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Orthocyclic winding Orthocyclic wound coil Orthocyclic winding of a round coil Orthocyclic winding of a rectangular motor coil. This type of winding structure creates an optimal fill factor (90.7%) for round wires. The windings of the upper layer need to be placed into the grooves provided by the lower layer.
Coils are typically wound with enamelled copper wire, sometimes termed magnet wire. The winding material must have a low resistance, to reduce the power consumed by the field coil, but more importantly to reduce the waste heat produced by resistive heating. Excess heat in the windings is a common cause of failure.
In a "lap" winding, there are as many current paths between the brush (or line) connections as there are poles in the field winding. In a "wave" winding, there are only two paths, and there are as many coils in series as half the number of poles. So, for a given rating of machine, a wave winding is more suitable for large currents and low voltages.
A growler is an electrical device primarily used for testing a motor for shorted coils. A growler consists of a coil of wire wrapped around an iron core and connected to a source of alternating current. When placed on the armature or stator core of a motor the growler acts as the primary of a transformer and the armature coils act as the ...
The universal motor is modified in several ways to allow for proper AC supply operation. There is a compensating winding typically added, along with laminated pole pieces, as opposed to the solid pole pieces found in DC motors. [2] A universal motor's armature typically has far more coils and plates than a DC motor, and hence fewer windings per ...
The three coils are driven with each set 120 degrees in phase from the others. For the purpose of this example, the magnetic field is taken to be the linear function of the coil's current. The result of adding three 120-degree phased sine waves on the axis of the motor is a single rotating vector that always remains constant in magnitude. [17]
A synchronous motor may have a squirrel-cage winding embedded in its rotor, used to increase the motor starting torque and so decrease the time to accelerate to synchronous speed. The squirrel cage winding of a synchronous machine will generally be smaller than for an induction machine of similar rating.
A field coil may be connected in shunt, in series, or in compound with the armature of a DC machine (motor or generator). For a machine using field coils, as is the case in most large generators, the field must be established by a current in order for the generator to produce electricity.