Abstract: A system for the detection and location for preventing underground infiltration and enable the timely discovery of tunnels and a rapid response is presented. It can therefore prevent prison escapes, attempts to infiltrate security facilities and others which must be protected. The system consists of a network of large-diameter adjacent pipes (1-4 meters, as required) buried underground either vertically or horizontally Inside each pipe there are sensors capable of detecting any foreign body entering the space. The sensors from all the pipes are connected to a control center to provide an immediate information on the location. The upper side of each of pipe has a lid that can be opened to check the source of the alarm and introduce personnel and equipment to handle the infiltrator.

Abstract: A pest control and/or detection system generally includes an electrically conductive bait matrix including at least one carrier material that is at least one of palatable, a phagostimulant and/or consumable and/or displaceable by pests, and a plurality of electrically conductive particles. The electrically conductive particles are substantially randomly interspersed throughout the at least one carrier material. The at least one carrier material includes a thermoplastic material and/or a resin.

Abstract: Various safety systems for power tools, and in particular table saws include detection systems for detecting a dangerous condition relative to a blade of the power tool, reaction systems for taking mitigation action in response to detection of a dangerous condition. The safety system may detect, prevent, and/or mitigate a dangerous condition associated with the power tool.

Abstract: In accordance with at least one embodiment, a method for detecting a liquid level includes providing a container (402) having a cavity, and disposing a sensor (102) in the cavity of the container (402), such that a ground pattern (310) on a first surface of the sensor (102) is positioned to contact a liquid in the cavity. A first electrode (104) and a second electrode (106) are located on a second surface of the sensor (102). The sensor (102) is coupled to a sensor input and a sensor driver. A cable coupling the sensor (102) to a touch sensor (116) comprises a shield line (112, 114) that is coupled to ground.

Abstract: A capacitive physical quantity sensor includes a first substrate, a movable electrode, a fixed electrode, a second substrate, a signal applying unit, a C-V conversion circuit, and an auxiliary electrode. The auxiliary electrode is disposed from a portion of the second substrate which faces the movable electrode to a portion of the second substrate which faces a displaceable region of the movable electrode. The signal applying unit applies a predetermined potential to the auxiliary electrode at the time of self-diagnosis, to thereby increase a density of electric force lines generated between the fixed electrode located in a direction of displacing the movable electrode and the movable electrode.

Abstract: A proximity detector circuit that receives a single-ended sensor signal includes (a) an adaptive level control circuit maintaining the single-ended sensor signal within a predetermined voltage range relative a common mode reference signal; and (b) a programmable gain amplifier receiving the single-ended sensor signal and the common mode reference signal as a differential input signal, and providing an output signal derived from amplifying the differential input signal.

Abstract: A capacitive sensor for measuring the clearance between the apex of the vanes of a rotor and the inner surface of an abradable coating covering the inner surface of a turbomachine casing, the clearance measuring capacitive sensor including a first electrode the material of which is abradable so as to get worn upon contacting an apex of a vane, the material of the first electrode having a degree of wear substantially identical to the degree of wear of the material of the abradable coating.

Abstract: A measurement system for measuring an input electrical current (Ics) from a current source (CS) and generating a current measurement signal, comprising a current measuring circuit (70) having a first input terminal (72) connected to the current source and an output terminal (74) for providing the current measurement signal. The current measuring circuit further comprises one or more power supply terminals (75, 76) arranged to receive one or more voltages from a power supply (77a, 77b) for powering the current measuring circuit. The current measuring circuit also comprises a first voltage source (VD) coupled to the one or more power supply terminals, the first voltage source providing a disturbance voltage to the one or more power supply terminals, the disturbance voltage representing a voltage at the first input terminal.

Abstract: A circuit includes a current sensing circuit comprising a current input terminal coupled to an input port, a current output terminal coupled to a transmitted port, and a current sensing output terminal configured to provide a current sensing signal proportional to a current flowing between the current input terminal and the current output terminal. The circuit further includes a voltage sensing circuit having a voltage input terminal coupled to the transmitted port and a voltage sensing output terminal configured to provide a voltage sensing signal proportional to a voltage at the transmitted port. A combining circuit has a first input coupled to the current sensing output terminal, a second input coupled to the voltage sensing output terminal, and a combined output node coupled to an output port.

Abstract: A non-reciprocal radio frequency transceiver front end utilizing multiple time-varying transmission lines (TVTLs) implemented using distributed modulated capacitors (DMC) to exploit time-varying properties of transmission line structures to isolate the transmit and receive signals. The TVTLs are coupled at an input side to an antenna and ground through a first 90 degree coupler, and the outputs of the TVTLs are coupled through a second 90 degree coupler for connection to a receiver and transmit circuit, respectively. The apparatus allows simultaneously operating a transmitter and receiver sharing a single antenna (or single antenna array).

Abstract: Fill level measuring device having a control unit, which contains a high-frequency generator for generating a transmission signal, an amplifier, an amplifier and an evaluation unit, and a spatially remote probe, which contains a measuring impedance, a reference impedance, a first rectifier and a second rectifier, as well as a connecting line between the control unit and the probe, wherein the rectifier detects the voltage of the transmission signal in the probe, and this voltage is transmitted to the control unit as a first DC voltage signal, and the rectifier converts the probe current in the probe into a second DC voltage signal via measuring resistors, and both signals are supplied to the control unit for the purpose of determining the fill level, wherein the rectifiers are thermally coupled to one another.

Abstract: The present invention relates to a measuring device (10) for measuring a resistance of a switching contact (5) of an electrical circuit breaker (1). The measuring device (10) comprises a high-current generating unit (11) for generating a measurement current for the resistance measurement, and a measuring unit (12) for registering a measurement signal at the circuit breaker (1) during the opening or closing of the switching contact (5), and for determining a time-based resistance course of the switching contact (5) during opening or closing, in dependence on the measurement current and the measurement signal.

Abstract: A method and circuit for implementing high current capability Kelvin connections and measuring the resistance of the contacts and connections to verify that the conducting path is capable of carrying the high current without damage or degraded performance. Included as well is the means and circuit for efficiently dividing a high current test stimulus current into 2 paths with low losses and voltage drops.

Abstract: A touch-sensitive device includes a touch panel, a drive unit, a sense unit, and a measurement unit. A touch applied to a node of the panel changes a capacitive coupling between two electrodes (a drive electrode and a sense electrode) of the touch panel. The drive unit delivers a drive signal, which may comprise one or more drive pulses, to the drive electrode. The sense unit couples to the sense electrode, and generates a response signal that that is used to accumulate charge in a charge accumulator to provide an accumulated signal. The accumulated signal is responsive to the capacitive coupling between the electrodes, and is measured to provide an indication of a touch at the node.

Abstract: Due to their exposure to extreme environments, it is expected that parts or all of a solar power system will experience degradation in performance. The degradation may be due to temporary environmental factors, such as cloud cover; damage or localized soiling; a general dirty condition; or ageing of the components. A method is disclosed wherein a remote system may detect degraded performance and determine the cause, thereby enabling a decision as to the appropriate corrective action to be taken, if any.

Abstract: Provided is a low-power direct current detector. The low-power direct current detector includes a main current source circuit generating an ultra-low current, a limitation circuit limiting the current generated by the main current source circuit to lower than a preset current, and a voltage detection circuit biased by the ultra-low current generated by the main current source circuit to detect an input DC voltage.

Abstract: A system and method that allows a consumer to monitor the electrical power usage in a residence is disclosed. The electrical use may be monitored at the service level, the circuit level, or at the group level. The electrical usage is communicated to a power monitoring system using a power line communications network (PLC). The monitored electrical usage can be accessed by both the utility supplying the electricity and by the consumer or owner of the residence.

Abstract: A method of and system for regulating voltage supplied by a local power supply to a remote load includes sensing a low frequency portion of the output voltage at the remote load, locally sensing a high frequency portion of the output voltage produced by the local power supply, and in response, controlling the output of the supply.

Abstract: A remote controller for a television/video recorder having a function of measuring a body fat includes a display section for displaying a measurement of the body fat and a message questioning whether or not a user to be examined carries a specific medical device such as a pacemaker, a reply entry section for entering a reply to the message, and a control section for controlling the action of a body fat meter. The control section directs the display section to display the message prior to the measurement of the body fat. Then, when receiving from the reply entry section a reply indicating that the user carries a pacemaker, the control section inhibits the measurement of the body fat and directs the display section to display a message of the inhibition. When receiving from the reply entry section a reply indicating that the user carries no pacemaker, the control section enables the measurement of the body fat of the user through registering the physical data including the weight and the height of the user.

Abstract: An operating and evaluation circuit of an insect sensor is provided, which has a resistor that is dependent on insect infestation, whereby the circuit during stimulation via a transponder generates a current flow through the resistor, detects a change in the resistor as a change in voltage, and compares it with a predetermined threshold. The circuit includes a transponder-stimulated constant current source, which is connected with the resistor so that a constant voltage drops across the resistor.

Abstract: When measuring body fat through use of a TV remote control unit, the body of a person to be subjected to body fat measurement is brought into contact with current application electrodes and voltage measurement electrodes, which are subjected to application of a sinusoidal waveform signal and have a connection configuration of substantially two-electrode type. When a match has arisen between varying voltages developing between the voltage measurement electrodes a predetermined number of times, the voltage is taken as a result of measurement of bio-impedance.

Abstract: The output current value of a direct-current power source obtained by low-frequency, minute modulation of the input voltage of a switching converter is detected in a circuit having an amplification factor switching function that switches the amplification factor between definite magnitudes synchronizing with the modulation, and by using a signal obtained by demodulating in a discriminator circuit the output of this circuit synchronizing with the modulation to control the switching converter, the power point of the switching converter can be tracked to the maximum power point by following the change in state of the direct current power source.

Abstract: A monitoring circuit interfacing an open collector output circuit with a voltage offset, wherein the voltage offset exhibited between the monitoring circuit and the open collector output circuit prevents direct interfacing with a digital input of an adjacent digital circuit. The monitoring circuit of the present invention includes, a first bipolar junction transistor (BJT) connected to an open collector output circuit having a first ground. The first bipolar junction has a second ground that is different from the first ground. The first and second ground creates an appreciable voltage offset therebetween when the first BJT interfaces with the open collector output circuit. The monitoring circuit also includes a second BJT connected to the first BJT in a loop configuration so that at least one of the first and second BJTs increases base current drive to its respective BJT. The monitoring circuit of the present invention therefore maximizes a turn-on rate of its adjacent digital circuit.

Abstract: A circuit includes an integrator arranged to integrate input signals over a predetermined sample period based on the cycle period of a power source signal. A delay is coupled to the integrator and is responsive to the end of a sample period to delay start of a successive sample period for a predetermined time delay to cancel low frequency noise induced into the circuit during a prior sample period.

Abstract: A device for increasing the sensitivity of a testing instrument in determining the presence of an electronic component, such as a miniature ceramic chip capacitor, at the test station before beginning the test procedure, including a signal booster having an input and an output in operable arrangement for boosting an incoming alternating signal from the testing device by a multiple greater than one, connecting the input of the signal booster between the signal output of the testing device and the station for positioning the component for measuring, and connecting the output of the signal booster between an independent direct current power supply and the test station to boost the signal of the presence testing program by a multiple that brings the measurable signal of the component within the range of sensitivity of the testing instrument.

Abstract: A contact resistance check circuit and method for verifying that a sufficient electrical connection is established between a source and a sense lead of a Kelvin connection. The circuit includes a microprocessor for driving a transformer that is connected to the source/sense probe (i.e., contact resistance) with an input pulse. The input pulse is altered in relation to the magnitude of the contact resistance to produce a check pulse. A comparator is used to compare the check pulse with a threshold voltage and for generating a fault indication signal. A flip flop then stores the fault indication signal so that the fault indication signal may be monitored by the microprocessor.

Abstract: A device in a motor vehicle, with which signals which are generated by a sensor and represent a physical magnitude are transmitted on signal lines. The device includes a voltage divider which is composed of the sensor and at least two impedances which are connected each at one end of the sensor. The signals generated by the sensor are guided, via signal lines connected at its terminals, to a differentiator, by which the usable signal is obtained, and interference signals coupled onto the signal lines are eliminated. Alternatively, the device can also be used for transmission on a signal line pair of any desired potential difference present at an impedance.

Abstract: A contact resistance check circuit and method for verifying that a sufficient electrical connection is established between a source and a sense lead of a Kelvin connection. The circuit includes a microprocessor for driving a transformer that is connected to the source/sense probe (i.e., contact resistance) with an input pulse. The input pulse is altered in relation to the magnitude of the contact resistance to produce a check pulse. A comparator is used to compare the check pulse with a threshold voltage and for generating a fault indication signal. A flip flop then stores the fault indication signal so that the fault indication signal may be monitored by the microprocessor.

Abstract: An apparatus for bootstrapping an amplifier of a capacitive displacement transducer. The apparatus replaces a transformer with two capacitors and two resistors configured to provide biased supply voltages to the positive and negative power supply connections of an amplifier configured as a high impedance unity gain buffer in the transducer. The replacement of the transformer with a pair of standard capacitors and resistors provides for similar performance at a reduced size and cost.

Abstract: A voltage follower is incorporated within a molded electrical connector interface of a position sensor in a way that does not detract from the dimensions or the performance of the finished sensor. The incorporation of the voltage follower into the housing of the variable resistor provides several advantages over the prior art, including: an immunity to sag; substantially reduced sensitivity to noisy contactors; and short lead length and low output impedance, both of which result in reduced interference from external source.

Abstract: A measuring transmitter assembly using the same lines for power input and for output signals and using a single power supply, has a first power input and signal output loop coupled to the power supply, a second power input and signal output loop coupled to the power supply, a first sensor for providing a first input signal in response to the value of a first parameter and a second sensor providing a second input signal in response to the value of a second parameter, and a controller coupled to the first and second sensors. The controller is also coupled to the first and second power input and signal output loops and provides a first output signal on the first power input and signal output loop in response to the first input signal and a second output signal on the second power input and signal output loop. The second output signal may be in response to only the second output signal or it may be in response to the first and second input signals.

Abstract: Apparatus and method for testing lines. The apparatus is particularly useful for testing lines in a switched network, such as might be used to electronically route telephone and computer data lines to various offices in an office building. The apparatus includes an AC test source and a DC measurement device located at a near end switch. A DC transform circuit is located at a far end switch. According to the test method, an AC test signal is injected onto a line under test at the near end. At the far end, the received signal is converted to DC, which is sent to the near end. Line attenuation, and hence fault conditions, are detected by comparing the DC signal to the transmitted AC signal. Techniques to increase the signal to noise ratio of the DC signal are also disclosed.

Abstract: A method for detecting extent of cross-linking of a high impedance polymer material during a pre-cure state, the method including: placing an insulated ground plane adjacent to the polymer material and substantially parallel to a sensor; applying a test signal through a sensor to the material and through a reference resistance; determining a voltage difference between the test signal applied to the material and the reference resistance as the reference voltage; and correlating the voltage difference as a relative indicator of the extent of cross-linking which has occurred within the polymer material. Also disclosed is a device for implementing the subject method.

Abstract: A time varying excitation current (413) is provided to one side of a capacitive sensor (417), and two signal paths (420,430) are provided between the other side of the capacitive sensor (417) and signal conditioning circuitry (412), each signal path differing from the other according to its polarity. The signal paths conduct monopolar signals from the capacitive sensor the magnitude of which are directly related to the capacitance of the sensor, and bi-polar signals the magnitude of which are directly related to the stray capacitance in the signal lines. The combined monopolar and bi-polar signal currents on each signal line are converted into voltage signals (422,433), and the voltage signals are thereafter differenced (460) to provide a null bi-polar output while providing a constant monopolar voltage level the magnitude of which is directly related to the probe capacitor current.

Abstract: A sensor system is disclosed for the contactless measuring of the distance between a sensor body and an object. The sensor body contains an identification resistor, the resistance value of which can be interrogated by a control unit which is connected to the sensor body and which is located outside the sensor body. The interrogation makes it possible to determine whether the electrical connection between the control unit and the sensor body exists or is interrupted. If it is interrupted, this can be detected by the control unit in an unambiguous manner due to the missing connection to the identification resistor, and the control unit can generate an alarm signal in order to avoid faulty positioning of the sensor body relative to the object.

Abstract: An impedance meter is not adversely affected by errors originating from changes in characteristics of measurement cables under measurement conditions such as in an environmental test wherein an element to be measured is remote and high and wide measurement frequencies are used. The voltage and the current of an element to be measured are measured to obtain its impedance and the like. A circuit configuration is provided wherein a cable for supplying a measurement signal to the element to be measured and for detecting the current flowing through the element to be measured is a triaxial cable and a cable for detecting the voltage is a coaxial cable, and wherein impedance matching is performed at the ends of the triaxial cable and the coaxial cable on the side of a measuring device and a balun is provided to float an ammeter on a coaxial cable connecting the ammeter-side end of the triaxial cable to the ammeter.

Abstract: A heater control device for an air-fuel ratio sensor which comprises: an air-fuel ratio sensor comprising a sensor element which detects an air-fuel ratio state of exhaust gas of an engine, and a heater which heats the sensor elements; a heater current flow control means for controlling a value of a resistance of the heater to be a target resistance value; a harness having a couple of couplers at both ends thereof which connects between the air-fuel ratio sensor and the heater current flow control means; and a current detecting resistance which is incorporated in the coupler on the air-fuel ratio sensor side, or provided adjacent to said coupler on the air-fuel ratio sensor side, and which is connected to the heater in series and detects current of the heater.

Abstract: A probe developing an admittance with a material whose condition is to be continuously measured is capacitively coupled with a variable frequency oscillator, preferably one having a digital output stage, for generating a variable frequency signal having a period varying with the admittance developed at the probe. Both the oscillator input and output are capacitively coupled to the probe. In a preferred embodiment, a set point circuit including a plurality of resistors coupled in parallel with the oscillator output and a plurality of switches coupled in parallel with the probe conductor and each with a different one of the resistor, provides easy circuit adjustment for use of the system with a variety of materials. A preferred digital circuit employing a pair of flip flops, fixed timer and one shot generate a fixed period variable duration duty cycle digital voltage level signal for transmission, if desired, or for conversion into a variable current signal.

Abstract: A heater control device for an air-fuel ratio sensor which comprises: an air-fuel ratio sensor comprising a sensor element which detects an air-fuel ratio state of exhaust gas of an engine, and a heater which heats the sensor elements; a heater current flow control means for controlling a value of a resistance of the heater to be a target resistance value; a harness having a couple of couplers at both ends thereof which connects between the air-fuel ratio sensor and the heater current flow control means; and a current detecting resistance which is incorporated in the coupler on the air-fuel ratio sensor side, or provided adjacent to said coupler on the air-fuel ratio sensor side, and which is connected to the heater in series and detects current of the heater.

Abstract: Automatic device for measuring the noise level of electronic components. This device comprises selection means (20) to which are connected the components and which are able to select one of these components, measuring means (28) able to determine the noise of the selected component, said measuring means incorporating means (32,34) for biasing the selected component and for processing signals supplied by the thus biased selected component and also incorporating analysis means (36) determining the noise from signals supplied by the processing means, as well as means (10) for controlling the selection means (20) and measuring means (28), said control means (10) being electrically decoupled from the selection means (20) and the biasing and processing means (32,24). Application to the sorting of electronic components following their manufacture.

Abstract: A signal detector includes a signal input section, a detector, and a converter. The signal input section inputs a high frequency signal to be measured. The detector detects the high frequency signal to be measured input by the signal input section. The converter amplifies the output from the detector and includes a variable gain preamplifier which has a first gain higher than a linear gain when the detecting output is smaller than a predetermined value and a second gain lower than the linear gain when the detecting output is larger than the predetermined value. A cable line transmits an output from the variable gain preamplifier of the converter of the signal detector. A measuring equipment body includes a decoder and an analyzer.

Abstract: A probe developing an admittance with a material whose condition is to be continuously measured is capacitively coupled with a variable frequency oscillator, preferably one having a digital output stage, for generating a variable frequency signal having a period varying with the admittance developed at the probe. Both the oscillator input and output are capacitively coupled to the probe. In a preferred embodiment, a set point circuit including a plurality of resistors coupled in parallel with the oscillator output and a plurality of switches coupled in parallel with the probe conductor and each with a different one of the resistor, provides easy circuit adjustment for use of the system with a variety of materials. A preferred digital circuit employing a pair of flip flops, fixed timer and one shot generate a fixed period variable duration duty cycle digital voltage level signal for transmission, if desired, or for conversion into a variable current signal.

Abstract: The device comprises: a high frequency alternating voltage generator the output of which is connected to a sensor probe 5 which is to be applied to a substrate to be measured, an amplifier the input of which is connected to the sensor probe, and a detector arranged to furnish a D.C. voltage signal based on the output from amplifier. The generator, the amplifier and the detector are located inside a metal envelope enclosure. An electromagnetic radiation shield is disposed inside the envelope to separate the amplifier and the detector from the high frequency generator. In operation, voltage output from the detector is indicative of the electrical impedance of the substrate as sensed at the probe. In the preferred application, the substrate is skin and the measured electrical impedance is indicative of the water content of the skin.

Abstract: A probe developing an admittance with a material whose condition is to be continuously measured is capacitively coupled with a variable frequency oscillator, preferably one having a digital output stage, for generating a variable frequency signal having a period varying with the admittance developed at the probe. Both the oscillator input and output are capacitively coupled to the probe. In a preferred embodiment, a set point circuit including a plurality of resistors coupled in parallel with the oscillator output and a plurality of switches coupled in parallel with the probe conductor and each with a different one of the resistor, provides easy circuit adjustment for use of the system with a variety of materials. A preferred digital circuit employing a pair of flip flops, fixed timer and one shot generate a fixed period variable duration duty cycle digital voltage level signal for transmission, if desired, or for conversion into a variable current signal.

Abstract: A measurement system for measuring an input electrical current (Ics) from a current source (CS) and generating a current measurement signal, comprising a current measuring circuit (70) having a first input terminal (72) connected to the current source and an output terminal (74) for providing the current measurement signal. The current measuring circuit further comprises one or more power supply terminals (75, 76) arranged to receive one or more voltages from a power supply (77a, 77b) for powering the current measuring circuit. The current measuring circuit also comprises a first voltage source (VD) coupled to the one or more power supply terminals, the first voltage source providing a disturbance voltage to the one or more power supply terminals, the disturbance voltage representing a voltage at the first input terminal.