Characteristic parameters of film capacitor

1. Nominal Capacity: The nominal capacitance is the capacitance that is marked on the capacitor. Allowable deviation: The large deviation range allowed by the actual capacitance and the nominal capacitance. Generally divided into 3 levels: I grade ± 5%, grade II ± 10%, grade III ± 20%. In some cases, there is a level 0 with an error of ±20%;

2. Rated operating voltage: Rated operating voltage refers to the large DC voltage or AC voltage that can be continuously applied to the capacitor without damaging the capacitor within the specified temperature range. It can also be considered that the capacitor can work stably and reliably for a long time in the circuit, and the large DC voltage that is subjected to it is also called withstand voltage. For devices with the same structure, medium and capacity, the higher the withstand voltage, the larger the volume;

3. Leakage current: This is the specific specification of electrolytic capacitor. Generally, after pressing 3 min of the rated voltage of the capacitor itself, the current meter is tested in series, and the leakage current needs to be at 0. 01 CV (the uF capacitance value is multiplied by the rated voltage) or Below 3uA (take the larger value). For a specific low leakage current, the leakage current should be below 0.002 CV or below 0.4 uA;

4. Temperature range: plastic film capacitors are -40 ° C to +85 ° C. Ceramic capacitor T/C type is -40 ° C to +85 ° C, Hi-K type and S / C type is -25 ° C to +85 ° C;

5. Dielectric loss: The energy consumed by a capacitor to generate heat per unit time under the action of an electric field. These losses are mainly due to dielectric loss and metal loss. It is usually expressed by the loss tangent value. It is equivalent to the ratio of the series equivalent resistance to the capacitance of 1/wC.