時間：2011-03-11 23:13來源：藍天飛行翻譯 作者：admin 點擊：次
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electrolyte. A chemical solution, either a liquid or a gas, that conducts electrical current by releasing ions (unbalanced atoms) that unite with oppositely charged ions on the electrodes. Negative ions, atoms having an excess of electrons, move through the electrolyte to the positive electrode. Positive ions, atoms having a deficiency of electrons, move to the negative electrode. A lead-acid battery uses an electrolyte of sulfuric acid and water. When the battery is being charged, negative sulfate ions from the plates join positive hydrogen ions in the water and form sulfuric acid. When the battery discharges, negative sulfate ions leave the electrolyte and go to both plates. Positive hydrogen ions left from the sulfuric acid join negative oxygen ions from the positive plate and form water. The condition of charge of a lead-acid battery can be determined by measuring the specific gravity of the electrolyte with a hydrometer. The specific gravity shows the amount of acid in the electrolyte. electrolytic capacitor. A capacitor that uses metal foil for the electrodes and an extremely thin film of metallic oxide, a nonconductor, as the dielectric. Two sheets of metal foil separated by a piece of porous paper impregnated with an electrolyte are the plates. The dielectric is an oxide film formed on the surface of one of the plates. The capacity of a capacitor is inversely proportional to the thickness of the dielectric — the thinner the dielectric, the greater the capacity. And, since the oxide film is extremely thin, an electrolytic capacitor has a large capacity for its physical size. One major disadvantage of an electrolytic capacitor is its low DC working voltage compared with that of other types of capacitors. The thin oxide film can be easily punctured by a high voltage. An oxide film on a piece of metal acts as a rectifier. Electrons can pass from the metal through the film into the electrolyte. But they cannot pass from the electrolyte through the film to the metal. Because of this rectifying action, electrolytic capacitors must never be used in AC circuits, and they must be installed in a DC circuit with their anode, the terminal marked with a plus sign, connected to the positive voltage. electrolytic dissociation. The reduction of certain chemical compounds into their composite elements by passing electricity through them. When electrical current passes through water, it dissociates into hydrogen and oxygen. |
