Inductor
Inductor is a passive component designed to resist changes in current and is often referred as” AC Resistors”.The ability to resist changes in current and the ability to store energy in its magnetic field, account for the bulk of the useful properties of inductors. When current passes through an inductor, a magnetic field will produce. An alternately changing magnetic field produces an alternately changing electrical field, thus induces a voltage that opposes the field-producing current. The induced voltage across an inductor is calculated as follows:
V = L di/dt. Thus, the induced voltage is proportional to the inductance value and the rate of current change.
By its nature, an Inductor is a low pass filter, having the properties of letting low frequency signals pass and high frequency signals be blocked. At high frequency, the inductor becomes a high impedance element that can be used for RF isolation.
An inductor is magnetic component of energy storage, it also operates in the circuits for energy conversion, the energy stored in an inductor can be calculated using the following formula:
E = 1/2 L*I2 (Joule). An inductor is also used for impedance matching.
Coils and Chokes
Coils is another common name for inductors. Chokes is another name for an inductor used in signal or power lines which is intended to filter or choke out signals
Molded Inductors
An inductor whose case has been formed via a molding process. Common molding processes include injection and transfer molding. Molded inductors typically have well defined body dimensions which consist of smooth surfaces and sharper corners as compared to other case types such as epoxy coated and shrink wrap coatings.
Multilayer Inductors
An inductor constructed by layering the coil between layers of core material. The coil typically consists of a bare metal material (no insulation). This technology is sometimes referred to as “non-wirewound”. The inductance value can be made larger by adding additional layers for a given spiral pattern. Multilayer inductor is sometimes called Monolithic Inductor.
Ferrite Beads
Ferrite beads is a frequency dependent resistor and is used to help reduce noise. At low frequencies, inductive impedance is 10 ohm or less and the attenuation to the low frequency signal is limited. At higher frequencies, the impedance increases to over 100 ohms and becomes resistive above 100 MHz. The beads attenuates noise of unwanted frequencies through absorbing the noise signal and releasing in form of heat due to eddy current.
