**Explaining
Reactance:**

**Critical points to
consider about Inductance and Capacitance:**

Everything about Capacitors is totally opposite of an Inductor!

Inductors and Capacitors
**Store Energy** in their respective fields.

They do not Dissipate
(Transform) Energy like Resistance does, like in the form of heat, or radiation.

In an antenna, they give it
back to the XMTR, **rather than
Radiating it as Power Transmitted**.

In this case, the
antenna looks like **pure
resistance, **__at resonance__.

Inductors do not like
CHANGES in current. (they "React" to those changes, see also "Time Constants" below)

Capacitors do not like
CHANGES in voltage. (they "React" to those changes, see also "Time Constants" below)

In both cases the **RATE
of CHANGE** is critical.

This is why the formulas for
Inductive Reactance and Capacitive Reactance have **Frequency** as a
primary component.

Inductors oppose an increase
in current by producing a **C****EMF** against the suplied voltage

They also appear as an open
circuit __to the change__, to the source. (see L&C Comparisons)

Capacitors oppose an
increase in voltage by drawing __current__ from the source from the supply

They look like a short
circuit **to the change**, to the source. (see L&C Comparisons)

Inductors use the applied
energy to store it in an **ElectroMagnetic
Field**, as current begins to flow (increase).

Capacitors use the applied
energy to store it in an **ElectroStatic
Field** as the voltage charge increases (and current decreases).

As the "Rate of Change"
increases, as in the frequency that is applied, an inductor will
oppose the change in current more and more, therefore appearing as a
higher ohms value.

Hence the formula XL =
2*(pi)*freq*Henry

As the "Rate of Change"
increases, as in the frequency that is applied, a capacitor will
draw more and more current, therefore appearing as a lower
ohms value.

Hence the formula XC =
1/(2*(pi)*frequency*Farads)

(with the reciprical
relationship decreasing the Ohms as frequency increases)

**Examples:**

Power supply filter system (Concerns about "Inrush Current")

Low-Pass-Filter,
High-Pass-Filter, BandPass-Filter, Notch-Filter (Band-Pass-Reject)

Oscillator-Tuned-Circuits

Time Constants,

(more on Time Constants)

Automotive Spark coil (and
capacitor)

{ Windherst & VanDeGraph
Systems to charge a home-made capacitor }

Explaining_Reactance.html - ddf – WA7RSO – 09/21/2020