Variable Inductor – A Dynamicuctor
The variable inductor was introduced in the 20th century. It has been used ever since as an electrical motor technology. It has a primary winding which may be wound up at variable speeds and it contains two coils of different length. The length of one of the coils determines the speed of the winding, while that of other one acts as a control. The main purpose of this binding is to provide an adjustable resistance to the force due to electricity flowing through it.
Variable inductor are characterized by their ability to undergo changes in the magnetic field. They help in the separation of the field components for a long period of time. The construction of this slug Tuned inductor consists of an arbor-like shaft, which is coated with metal. The outer form made up of materials such as plastic, phenolic, fiberglass, nylon, and ceramic is internally threaded. The innermost winding of the variable inductor is made from nonferrous material such as brass.
Variable inductor are widely used in communications systems for the transmission of radio waves. It is used in transceivers and in many electronic machines such as vacuum cleaner, TV, personal computers, automobile and aircraft motors, and RF circuits in mobile phones and personal computers. Another application of this indicator in communications system is the tuning of circuits for better performance and in lower cost of operation. For example, a circuit which is sensitive to high frequency can be tuned by using variable inductor. Another application is the detection of weak or active magnetic field near a metallic surface. For this purpose, some special types of variable inductor are designed, such as magnetic interferometer and multi-interferometer.
The various types of variable inductor are slugs-tuned inductor, fixed-slug inductor, balanced inductance (bezold), and slug-tuned inductor. In the former type, there is a variation of inductance between its two poles, whereas, in the latter type, there is no such variation. Likewise, the term’slugs’ refers to those units that are linear to its mean length; whereas ‘balanced’ refers to those that have an equal deviation. The units having an unequal deviation are termed as balanced. Thus, the term slug-tuned refers to the units having unequal variation in their mean length, while the term bezold refers to those having an equal deviation.
Fixed-slug inductor has similar characteristics with a slug-tuned inductor. In the former, there is only one primary winding formed by passing through two sets of contacts. In the latter, three primary winding is formed by passing through four sets of contacts. Slugs are formed by passing through a primary having a variable resistance, whereas balanced conductors are formed by passing through a primary having a constant resistance. Thus, both the primary and the secondary winding are capable of variable resistance, and hence can be used for multi-layer circuits.
Variable inductor can be of different kinds-monoblock, multi-layer, frequency variable, frequency-dependent, hybrid, and other types. Multi-layer inductors can be of any shape and any material-copper, gold plated, brass, bronze, steel. Frequency-dependent inductors can operate at higher frequencies than their counterparts. Hybrid inductors are used as a control device in RF circuits and electrical motors. While a frequency-dependent inductor controls a parameter, such as a current passing through, frequency-dependent conductors can also be used to control the resistance of a wire.