| 摘要 |
A ring generator capable of supplying a plurality of predeterminedly selected distinct voltages each having a predetermined high amplitude and a predetermined frequency to a telephone line comprises a programmable computer having a low amplitude version of the plurality of voltages stored therein in digital form, the computer being responsive to predetermined control signals to select a desired one of the low amplitude version of the plurality of voltages stored therein, a first circuit arrangement coupled to the computer to convert the select one of the low amplitude version of the plurality of voltages to an analog version thereof and to increase the analog version to the predetermined high amplitude prior to coupling to the telephone line and a second circuit arrangement coupled to the first circuit arrangement, the telephone line and the computer to monitor the selected one of the plurality of voltage coupled from the first circuit to the telephone line to detect the operating condition of the ring generator and the telephone line.
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