| 摘要 |
PURPOSE: A DC voltage generation device and a DC voltage stabilizing method are provided to use a clamping circuit when more than 100V message wait voltage is required, thereby generating sufficiently high level of DC voltage without increasing a virtual value of a ring signal whose power is restricted. CONSTITUTION: A clamping circuit(410) receives an AC ring signal, and changes a peak value of the received AC ring signal into a certain reference level. A DC voltage generator(420) converts the signal transmitted from the clamping circuit(410) into regular size of DC voltage. A relay circuit(430) supplies the converted DC voltage to a telephone by corresponding to a relay control signal transmitted from a CPU of a main processor board, and connects with a neon lamp of the telephone. The relay control signal is controlled in time-division method. If the relay circuit(430) is connected with the neon lamp of the telephone, light of a message wait lamp is regularly turned on for a predetermined time.
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