| 摘要 |
PURPOSE: An Internet/trunk combinable telephone set is provided to use a generic wire/wireless telephone as an Internet phone by connecting it to a trunk telephone network and the Internet. CONSTITUTION: A ring/audio signal detection unit(10), composed of a coil(L2), the first amplifier(11) and an A/D converter(13), detects whether a ring signal from a trunk line and an associated response signal are generated, and outputs relevant data. The coil(L2) is wound with a coil(L1) connected to a trunk call path(1). The first amplifier(11) amplifies the current induced to the coil(L2). The A/D converter(13) converts the analog signal amplified at the first amplifier(11) into a digital signal. A system controller(20) outputs a switching control signal and a ring signal generation control signal according to the data outputted from the ring/audio signal detection unit(10) and the data outputted from an Ethernet controller(85). The first switch unit(40) executes switching for the trunk call path(1) according to the level of a control signal outputted from the system controller(20). The second switching unit(50), if the trunk call path(1) is interrupted by the first switch unit(40), executes switching for a telephone power supply line connected to a power generation unit(45) and supplies power to a telephone(70). A ring/audio signal generation unit(60) is comprised of a D/A converter(61), the second amplifier(63), and a coil(L4). The D/A converter(61) converts a digital control signal outputted from the system controller(20) into an analog signal. The second amplifier(63) amplifies the signal outputted from the D/A converter(61). The coil(L4) induces the current amplified at the second amplifier(63) to a coil(L3) connected to the trunk call path(1).
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