Other Passives

This article is being split into components check for duplication prior to updataing

Inductors

An inductor is a passive electrical component that can store energy in a magnetic field created by the electric current passing through it. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries. Typically an inductor is a conducting wire shaped as a coil; the loops help to create a strong magnetic field inside the coil due to Ampere's Law. Due to the time-varying magnetic field inside the coil, a voltage is induced, according to Faraday's law of electromagnetic induction, which by Lenz's Law opposes the change in current that created it. Inductors are one of the basic components used in electronics where current and voltage change with time, due to the ability of inductors to delay and reshape alternating currents. Inductors called chokes are used as parts of filters in power supplies or to block AC signals from passing through a circuit.

equation here soon

If the rate of change of current in a circuit is one ampere per second and the resulting electromotive force is one volt, then the inductance of the circuit is one henry.

   \mbox{H} = \dfrac{\mbox{m}^2 \cdot \mbox{kg}}{\mbox{s}^{2} \cdot \mbox{A}^2} = \dfrac{\mbox{J}}{\mbox{A}^2} = \dfrac{\mbox{Wb}}{\mbox{A}} = \dfrac{\mbox{s}^2}{\mbox{F}} = \dfrac{\mbox{V} \cdot \mbox{s}}{\mbox{A}} = \dfrac{\mbox{J/C} \cdot \mbox{s}}{\mbox{C/s}} = \dfrac{\mbox{J} \cdot \mbox{s}^2}{\mbox{C}^2} = \dfrac{\mbox{m}^2 \cdot \mbox{kg}}{\mbox{C}^2} = \Omega \cdot \mbox{s}

units A = ampere C = coulomb F = farad J = joule kg = kilogram m = meter s = second Wb = weber V = volt Ω = ohm

Uses:

• tuned circuits: a circuit that responds in a special way to some frequencies( s ).
• power supply filter: remove the pulsing DC left from rectification or other noise in the signal.
• Decoupling: usually blocking high frequencies from one part of a circuit from getting in another part.
• boost buck regulators: voltage regulators that decrease or increase voltage.

Links

• Inductor From Wikipedia, the free encyclopedia

Transformers

Transformers are 2 or more inductors where the coils share the same magnetic field. This results in the current in one coil inducing a current in the other. They are commonly used to change the voltage from an AC source to a different voltage. We need much more description and information here. Would you add it?

Comments:

"Ferrites? I don't know much about 'em, I only use ferrites in switching regulators." --National Semiconductor's Bob Pease

Can be replaced in many circumstances with an impedance inverter using only an opamp, a capacitor, and a few resistors.