摘要:
A transmitting controller is connected to a powerline and on command places a reference signal and a series of signal pulses in the powerline at a series of signal timing positions related to zero voltage crossing points so that the signals pulses are substantially in the powerline temporal quiet zone. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the reference and signal pulses. The signal pulses are compared to the position of starting reference pulses to determine in which signal timing position the pulses have occurred. Digital data is communicated over the powerline in accordance with the nature placement of the data pulses related to the reference pulse positions. The timing zone for transmission and signals is preferably about 500 to about 1000 microseconds away from zero voltage crossing.
摘要:
A transmitting controller is connected to an AC powerline and on command places a series of signal pulse in the powerline in a series of signal timing windows related to zero voltage crossing points so that the signal pulses are in the powerline temporal quiet zone. The receiving controller is connected to the powerline and has a filter circuit therein which filters away the powerline AC signal and noise to leave the sensed pulses. The sensed pulses are compared to zero voltage crossing points to determine in which signal timing window the pulses have occurred. Digital data is communicated over the powerline in accordance with the placement of the signal pulses related to the particular timing window.
摘要:
An audio frequency power line carrier control system utilizing an inverter as the carrier control transmitter with the output phase voltages of the inverter fed to a distribution network through a series inductance, a filter circuit and a current transformer in which a starting control is provided which modulates the audio frequency pulses at the beginning of clock pulses for transmitting data using a control signal which is pulse width modulated, modulation being terminated when the pulse width of the control pulse width falls below a predetermined minimum duration thereby permitting small series inductances to be used.
摘要:
A method of and apparatus for generating in a power supply system a transmission signal with a frequency bearing a fixed relationship to the mains frequency of the power supply system. An impulse sequence whose repetition frequency bears the aforementioned fixed relationship to the mains frequency is formed by frequency multiplication and frequency division. A tank circuit connected to the power supply system and tuned at least approximately to the said repetition frequency is excited by it into oscillation in each cycle of the impulse sequence.
摘要:
A method for causing, in a power distribution network, an oscillation allowing data to be transmitted, includes connecting at least one capacitive load in series with a modulation circuit between two wires of the network. The amplitude modulation circuit includes at least one Zener diode and at least one switch. A short make pulse is applied to the switch such that it is conductive and short-circuits the Zener diode by modulating the amplitude of the network voltage. The duration of the make pulse is such that the amplitude modulation of the network voltage causes a response of the network in the form of a high-frequency oscillation of the network voltage.
摘要:
An adapter to reduce the effects of cross phase communication between a PLC transmitter plugged into one of the L1 or L2 power lines of a home and a PLC receiver plugged into the opposite L2 or L1 power line includes a housing with one side configured as a 240 volt plug and an opposite side configured as a 240 volt, so that the adapter can be plugged into a 240 volt wall socket and a 240 volt appliance plugged into the adapter. A coupler or a repeater is in the adapter and extends between the L1 and L2 lines to reduce attenuation of a communication signal from the transmitter or alternatively to amplify the signal and send it on to the receiver. A high frequency filter can be interposed between the coupler and the 240 volt appliance to prevent noise from the appliance from entering the communication signal and for preventing communication signals from entering the appliance.
摘要:
A coupling circuit is disclosed having a series connection of a first transistor (2) and a controlled current source (3). A transmission line (17) is connected to the junction of the first transistor (2) and current source (3). A signal I/O terminal of a signal processing device (1), acting as both input and output, is connected via a first resistor (4) to the base of the first transistor (2). A control output S of the device (1), which presents a signal establishing the transmission direction, is connected via a second resistor (5) to the base of the first transistor (2). The transmission line (17) is connected via a third resistor (6) to the signal I/O terminal of the device (1). This coupling circuit can be used both for transmitting and for receiving signals, the impedance being low in the transmitting direction and high in the receiving direction. The coupling circuit requires only two connections to the signal-processing device, this being advantageous, in particular, when using large scale integrated circuits.
摘要:
A solid state remote monitoring transmitter which transmits a 40 bit word that contains status information about a transformer via the secondary of a power distribution network to a central receiver associated with the primary (feeder) cable supplying the transformer. A program card specifies the carrier signal frequency and the identification of the transmitter. Multiple ananlog inputs are switched through a multiplexer to an A/D converter, the output of which is stored in a shift register to form the 40-bit word. The word is DPSK - coded by clock pulses in synchronism to the 60 Hz zero crossings of the AC power source and amplified by an unregulated power supply which is also powered by the AC power source. The phase transitions of the DPSK - coded word occur at the zero crossings diminishing any transients in the transmitter circuitry which would be caused by the phase transitions.
摘要:
A power line control circuit receives audio-frequency signals from a pulsed inverter that is transformer-coupled to the power line. A filter circuit is connected between the inverter and the coupling transformer primary circuit to transmit the audio signals and prevent power line frequencies from reaching the inverter. A magnitude-measuring circuit determines when output current from the inverter exceeds a certain value and controls an intervening circuit to reverse, briefly, the state of conductivity of the inverter.