Pico Electronics Limited

X10 Ltd.

David Richard Thompson

David John Rye

James R Phillips

Lesley Alan Leech

David C Campbell

An automated appliance control system includes a unit which transmits binary coded address and function control signals along the a.c. power line to a plurality of appliance control modules connected to the power line at various locations in the home. The binary coded signals transmitted along the a.c. power line are in the form of binary rf bursts which occur before and after the a.c. power line zero crossing points.

Appliance control

In the field of powerline carrier transmission and reception for remote control, a slave receiver counts cycles of carrier in a time window near to a zero-crossing of the power main. The receiver is implemented using discrete components (1,2,3) and a microprocessor. The discrete components form an input filter (1), a limiting preamplifier (2), a demodulator and noise filter (3) and, along with the microprocessor, a system (4) to detect the zero-crossing points. A capacitor is charged and discharged, depending upon the rate of occurrence of carrier cycles to produce a binary signal dependent on the digital value present on the carrier. By measuring the length of time the binary signal is in one of its states in said time window, the microprocessor determines whether the signal resulted from noise or not.

Remote control

A transmitter, for electrical appliance control by transmitting digital control signals on a power main, comprises two releasably connected parts, a first part comprising m actuators to initiate the generation of m control signals, and the second part containing a generator for the control signals, and a selector for selecting m out of n control signals. The selector is hidden by the first part when the parts are joined together and may be adjusted to select different groups of m control signals from the n possible signals. All n control signals can be produced, in groups of up to m signals for each condition of the selector. A monitor is also provided to monitor the main in order to achieve transmitter queueing dependent upon the selector settings at the transmitters.

Electrical appliance control

The switching circuit couples an appliance (1) to a power main (LN) via remotely controllable switching means (2) and is operable to change the state of the switching means (2) in response to a manual double switching of the appliance power switch so that the appliance can be manually switched ON after it has been remotely switched OFF. A capacitor (CAP1) generates from the mains voltage an alternating current signal of a phase differing from that of the mains voltage by an amount dependent on the external impedance across the output. The switching circuit monitors this phase difference and changes the state of the switching means (2) if it detects two phase difference changes exceeding a predetermined value in opposite senses within a predetermined time period, this being indicative of a manual double switching of the appliance power switch. The switching circuit does not operate spuriously for thermostatically controlled appliances nor in response to noise spikes.

Switching circuit for a remote control system

An applicance control system comprises a data transmitter and plurality of slave units plugged into outlet sockets of a power main of a building, appliances being coupled to the slave units. The transmitter housing includes a data input arrangement by which slave unit addresses and operation signal can be input and means for producing therefrom digital address and operation signals injected onto the main for receipt by the slave units. Each slave unit is enabled by a digital signal complying its address to effect an appliance operation as defined by a received digital operation signal.

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Fife, United Kingdom

David Richard Thompson