| 摘要 |
PURPOSE:To provide a telephone line power utilization circuit where receiving efficiency is improved by controlling the input DC resistance of a DC-DC converter. CONSTITUTION:In a telephone line power utilization circuit 1 utilizing DC power to be supplied from the side of a telephone line as the power source of a line terminal equipment main body circuit TA by a DC-DC converter CN, a CPU 2 with AD converter controls the DC resistance RS of the line terminal equipment viewed from the side of the telephone line to be within the range where it satisfies a prescribed specification and the input DC resistance of the DC-DC converter CN to be a maximum. Thus, the DC power to be supplied from the side of the telephone line can be utilized to the maximum as the power source of the line terminal equipment. |
