Precautions when applying a voltage that is significantly lower than the rated voltage
Aluminum electrolytic capacitors may be used at the desired applied voltage provided the rated voltage is not exceeded. There is also no problem with applying a voltage that is extremely low relative to the rated voltage (hereafter referred to as low voltage).
(Example: Capacitor with a rated voltage of 450V used with a line voltage of 24V.)
Be careful of the following if using at low voltages.
- When voltage is applied to an aluminum electrolytic capacitor, the aluminum oxide, which serves as a dielectric, will repair itself.
When using a low voltage, the withstand to which voltage is not applied will not repair itself in locations that incur heat deterioration, etc. - This is not an issue if continuously used at a low voltage.
- If a higher voltage is applied after long-term use at a constant low voltage, there is the possibility of rapid current leakage from the location where the constant voltage was exceeded.
Characteristics of normal current leakage
The characteristics of current leakage change between the applied voltage and the rated voltage
- If current leakage increases, there is the possibility that the charge and discharge times assumed during the power source design phase may not be achieved. There is also the risk of capacitor heating or bloating.
- Products with a high rated voltage may have an ESR/impedance that differs from products with a low rated voltage due to the difference in materials used (with products of the same type, the product with the higher rated voltage will have a higher resistance).
Make sure you carefully evaluate the product when considering use. - The capacitance relative to ambient humidity and the rate of change in ESR/impedance may differ between products with a high rated voltage and products with a low rated voltage due to the difference in materials used.
Make sure you carefully evaluate the product for the assumed operating environment when considering use.
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