Aluminum Electrolytic Capacitors

TECHNICAL NOTE1-4 Construction of DYNACAPThe basic cell construction of the DB, DBN, DX,DXJ, DH, DK, DBJ, DC, DCK, DS, and DSK seriesis similar to that of coin-type batteries as shown inFig.2. DYNACAP contains a single cell or two to threecells stacked in series.Since these series have a large electrode-to-electrodedistance and a small electrode area exhibiting a largeinternal resistance, they are suitable for the memorybackup application that involves microcurrentdischarge.The cylindrical cell construction as seen in the DZ andDZN series has the construction similar to that ofaluminum electrolytic capacitors as shown in Fig.3.Gasket Electrolyte CapELECTRIC DOUBLELAYER CAPACITORSThese series have a small electrode-to-electrodedistance, allowing a large electrode area because ofthe winding structure. This decreases the internalresistance, which is primary suitable for applicationsrequiring high-power such as motor drive and LEDlighting that need high currents.2 Description of Life ExpectancyGenerally, the life of Electric Double Layer Capacitorsis largely affected by the ambient temperature.The expected life is approximated by the equation asshown below:Where,Expected lifetime at temperature TLifetime at temperatureExpected working temperatureUpper category temperature®Activated carbonelectrodeSeparatorCaseNote that the above equation does not cover chargeand discharge. In the case of charge and discharge,heat generation occurs inside a capacitor; thetemperature rise by this heat generation must also beconsidered.Fig.2 Example of Basic Construction of Coin CellSeparatorActivated carbonelectrodeAluminumcaseSeal rubberTerminalElectric Double Layer CapacitorsTECHNICAL NOTEFig.3 Example of Basic Construction of Cylindrical CellCAT.No.2010/2011E