| 摘要 |
PURPOSE:To reduce crosstalk between extension telephone sets as much as possible by forming plural conductor layers on a mother substrate in different position relations at every attachment positions of plural LC substrates fitted to the mother substrate. CONSTITUTION:The conductor layers 12-15 formed on the mother substrate 11 are different in the position relation according to the attachment positions of the plural LC substrates 8a-8n attached to the substrate 11. Then, microcompters 10a-10n which control analog switches 9a-9n are connected to switches 9a-9n so that their address lines A-D correspond to the position relations of the conductor layers 12-15. This constitution reduces crosstalk between mutually close circuits and extension telephone sets greatly. |
