Cathode

特許 係属中 A cathode is the electrode from which a conventional current leaves a polarized electrical device. This definition is sometimes remembered using the mnemonic CCD for cathode current departs. A conventional current describes the direction that positive electronic charge move. [Electron]s have a negative charge, so the movement of electrons is opposite to the conventional current flow. Consequently, the mnemonic cathode current departs also means that electrons flow into the device's cathode.