In the field of electronics reactance is called the barrier offered to the passage of alternating current through inductors (coils) or capacitors and is measured in ohms. The other two basic types of circuit components, transistors and resistors, have no reactance.
When alternating current flows through one of these two reactance-containing elements, energy is alternately stored and released in the form of a magnetic field, in the case of coils, or an electric field, in the case of capacitors. This produces a lead or lag between the current wave and the voltage wave. This phase shift decreases the power delivered to a connected resistive load after reactance without consuming power.
Capacitive reactance is the type of reactance that opposes voltage change, so current (i) is said to be 90 ° above voltage (v), so it represents this phase change in a sine diagram and / or phasors the current will go 90 ° ahead of the voltage.
There are two types of reactances:
- Capacitive reactance (XC) is the property a capacitor has to reduce current in an AC circuit. When a capacitor or electrical capacitor is inserted into an alternating current circuit, the plates become charged and the electrical current decreases to zero. Therefore, the capacitor behaves like an apparent resistance. But by virtue of being connected to an alternating electromagnetic field, it is observed that as the frequency of the current increases, the resistance effect of the capacitor decreases.
- Inductive reactance (XL) is the ability of an inductor to reduce current in an AC circuit. According to Lenz's Law, the action of an inductor is such that it opposes any change in current. Since alternating current is constantly changing, an inductor also opposes it, thereby reducing the current in an alternating current circuit. As the inductance value increases, the greater the current reduction. De la misma manera, dado que las corrientes de alta frecuencia cambian más rápido que las bajas, cuanto mayor es la frecuencia, mayor es el efecto de reducción. Donde la capacidad de un inductor para reducirlo es directamente proporcional a la inductancia y la frecuencia de la corriente alterna. Este efecto de la inductancia (reducir la corriente), se puede comparar en parte con el que produce una resistencia. Sin embargo, como una resistencia real produce energía térmica cuando una corriente eléctrica circula a través de ella, para diferenciarla se llama reactancia inductiva al efecto causado por la inductancia.
