Abstract: A telephone interface circuit comprises a first transistor for controlling opening and closing between a speech circuit and subscriber lines, a second transistor for controlling the first transistor to turn on and off, a positive feedback circuit connecting a collector terminal of the first transistor and a base terminal of the second transistor, an overcurrent detection circuit detecting overcurrent applied to the subscriber lines, and a breaker circuit for turning off the first transistor by lowering the base potential of the second transistor to a low potential when overcurrent is detected at the overcurrent detection circuit. Here, the base terminal of the first transistor and a collector terminal of the second transistor are connected. Further, when off-hook, the base potential of the second transistor is controlled in such a manner as to become a high potential by a microcomputer.

Abstract: According to one embodiment, a repeater receives content data from a sender device through a first content protection technology and transmits the content data to another device through a second content protection technology. The repeater includes a receiver, a preparation module, and a transmitter. The receiver receives identification information that identifies a device compliant with the second content protection technology through the second content protection technology. The preparation module prepares an identification information list based on the first content protection technology that contains the identification information based on the second content protection technology received by the receiver and identification information based on the first content protection technology that identifies the repeater. The transmitter transmits the identification information list to the sender device through the first content protection technology.

Abstract: A telephone interface circuit comprises: a first transistor which switch-controls a connection between a speech circuit and a pair of subscriber lines; a second transistor which controls an on/off state of the first transistor; a positive feedback circuit which connects a collector terminal of the first transistor to a base terminal of the second transistor; and an internal power source which supplies current for driving the second transistor. A circuit constant is set such that the first transistor is to operate in a saturated region when a voltage in a range of voltage for normal use is applied in between the pair of the subscriber lines, and such that the first transistor is to operate in an unsaturated region when an overvoltage exceeding the range of voltage for normal use is applied in between the pair of the subscriber lines.

Abstract: According to one embodiment, a data transmission control section ends transmission of a title without copyright protection at time t2. When transmission time of the title exceeds prescribed time, interruption of the transmission is posted to a reception-side device, and a key discard/creation section creates a new encryption key. A copyright-protected title is transmitted to the reception-side device by using the new key.

Abstract: A transmitting apparatus transmits, to a receiving apparatus, a content that contains at least, in the stated order, a first portion that is encrypted with a shared key shared between the transmitting apparatus and the receiving apparatus, a second portion that is not encrypted, and a third portion that is encrypted with the shared key. In this situation, in the case where the encrypted third portion has become a transmission target after the second portion has been transmitted, and also, there is a possibility that the shared key stored in the receiving apparatus may be invalidated when the encrypted third portion is received, the transmitting apparatus sequentially transmits a fourth portion and the encrypted third portion to the receiving apparatus, the fourth portion containing at least element data that belongs to the last group in the second portion.

Abstract: A transmitting apparatus includes a transaction transmitting unit configured to transmit to a receiving apparatus a content to be moved to the receiving apparatus, by using a first transaction established with the receiving apparatus, a counter unit configured to count a progress quantity representing a degree of progress of the transmission of the content from a given point of time with respect to the transmission of the content corresponding to the first transaction to obtain a count value, and a transaction switching unit configured to switch the first transaction used for the transmission of the content to a second transaction, if the count value of the counter unit reaches a predetermined value and the transmission of the content is not completed.

Abstract: A telephone interface circuit has a first transistor for opening and closing a connection between a speech circuit and a pair of subscriber lines, a second transistor for controlling ON/OFF states of the first transistor, and a positive feedback circuit for positively feeding back, to a base terminal of the second transistor, a part of collector current flowing through the first transistor. A circuit constant is set such that when normal use voltage is applied to the pair of subscriber lines, the second transistor operates in a saturation region, and when voltage exceeding the normal use voltage is applied to the pair of subscriber lines, the second transistor operates in a non-saturation region.

Abstract: A hook switch turns on a transistor by connecting the positive electrode terminal of a capacitor to a base terminal of a transistor in an off-hook state, causing a speech circuit and telephone lines to be connected. The hook switch turns off the transistor by disconnecting the positive electrode terminal of the capacitor from the base terminal of the transistor in an on-hook state, causing the speech circuit and the telephone lines to be disconnected. A holding circuit holds the voltage at the positive electrode terminal of the capacitor at a substantially fixed value by charging the capacitor with electric power supplied from the telephone lines in an off-hook state.

Abstract: A telephone interface circuit comprising a speech circuit, a control circuit turning on upon receiving a supply of a forward direction trigger current so as to connect first and second telephone lines and the speech circuit, and going off upon receiving a supply of a reverse direction trigger current so as to disconnect the first and second telephone lines and the speech circuit, a capacitor charging and discharging charge supplied from the first telephone line, and a hook switch supplying charge accumulated at the capacitor when off-hook to the control circuit as a forward direction trigger current, and supplying charge discharged from the capacitor when on-hook to the control circuit as a reverse direction trigger current.

Abstract: A telephone interface circuit comprises a first transistor for controlling opening and closing between a speech circuit and subscriber lines, a second transistor for controlling the first transistor to turn on and off, a positive feedback circuit connecting a collector terminal of the first transistor and a base terminal of the second transistor, an overcurrent detection circuit detecting overcurrent applied to the subscriber lines, and a breaker circuit for turning off the first transistor by lowering the base potential of the second transistor to a low potential when overcurrent is detected at the overcurrent detection circuit. Here, the base terminal of the first transistor and a collector terminal of the second transistor are connected. Further, when off-hook, the base potential of the second transistor is controlled in such a manner as to become a high potential by a microcomputer.

Abstract: The object of the present invention is to remove the dead region of a diode bridge and maintain stable operations in a telephone terminal equipment interface circuit. In order to realize this object, a telephone terminal equipment interface circuit, according to the present invention comprises a diode bridge for rectifying line current supplied from a subscriber line and supplying the current to a call transmission/reception circuit, and a forward biasing circuit that supplies forward biased voltage to the diode bridge. Supplying forward biased current to the diode bridge makes the diode bridge operate in an activated state, thereby removing the dead region of the diode bridge and enabling more stable operations to be maintained in the interface circuit.

Abstract: A telephone interface circuit includes a speech circuit, a hook switch that opens and closes connection between a subscriber line and the speech circuit, an overvoltage detector that detects overvoltage input to the subscriber line, and a control circuit that controls the hook switch when overvoltage is detected by the overvoltage detector so as to open the connection between the subscriber line and the speech circuit.

Abstract: An object of the present invention is to provide a telephone interface protection circuit that has excellent standards of safety. In order to achieve this, the telephone interface protection circuit according to this invention comprises a voltage limiting element to limit surge voltages to no more than the withstand voltage of the circuit to be protected; and a positive temperature coefficient thermostatic resistor to limit the flow of overcurrents to the circuit to be protected. The voltage limiting element and positive temperature coefficient thermostatic resistor are thermally coupled together.

Abstract: The present invention provides an improved method of protecting a subscriber telephone interface circuit from the application of excess voltages and currents. The method uses a standard subscriber telephone interface circuit, including a speech circuit and a ringing detection circuit, in conjunction with updated controlling software. When excess voltage or current is detected by the ringing detection circuit, a CPU disconnects the speech circuit. The speech circuit is reconnected when the excess voltage or current is removed. The present invention further provides a ringing detection circuit that connects a speech circuit when a ringing signal is detected, and disconnects the speech circuit when excess voltage or current is detected.