There is an electrolyte material inside an electrolytic capacitor that stores charges, with positive and negative polarity, similar to a battery and cannot be connected in reverse. The positive electrode is a metal substrate adhered with an oxide film, while the negative electrode is connected to the electrolyte (solid and non solid) through a metal electrode plate. Non polar (bipolar) electrolytic capacitors adopt a double oxide film structure, similar to two polar electrolytic capacitors that connect two negative electrodes. The two electrodes are connected by two metal plates (both coated with oxide films), and the electrolyte is in the middle of the two sets of oxide films. Polarized electrolytic capacitors usually perform power filtering and decoupling in power circuits or medium and low frequency circuits（ ǒ u) Signal coupling and time constant setting, DC isolation, and other functions. Non polar electrolytic capacitors are commonly used in audio frequency divider circuits, television S correction circuits, and single-phase motor starting circuits. The working voltage of electrolytic capacitors is 4V, 6.3V, 10V, 16V, 25V, 35V, 50V, 63V, 80V, 100V, 160V, 200V, 300V, 400V, 450V, 500V, and the working temperature is -55 °~+155 ° C (4-500V). They are characterized by large capacity, large volume, and polarity, and are generally used for filtering and rectification in DC circuits. The most commonly used electrolytic capacitors currently include aluminum electrolytic capacitors and tantalum electrolytic capacitors. The nominal capacitance is the capacitance marked on the capacitor. The basic unit of a capacitor is Farad (F), but this unit is too large and is rarely used in field labeling