312results about "Transmission/receiving by adding signal to wave" patented technology

A PFC circuit modulating a power line using pulse width modulation (PWM) to drive a power MOSFET and series inductor across the power line. Since many modern electronic systems include a power factor correction circuit (PFC) that already includes a series inductor and power MOSFET, a PLC is incorporated into a controller to inject a PLC transmit signal into a control loop for the PFC circuit. This can be done using either an analog PFC controller, such as the UCC28517, the UCC2819A, or a digital PFC controller such as based on a TMS320C24xx DSP.

A system and method for broadband communications over power lines has a low-voltage transformer for the house connection unit and / or the electricity distribution inside the house. The system method allow for several parallel asynchronous data communications in different sub-channels with individual transmit power in each sub-channel. Sub-channel separation uses pass-band filters with high stop-band attenuation. High data rate in each sub-channel is achieved through the use of discrete wavelet multi-tone modulation. Coarse synchronization in each sub-channel and the optimization of the coefficients of the time-domain equalizer are carried out using a training sequence.

A pressure sensor portion includes a plurality of pressure sensors arranged in a plurality of rows and a plurality of columns inside a pressure-sensor-equipped carpet. The pressure sensor portion senses a pressure applied to the surface thereof and outputs a pressure value to a control portion. In an initial learning mode, a storage portion stores, as an initial value, the pressure value output from the pressure sensor portion. In a sensing operation mode, the control portion outputs to a modem portion a data signal indicating that an abnormal event is sensed, when the pressure value output from the pressure sensor portion is larger than the initial value stored in the storage portion by at least a prescribed threshold value. The modem portion superimposes the data signal received from the control portion on a power carrier wave (with a frequency of 50-60 Hz) and outputs the data signal to a power supply plug.

An endpoint processor includes a processor block, a timer block, a memory block, and analog-to-digital converter. The timer block is arranged to provide a time based signal to the processor block. The memory block cooperates with the processor block. The analog-to-digital converter is arranged to provide an interface between an analog signal and the processor block. The analog signal includes encoded data from a power signal. The processor block is arranged to control a sampling rate that is associated with the analog-to-digital converter such that the analog signal is down-converted as an under-sampled signal. The processor block is arranged to extract the encoded data from the down-converted signal by executing a digital signal processing algorithm that is stored in the memory block. The digital signal processing algorithm is arranged to reject fundamental and harmonic frequencies that are associated with a power-line frequency that is associated with the power signal.

An information terminal incorporates a network interface and an extension interface, and in the case of outside call, an audio send signal is modulated into an audio signal frequency band, and sent to the exchange through a private telephone line and a subscriber's line by way of the network interface. An audio receive signal sent from the exchange through the subscriber's line and private telephone line is demodulated into an ordinary audio frequency band through the network interface. On the other hand, in the case of extension service, an audio send signal is converted into a packetized digital signal by an extension interface circuit, and is further modulated into a higher frequency band so as not to overlap with the audio signal frequency band, and is transmitted through the private telephone line.

A system for independent control of electric motors and electric lights includes a plurality of two-wire wallstations coupled in series via power wires between an alternating-current (AC) source and a light / motor control unit. The light / motor control unit is preferably located in the same enclosure as an electric motor and an electric light and has two outputs for independent control of the motor and the light. The light / motor control unit and the wallstations each include a controller and a communication circuit that is coupled to the power wiring via a communication transformer and communicate with each other using a loop current carrier technique. The light / motor control unit and the wallstations utilize pseudo random orthogonal codes and a median filter in the communication process.