Abstract: A gateway for an internet telephone system manages calls to and from personal computers and enables the personal computers to use the internet telephone system with an IP address assigned by a DHCP server or a private IP address. The gateway has a LAN receiver for processing an incoming call from the Internet or a personal computer, a line transmitter for processing an outgoing call to a telephone according to a request from the LAN receiver, a line receiver for processing an incoming call from a telephone, a LAN transmitter for processing an outgoing call to the Internet or a personal computer according to a request from the line receiver, and a logger for logging information about calls according to requests from the LAN transmitter and line transmitter.

Abstract: A gateway for an internet telephone system manages calls to and from personal computers and enables the personal computers to use the internet telephone system with an IP address assigned by a DHCP server or a private IP address. The gateway has a LAN receiver for processing an incoming call from the Internet or a personal computer, a line transmitter for processing an outgoing call to a telephone according to a request from the LAN receiver, a line receiver for processing an incoming call from a telephone, a LAN transmitter for processing an outgoing call to the Internet or a personal computer according to a request from the line receiver, and a logger for logging information about calls according to requests from the LAN transmitter and line transmitter.

Abstract: The present invention enables modulated wave signals having extremely small waveform distortion to be generated using a relatively simple circuit, and thereby it is possible to hold down vibrations and noise of a motor, which are attributable to torque ripples. In order to remove defects of the conventional techniques, the circuit generates a plurality of trapezoidal wave signals having at least two constant levels based on position sensing signals of magnetic pole of a motor, generates quasi-sinusoidal wave signals at a quasi-sinusoidal wave modulator based on the plurality of trapezoidal wave signals, and compares the quasi-sinusoidal wave signals with a carrier wave so as to perform PWM control of an inverter.

Abstract: In a network control apparatus which can dynamically control a bandwidth corresponding to a traffic status of a user flexibly, when a whole traffic quantity of a packet passing through the network exceeds a threshold value, per-user-information is analyzed based on a database holding packet information, and a bandwidth control method in conformity with the result of the analysis is selected to perform/release the bandwidth control.

Abstract: A gateway for an internet telephone system manages calls to and from personal computers and enables the personal computers to use the internet telephone system with an IP address assigned by a DHCP server or a private IP address. The gateway has a LAN receiver for processing an incoming call from the Internet or a personal computer, a line transmitter for processing an outgoing call to a telephone according to a request from the LAN receiver, a line receiver for processing an incoming call from a telephone, a LAN transmitter for processing an outgoing call to the Internet or a personal computer according to a request from the line receiver, and a logger for logging information about calls according to requests from the LAN transmitter and line transmitter.

Abstract: The present invention enables modulated wave signals having extremely small waveform distortion to be generated using a relatively simple circuit, and thereby it is possible to hold down vibrations and noise of a motor, which are attributable to torque ripples. In order to remove defects of the conventional techniques, the circuit generates a plurality of trapezoidal wave signals having at least two constant levels based on position sensing signals of magnetic pole of a motor, generates quasi-sinusoidal wave signals at a quasi-sinusoidal wave modulator based on the plurality of trapezoidal wave signals, and compares the quasi-sinusoidal wave signals with a carrier wave so as to perform PWM control of an inverter.

Abstract: A motor driving system is disclosed. The circuit includes a power converter for supplying a brushless motor having a permanent magnetic rotor with pulse-width modulation controlled driving power, a magnetic-pole position detector for detecting a magnetic-pole position of the motor rotor, a speed detector for detecting a rotational speed of the motor according to an output signal of the magnetic-pole position detector, a speed controller for outputting a deviation of an output signal of the rotational speed detector from a speed instruction, an instruction signal generating circuit for generating a plurality of instruction signals in response to an output signal of the speed controller, a circuit for generating modulated waves by selecting one of the plurality of instruction signals according to the magnetic-pole position of the motor, and a driving ct for controlling the power converter by means of pulse width modulation according to the modulated waves.

Abstract: The present invention aims at providing a TV receiver capable of relieving a burden to search for a TV program desired by a user and enabling the user to surely watch the TV program at a necessary time in a TV broadcast consisting a multiplicity of channels. The television receiver of the present invention comprises a receiving unit for receiving a television broadcast by selecting a specified broadcast channel from a plurality of broadcast channels, a control unit for controlling said receiving unit in order to receive the television broadcast of the specified broadcast channel, a means for receiving virtual channel information containing information for specifying a time zone and information related to the broadcast channel that should be selected in this time zone, a means for storing the virtual channel information, and a timer for notifying said control unit of a time.

Abstract: The present invention aims at providing a television receiver including a display screen capable of, in a television broadcast consisting of a multiplicity of channels, displaying information on programs being broadcast at other channels simultaneously with displaying an on-watching program. A television receiver of the present invention, comprises a screen including a channel name display area, a program schedule display area for displaying information containing a schedule of programs broadcast at channels displayed in the channel name display area, and a television broadcast display area for displaying the television broadcast received, and a display channel selection module for selecting the channel displayed in the channel name display area.

Abstract: A motor driving system according to the present invention comprises a power converter for supplying a brushless motor having a permanent magnetic rotor with pulse-width modulation controlled driving power; a magnetic-pole position detector for detecting a magnetic-pole position of the motor rotor; a speed detecting means for detecting a rotational speed of the motor according to an output signal of the magnetic-pole position detector; a speed control operation means for outputting a deviation of an output signal of the speed detecting means from a speed instruction; a means for generating a plurality of instruction signals in response to an output signal of the speed control operation means; a means for generating modulated waves by selecting one of the plurality of instruction signals according to the output signal of the speed control operation means; and a means for controlling the power converter by means of pulse width modulation according to the modulated waves.

Abstract: A driver circuit wherein a first switching element and a second switching element are totem-pole-connected, wherein the totem pole connection is connected at its one end, node and other end with a power source, an output to a load and a reference potential, respectively, wherein the first switching element is connected between the one end and the node, wherein the second switching element is connected between the node and the other end, and wherein a third switching element is connected between the one end of the totem pole connection and the control terminal of the first switching element.

Abstract: For a semiconductor circuit having one or more semiconductor devices, such as an IGBT, a turn-ON prevention circuit is provided for each device which prevents the device from turning ON during OFF times thereof, due to the presence of a transient voltage (dV/dt) across the main terminals of the device. In accordance with such a scheme, a MOSFET is connected between the insulated-gate electrode and emitter of the IGBT, and a capacitor, for example, is connected between the gate of the MOSFET and a sufficient electric potential to thereby effect a temporary turn-ON of the MOSFET to remove parasitic charge build-up in the IGBT before such charge build-up has reached a potential of the turn-ON threshold of the IGBT during OFF times of the IGBT. The capacitance element can be constituted by a MOSFET, namely, the capacitance across the gate-to-drain of an additional MOSFET.

Abstract: A squirrel-cage induction motor comprises a stator having a stator core and stator windings divided into first and second coils with different numbers of poles, and a squirrel-cage rotor including a rotor core and a plurality of rotor conductors embedded in the vicinity of the surface of the core. The number of the rotor conductors is the same as the average number of poles of the first and second stator coils, which conductors are arranged equidistantly along the periphery. This induction motor, with the construction of a squirrel-cage rotor, permits a variable speed operation without using any special device.