run. Permanent ...
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Induction Motor

Induction Motor   or machines are also called as  Asynchronous Machine . The word Asynchronous means that the machine never runs at synchronous speed. Induction motors are mainly of two types. It can be single-phase or three-phase induction motors.   Single-phase induction motor   is usually built in small size (up to 3 H.P). The three-phase induction motors are the most commonly used AC motors in the industry. They are simple in construction, reliable. It has low cost, high efficiency, reasonably good power factor, reliable, self-starting torque, and low maintenance. Almost more than 90% of the mechanical energy used in the industry is provided by three-phase induction motors. Three-phase induction motors  are mainly used in the industry for power conversion, i.e., electrical to mechanical power conversion in bulk or a large quantity. But for small power conversion single-phase induction motors are used. The induction motors perform a variety of services in the...
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VFDs and VSDs

  There are two primary methodologies for controlling electrical motors : - Variable Speed Drives (VSDs) : These drives change the speed of a motor by changing the input voltage and can be used with both AC and DC motors. - Variable Frequency Drives (VFDs) : Variable Frequency Drives also control the speed of a motor, but they do so by changing the voltage and frequency and can thus only be used with AC motors. Variable Speed Drives supply specific amperage and voltage to a motor. If the supply power is in AC form, VSDs utilize a rectifier circuit to convert the AC to DC at a specified voltage and amperage that the drive can adjust. Changing the voltage of the DC changes the speed of the motor. A DC motor VSD can consist of a very simple circuit, which makes them generally less expensive than VSDs. VFDs control the frequency and voltage of the AC signal. Adjusting the frequency  of an AC motor controls its speed, while changing the voltage will change the torque provided by th...
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