Capacitor Dictionary, Terms, and Definitions

Electric Double-layer Capacitor: Another name to refer to a Super-Capacitor.

Electrode A conductor, through which a current enters or leaves a capacitor.

Electrolyte Current-conducting solution (liquid or solid) between two electrodes or plates of a capacitor at least one of which is covered by a dielectric film.

Electrolytic Capacitor use two metal foils separated by an insulating paper. The metal foil is normally Aluminum. The paper and foils are rolled and impregnated with a liquid electrolyte. Aluminum Electrolytic Capacitors are polarized, and may be used DC circuits. Electrolytic Capacitors are used as 'bulk' de-coupling or board capacitors to supply a large discharge; however they react slow to change and are not well suited in high-speed circuits.
Typical values range form 0.1uF to 68000uF.
Standard Aluminum Electrolytic values change in multiples of 10, 22, 33, 47. The normal Temperature Coefficient [TC] for Aluminum Electrolytic Capacitors is +20%. [Electrolytic Capacitor Manufacturers]

Equivalent Series Inductance: [ESL] The inductance which is in series with the capacitor, primarily due to lead inductance. The graphic below shows the Lead Inductance as L (sub L).

Capacitor Equivalent Series Resistance

Equivalent Series Resistance: [ESR] The square root of the difference between the impedance squared and the reactance squared. All the internal resistance [losses] of a component [both series and parallel] treated as a single resistance at one point, at a given frequency. ESR allow the device to be described as a simple series R-C circuit. When possible always use low ESR capacitors. Normally a capacitor below .01uF are by definition low ESR. Normally ESR decreases with increasing temperature.

Capacitor Equivalent Series Resistance