Automatic phase adjustment of a pulsed electronic article surveillance transmitter is provided. Amplitude sampling of a received signal is used to detect the leading edge of a interfering transmit pulse and a corresponding delay is calculated for synchronizing the instant transmitter to the interfering transmitter. Detection of EAS tags placed too close to the EAS transmitter interrogation zone is also provided. An alarm can be implemented to indicate detected EAS tags that are placed too close ...

An article surveillance system includes a structure responsive to a first pulsed inductive magnetic field, periodically derived by a power line activated generator. The structure derives a second pulsed inductive magnetic field having a predetermined occurrence time relative to the occurrence time of the first magnetic field. A receiver for the second magnetic field is power line activated. The occurrence time of the first magnetic field and the activation time of the receiver to be responsive t...

In a supervisory system for detecting abnormal conditions, existing AC electric power supply lines are utilized and a plurality of resonance elements controlled by abnormal condition detectors are connected across the supply lines. High frequency currents of variable frequency are transmitted to the resonance elements over the supply lines and the high frequency current passed through the resonance elements are received by a receiver which is controlled such that it operates only in the regions ...

A power line carrier controlled lighting system connected to an AC power line. The system has: at least one motion detector for detecting at least one predetermined parameter in a detection zone of the motion detector, the motion detector outputting at least one detect signal in response to the predetermined parameter; at least one transmitter for transmitting during a first predetermined time period a power line carrier signal on the AC power line indicative of the detect signal; at least one r...

An electric power line communication system operates with an electric power distribution system to provide through premises power distribution lines highly reliable communication links among receiving devices electrically coupled or located in proximity to the premises power distribution lines. A power line transceiver is designed to transmit and receive through the premises power distribution lines modulated carrier signals conveying information over the communication links. The power line tran...

A house system for the transmission of information messages which are encoded in the form of digital signals wherein a code is selected which facilitates the testing of each information bit, including a central station and a series of substations at which the information messages of the central station are selectively deliverable through the electrical power supply wiring as the transmission path which is utilized by further similar systems. Each substation, due to an erroneously recognized info...

An arrangement for introducing audio-frequency signals into a power supply line containing a compensating capacitor, through a junction converter having primary winding which is connected with an audio-frequency signal generator. The secondary winding of the junction converter is connected in series with the compensating capacitors which are not located in a parallel branch line to the secondary winding of the junction converter, and thus do not represent a load on the audio-frequency signal. Th...

An endpoint is configured for communication with a distribution substation. The endpoint includes a receiver conditioning block and a receiver processing block. The receiver conditioning block is positioned downstream from the distribution substation, and arranged to provide an analog signal that is responsive to the power signal from the distribution line. The receiver processing block is configured to extract encoded data from the power signal by under-sampling the analog signal, and processin...

A method and apparatus for transmitting intelligence over a carrier wave are disclosed in which a signal waveform is added to a carrier wave to produce a composite wave having a recognizable pattern of variations in intervals that are defined by preselected locations in the composite wave. The pattern of variations in intervals resulting from the addition of the signal waveform to the carrier wave represents at least a portion of the intelligence to be transmitted over the carrier wave. The vari...

A control for a clothes dryer with an induction drive motor and an electric resistance heater element. A single sense winding is threaded through sensors monitoring drive motor current and heater current, generating an output voltage each time the alternating motor or heater current passes through a zero-crossing. The control monitors the ON/OFF condition of the heater and samples the lagging phase angle of the motor current, and provides an improved system of detecting when the clothes load is ...