Suntan Blog

The Electric Double Layer Capacitors developed by Suntan are storage capacitors with highest capacitance values in the Farad range. They are among others suited to serve as batteries, can deliver considerably higher currents for a short time, however, and are maintenance free.

The construction of a Double Layer Capacitor can be described as a plate capacitor where the most important topic is to obtain electrodes with an extremely large surface. For this purpose activated carbon is ideally suited, as it allows to obtain capacitance values of up to 100F/g of the active mass of the electrode.

The electrolyte, the conductive liquid between the electrodes, is a conducting salt dissolved in an aqueous or organic solvent which permits to apply voltages of 2 V (in special cases 3 V).

The actual double layer consists from ions which attach to the electrodes - negative ions to the positive electrode and positive ions to the negative electrode - as soon as a voltage is applied to the cell and thus create a dielectric of a few Angstrom only. According to the formula for the capacitor from the dielectric constant of the double layer (approx. 10) and the extremely thin dielectric you get an very high capacitance value.

A well constructed multilayer ceramic capacitor chip is extremely reliable and, for all practical purposes, has no wearout mechanism when used within the maximum voltage and temperature ratings. Most failures occur as a result of mechanical or thermal damage during mounting on the board, or during subsequent testing.

Capacitor failure may also be induced by sustained operation at voltages that exceed the rated DC voltage, voltage spikes or transients that exceed the dielectric's voltage capability, sustained operation at temperatures above the maximum rated temperature, internal defects, or excessive temperature rise due to power dissipation.

As with any practical device, multilayer ceramic capacitors also possess an inherent, although low, failure rate when operated within rated conditions.The primary failure mode is by short-circuit or low insulation.

resistance, resulting from cracks or from dielectric breakdown at a defect site. Suntan monitors reliability with a periodic sampling program for selected values.

Aluminum Electrolytic Capacitors include axial, snap-in and screw-terminal types. These capacitors offer very long life in applications requiring high ripple currents and temperatures up to 150°C. Other models have rated voltages as high as 550 VDC.

In addition to those products shown in the datasheets, KEMET can optimize the construction to offer application-specific balance between required life, temperature, ripple current, physical size, and cost.

Motor start capacitors are also offered.

A high performance electrolytic capacitor designed for automotive applications with high vibrations and high ambient temperatures.

An electrolytic capacitor with outstanding electrical performance. It is polarized with the negative pole connected to the case. The outer case has a plastic cover.

The low ESR is a result of a low resistive electrolyte/paper system. Together with the TDC thermal concept, this range has very high ripple current capability. The capacitor is suitable for both mobile and aircraft applications, with operation up to 105°C.