Abstract: A system and method for processing user speech commands in a voice interactive system is disclosed. Users issue speech phrases on a local device in a premises network, and the local devices first determine if the speech phrases match any commands in a set of local control commands. The control commands, in examples, can activate and deactivate premises devices such as “smart” televisions and simpler lighting devices connected to home automation hubs. In the event of a command match, local actions associated with the commands are executed directly on the premises devices in response. When no match is found on the local device, the speech phrases are sent in messages to a remote server over a network cloud such as the Internet for further processing. This can save on bandwidth and cost as compared to current voice recognition systems.

Abstract: An AC measurement circuit includes a rectifier for receiving an AC signal; a peak detection circuit; and a voltage divider, interconnected with an output of the rectifier, and the input of the peak detection circuit to provide the peak detection circuit with a voltage value equal to a fraction of the AC signal. An analog to digital converter, has its analog input interconnected with an output of the peak detection circuit, for providing a digital output corresponding to its analog input. A summing circuit sums n samples of the digital output. The voltage divider is configured so that the summing circuit calculates an average measurement of the AC signal by summing n samples and without floating point division.

Abstract: A displacement sensor for sensing displacement of a first surface relative to a second surface includes a coil mounted on the first surface, and encircling a region in plane; and a conductor extending lengthwise from the second surface through the region. The conductor has a volume that varies along its length. An AC source drives the coil to generate a magnetic field that pierces the region and induces eddy currents in the conductor. Eddy current losses resulting from the eddy currents vary in dependence on the volume of the conductor above and beneath the plane. A sensing circuit is coupled to the AC source to detect changes in eddy current losses, and thereby displacement. Detection of displacement may be used to signal tamper/intrusion. The sensor may further include a visual or audible output to signal such displacement.

Abstract: A system and method for processing user speech commands in a voice interactive system is disclosed. Users issue speech phrases on a local device in a premises network, and the local devices first determine if the speech phrases match any commands in a set of local control commands. The control commands, in examples, can activate and deactivate premises devices such as “smart” televisions and simpler lighting devices connected to home automation hubs. In the event of a command match, local actions associated with the commands are executed directly on the premises devices in response. When no match is found on the local device, the speech phrases are sent in messages to a remote server over a network cloud such as the Internet for further processing. This can save on bandwidth and cost as compared to current voice recognition systems.

Abstract: The embodiments disclose a circuit for detecting and determining a type of ground fault in a security system. An operational amplifier (OA) having positive and negative inputs and an output may receive AC input signals having different frequencies, f1 and f2 at a positive input and provide an AC output signal at the output. An OA feedback loop may comprise a ground fault equivalent impedance connected at the OA negative input and a feedback resistor connected between the OA output and the OA negative input. A rectifier may convert the AC output signal to a DC signal and a filter to obtain a steady DC voltage from the rectified DC signal. A steady DC voltage for two different AC input signals may be obtained and converted to a relative voltage with respect to a constant input voltage amplitude. The relative voltages may be compared to detect and determine a type of ground fault condition.

Abstract: A battery test circuit for testing batteries in a working circuit having a plurality of batteries includes a DC step up converter. The DC step up converter may be selectively interconnected between a first one of a plurality of batteries and a second one of a plurality of batteries, to draw a test current from the first battery and to supply current at an elevated voltage to the second battery. The test circuit further includes an indicator output for providing a signal indicative of whether the first battery provides the test current substantially at its rated voltage.

Abstract: A load limiting circuit includes a transistor switch, for providing current to a load and a latching circuit having a control input, and a latch output driving the transistor switch. A current sensing transistor interconnects with the transistor switch, to sense current in excess of a threshold to the load. The current sensing transistor drives the control input to the latching circuit. An external controller may drive and monitor the control input. The controller may thus turn the transistor switch on and off, and be notified of an over-current condition. The latching circuit may turn the transistor switch off permanently. As well, the controller may attempt to set the load limiting circuit after an over-current condition.

Abstract: A bi-directional current limiter may be configured to receive an AC signal and bi-directionally limit the loop current to a predetermined current value. A first and second zone may be configured in series with the AC signal and bi-directional current limiter. The first and second zone may include unidirectional current limiters to limit a unidirectional current that is proportionately less than the bi-directionally limited current. A first opto-coupler circuit (ISO1) may be configured to detect both high and low current states in the current loop circuit. Second and third opto-coupler circuits (ISO2 and ISO3) associated with the first and second zones may be configured to detect only high current states in the current loop circuit. The status of the first and second zones may then be determined by an analysis of the current level in the current loop circuit during two half cycles as determined by the various current limiters.

Abstract: A load limiting circuit includes a transistor switch, for providing current to a load and a latching circuit having a control input, and a latch output driving the transistor switch. A current sensing transistor interconnects with the transistor switch, to sense current in excess of a threshold to the load. The current sensing transistor drives the control input to the latching circuit. An external controller may drive and monitor the control input. The controller may thus turn the transistor switch on and off, and be notified of an over-current condition. The latching circuit may turn the transistor switch off permanently. As well, the controller may attempt to set the load limiting circuit after an over-current condition.

Abstract: A voltage measuring circuit includes a rectifier to receive an alternating current (AC) voltage to be measured and to provide a rectified output; a comparator for comparing the rectified output and producing therefrom a square wave having a pulse width indicative of the rectified output exceeding a threshold; a calculation circuit for converting a measurement of the pulse width into a measurement of the voltage and optionally an opto-isolator interconnecting the comparator to the calculation circuit. The rectifier may provide operating power to the comparator and an input side of the opto-isolator, from the AC voltage signal being measured. The remainder of the measuring circuit may powered by a source isolated from the voltage to be measured.

Abstract: A cabinet formed of a plurality of panels, includes a tamper detection system that includes an electrical circuit for detecting forming of a hole in a protected region of at least one panels. The electrical circuit includes at least one conductive trace on one of the panels. The conductive trace spans a protected region, wherein the minimum distance from any point in the protected region to the at least one conductive trace does not exceed some defined maximum. An electrical current source provides a current through the conductive trace. A sensor is in electrical communication with the electrical current source to sense a change in current provided to the trace and generate a tamper signal in response thereto.

Abstract: A displacement sensor for sensing displacement of a first surface relative to a second surface includes a coil mounted on the first surface, and encircling a region in plane; and a conductor extending lengthwise from the second surface through the region. The conductor has a volume that varies along its length. An AC source drives the coil to generate a magnetic field that pierces the region and induces eddy currents in the conductor. Eddy current losses resulting from the eddy currents vary in dependence on the volume of the conductor above and beneath the plane. A sensing circuit is coupled to the AC source to detect changes in eddy current losses, and thereby displacement. Detection of displacement may be used to signal tamper/intrusion. The sensor may further include a visual or audible output to signal such displacement.

Abstract: An alarm system comprises: an audio interface comprising: a microphone; a state sensor for sensing a state at the audio interface; a signal generator for generating an inaudible state signal indicative of the state; a multiplexer for combining an audio signal from the microphone and the state signal; a control panel for monitoring sensed conditions at the audio interface; a conductor interconnecting the audio interface to the control panel carrying audio signal and the state signal as combined from the audio interface to the control panel.

Abstract: An alarm system comprises: an audio interface comprising: a microphone; a state sensor for sensing a state at the audio interface; a signal generator for generating an inaudible state signal indicative of the state; a multiplexer for combining an audio signal from the microphone and the state signal; a control panel for monitoring sensed conditions at the audio interface; a conductor interconnecting the audio interface to the control panel carrying audio signal and the state signal as combined from the audio interface to the control panel.