| 摘要 |
PURPOSE:To prevent a circuit part from being influenced by an external magnetic field by forming a casing to store the repeating circuit part of a repeater g or a heat radiation absorbing body structure with the material of a large magnetic permeability and a small residual magnetization as well. CONSTITUTION:When the casing 14 to store the repeating circuit part, is formed with the material of the large magnetic permeability and the small residual magnetization, the repeating circuit part in an internal part can be protected from the external magnetic field. When the heat radiation/shock absorbing body structure is fromed with the similar magnetic material as well, a similar effect can be obtained. Besides, when only a component or the circuit part 16, which are influenced by the external magnetic field, are covered by the part member 18 of the magnetic material of a similar property, the circuit part 16 can be effectively magnetic-field-shielded. Therefore, an optical submarine cable and the repeater are connected and the optical submarine cable is kept in a state that it is wound in a cable tank, and a system is switched on, and the whole system can be tested while it is watched, and a high reliability extending over a long term can be insured. |
