Information

Design and specifi cations are subject to change without notice. Ask factory for technical specifi cations before purchase and/or use.
Whenever a doubt about safety arises from this product, please contact us immediately for technical consultation.
8
Gold Capacitors Technical Guide
Principles and Operation of Gold Capacitors
2-4 Electrical characteristics of Electric Double Layer capacitor
2-4-1 Electrostatic capacitance
The electrostatic capacitance of an electric double layer capacitor basically varies similarly as that of a battery under
the same use or test conditions and it is commonly referenced as the Effective Capacitance. This is commonly
referenced to as the Effective Capacitance.
As previously stated, the electric double layer capacitor is comprised of a small capacitor having various values of
resistance. Therefore, in order to measure the electrostatic capacitance, measurement parameters such as charge
voltage and charge time must be defi ned.
If the starting voltage is set slightly below the fully charged voltage value (V
0
), then the voltage down condition
(Fig.13) will occur at the start of the measurement. This is due to small capacitors with large internal resistance not
being fully charged which results in a large voltage drop at the start of the measurement. Under this condition, the
measured capacitance value will be small. However, by increasing the charging time, these small-high resistance
capacitors with high resistances will become charged and the voltage lost during the voltage down condition will be
small, resulting in a high measured value of capacitance (Fig.13).
Electrostatic capacitance is also current dependent. If a large amount of current is quickly discharged, or the
capacitor has been on discharge for a long period of time, the resultant electrostatic capacitance will be small.
Conversely, if the discharge current is small, or the discharge time short, the measured electrostatic capacitance will
be large. Therefore, in order to have measurement consistency we have adopted the standard discharge current of
1mA/F.