10 MicroFarad Capacitor Used in 900 Series converter. Rated at 660 VAC Usually need one only. A capacitor is an electrical component which stores electrical charge. A capacitor has the effect of smoothing out or filtering a DC waveform, such as that which results from passing AC through recifier diodes. A battery will also perform this filtering function. The value of a capacitor is a measure of its charge-storage capability to capacitance, and is expressed in microfarads, which often abbreviated “uF”.