Suntan Leakage Current Resistance of Aluminum Electrolytic Capacitors
When DC voltage is applied, leakage current flows through a capacitor. The leakage current of aluminum electrolytic capacitors is larger than other types of capacitors; furthermore, the leakage current changes according to the temperature, applied voltage and application time. If considering an equivalent circuit, the leakage current can be thought as the current flows through a resistance, which is connected in parallel to a capacitor. Leakage current becomes the power loss when capacitors are charged and self-discharge source when capacitors are discharged; therefore, it increases with error for the theoretical formulas.
The time constant in charge becomes lager than theoretical value and time constant in discharge becomes smaller than theoretical value. It is important to confirm that the capacitor meets the necessary requirements within the operating temperature range of the equipment, when using an aluminum electrolytic capacitor in a timing circuit.