Capacitors Home / CapacitorsCapacitorsImpedance of a capacitor – Capacitive reactance The Impedance of a capacitor (Capacitive reactance) is the measure of the opposition to a change of the electrical current in this component.What is a Capacitor? Capacitors are devices made of two metal plates separated by an insulator or dielectric. Charge, Voltage and Capacitance RelationshipDielectric constant / Relative Permittivity (Capacitor) What is the Dielectric constant / Relative Permittivity? The dielectric constant is the ratio of the permittivity of a substance to the permittivity of free space. It is a dimensionless physical constantCapacitors in Series – Capacitors in Parallel Capacitors in series – Capacitors in parallel. How to obtain the equivalent capacitance of series capacitors and parallel capacitors? Formulas and examplesElectrolytic Capacitor The Electrolytic Capacitor has been developed to achieve large capacities in small physical dimensions. To achieve this large capacity, a special dielectric is used.Capacitor Charging Process (RC circuit) Capacitor charging process. Capacitor charging process shows the variation of voltage and current in the capacitor over time, when it is connected to a DC voltage sourceCapacitor and Direct Current (DC) – Dielectric Capacitor and Direct Current. If a not charged capacitor is connected across the terminals of a battery, a transient current flows as the capacitor plates charge up.Capacitor Discharging Process (RC circuit) Capacitor discharge process. In a series RC circuit, a capacitor voltage Vc decreases from the initial voltage on the capacitor to 0 volts in some amount of time.Capacitor and the Alternating Current Capacitor and the Alternating Current. Unlike the behavior of a capacitor in direct current (DC), in the alternating current (AC) the current passes more easily through a capacitor.