Abstract: A circuit for detecting a particular frequency out of a signal coming in over a telephone line or similar communication path. The circuit has not only a band-pass filter having a frequency band to be detected but also band-pass filters covering frequency bands adjoining. A particular frequency is detected on the basis of the results of comparison of the output levels of the band-pass filters and reference levels.

Abstract: A contact hazard meter used to measure electromagnetic field induced currents which would flow through a human body to ground upon physical contact with an item carrying such field induced currents includes a conductive contact, a human equivalent circuit coupled to the conductive contact and an electronic circuit coupled to the human equivalent circuit for measuring and displaying a measurement of current flowing from the item and through the human equivalent circuit when the conductive contact is placed in physical contact with the item carrying the field induced currents. The human equivalent circuit approximates the impedance of the human body at varying frequencies. The contact hazard meter has a plurality of range settings, one setting providing the resultant current as a percentage of a safety guideline maximum permissible exposure value.

Abstract: A controller of a card radio modem connectable to a data terminal measures two kinds of a battery voltage under a different load condition of the card radio modem. The controller determines the kind of battery and detects the remaining time of accuracy, based on the kind of the battery. In addition, the controller calculates an available capacity of a file data to be transmitted and received during the remaining time. When the available capacity is smaller than a capacity which is necessary to transmit and receive, the controller generates an alarm to inform an operator. The controller displays the available capacity or remaining time on a display.

Abstract: A noise measurement test system 10' for making phase noise and amplitude noise measurements of microwave signals derived from a continuous wave RF source. The system 10' comprises an RF input for receiving an applied RF noise signal and an RF coupler 11 coupled to the RF input for splitting the applied RF noise signal into first and second paths 18a, 18b. A mixer 15 that comprises a synchronous phase detector 15 is coupled to receive signals from the first and second paths 18a, 18b, respectively, and which outputs demodulated phase noise. The first path 18a comprises a variable attenuator 14 and a variable phase shifter 13 coupled between the coupler 11 and the first input of the mixer 15 for providing a reference signal input to the synchronous detector 15. The second path 18b comprises a delay line and an adjustable RF carrier nulling circuit 30 coupled between the coupler 11 and the mixer 15.

Abstract: Dynamic gain adjustment in hydraulic piston position sensing that continuously accommodates for changes in signal level is provided by attenuating the gain of the sensing system through a comparison of a measured value with a stored value at each piston position.

Abstract: The invention provides method and apparatus for identifying the faulted phases on the occurrence of a single phase fault simultaneously on both circuits of a double circuit electric power transmission line using measurements taken at one end only of the line. Using measurements of voltage and current at the one end of the line and a knowledge of various parameters of the line, a signal representative of the travelling wave arriving at the one end of the line in consequence of the faults is derived. This derived signal is used to deduce the values of the components of the derived signal attributable to the different faults for each of a number of assumptions as to which phases are faulted. The deduced values for the different assumptions are then used to determine which assumption is most likely to be correct.

Abstract: Triboelectricity, that is the electrostatic charging of materials by rubbing them against one another, is used to identify particular plastics materials which produce a characteristic charge polarity when rubbed against another known material. An apparatus (24) for carrying out this identification mounts different reference materials (30, 32, 34) so that they can be rubbed against the material (44) to be identified to create electrostatic charges which are then processed by a logic circuit to identify the nature of the sample.

Abstract: A standard resistor having a known resistance value is connected to one transistor in a drive IC. The drive IC has a plurality of transistors each controlling on/off switching of a heating element. The saturation voltage of each transistor is generally the same. One of a plurality of transistors is turned on, and a discharge time required for a capacitor to discharge via a standard resistor or via each heating element and lower its voltage to a predetermined voltage is measured. The resistance value of each heating element is determined from a ratio of a discharge time via each heating element to a discharge time via the standard resistor and the resistance value of the standard resistor. A difference between the standard resistance value and a resistance value of each heating element generates a bias heat energy error during bias heating and an image heat energy error during image heating.

Abstract: Seepage of water and other impurities into hermetically sealed on plastic encapsulated modules leads to eventual device failure, as conductor material corrodes and opens, or electromigrates to establish conductive trails across a substrate, shorting the conductors. To forewarn of such failure, a sensing device defined as a separate chip is packaged in the same module with the circuit to be checked, with pinouts that can be tested with a circuit that is usually external. The sensor makes use of the moisture-induced migratory behavior that causes the problem, using a highly migratory metal or alloy to define paired electrodes spaced as closely as 2 micrometers apart. The metal of the electrodes undergoes rapid ionization and migration in the presence of trace amounts of moisture, dissolved ionic contaminants, and a small potential difference across the electrodes.

Abstract: A connector formed with a first portion on the connector positioned differently according to a kind of the connector. The first portion is, for example, the forward end of a terminal or a cutout formed on the housing of the connector. At least one multicontact switch pin is fixedly arranged on a carriage base in a direction such that the probe pin of the multicontact pin extends towards the first portion. The switch pin has at least two contacts and a probe pin projecting outwardly of the multicontact switch pin. Each of the contacts is connected to a corresponding test circuit. The probe pin is adapted to move into and/or out of contact with the contacts when the probe pin is pushed inwardly into the multicontact switch pin. The carriage base is moved by a predetermined distance towards the connector to allow the probe pin to engage the first portion so that the probe pin moves into and/or out of contact with said contacts.

Abstract: A device for measuring circuit breaker wear by integrating the square of the current to be interrupted, said circuit breaker including a control that is actuated by a trip coil. The device includes a timing delay circuit that is actuated by a signal corresponding to a change in the driven or non-drive state of the trip coil, the timing delay circuit causing integration to begin after time has elapsed that is equal to the mechanical delay of the circuit breaker, which mechanical delay is a previously-measured data item. The device further includes a circuit that delivers a signal proportional to the current carried by the circuit breaker, a circuit that squares the signal, and that applies said square to the integrator, said integration being performed for a given length of time that is longer than the maximum arcing time of the circuit breaker, which maximum arcing time is likewise a previously measured data item, the result of the integration being applied to a summing circuit.

Abstract: The Integrated Grid Particle Impact Detector (IGMID) uses an integrated semiconductor grid system to detect hypervelocity article impacts on space vehicles and to indirectly determine article diameter of impacting particles. The detector consists of multiple sets of parallel aluminum electrical paths. The first set of parallel aluminum electrical paths is located on the top surface of the detector. The second and subsequent sets are located some distance below the top surface of the detector with the paths being perpendicular and/or parallel to the first set of paths. When a particle traveling at hypervelocity impacts the detector one or more detector paths will be vaporized, resulting in an electrically open path. This in turn will result in the output of the n-type and p-type CMOS circuits to change state. Using standard CMOS VLSI design techniques, specific electrically open grid paths can be identified.

Abstract: An apparatus, and a corresponding method, for stress testing both wire bond-type semiconductor chips and C4-type semiconductor chips is disclosed.

Abstract: Apparatus for inspecting non-round annular containers includes elongated capacitive sensors, cooperating oscillators, which convert the sensor signal to a voltage corresponding thereto, and an electronic processor which receives the voltage and determines thickness. A displaceable electromechanical member is operatively associated with the sensor and emits an electrical signal corresponding to the degree of displacement of the sensor by a container being inspected. The electronic processor corrects the thickness determination by an adjustment of container diameter at the specific location where thickness is being monitored in order to compensate for container diameter variations due to the non-round characteristic of the container. In a preferred embodiment, linkage members secured to the rear of the sensor at a plurality of locations cooperate with a single displaceable element which converts the mechanical displacement of the sensor into a corresponding electrical signal.

Abstract: A device for checking the weights of individual capsules in a stream of capsules by passing the stream of capsules past a capacitance sensor which measures the capacitance of each capsule as representative of the capsule weight, and passing the stream of capsules past a velocity sensor which measures the velocity of each capsule as representative of the capsule weight. The measured capacitance and measured velocity values are each compared against preset ranges of values, and a capsule is mechanically deflected from the moving stream if the comparison shows either measured value to be outside the respective preset range of values.

Abstract: A circuit layout for measuring ion concentrations in solutions using ion-sitive field effect transistors is provided. The circuit layout makes it possible to represent the threshold voltage difference of two ISFETs directly and independently of technological tolerances, operationally caused parameter fluctuations, and ambient influences. The circuit layout includes two measuring or test amplifiers, with in each case two differently or identically sensitive ISFETs and two identical FETs. The ISFETs and FETs are connected in such a manner that at the output of the first measuring amplifier occurs the difference of the mean value of the two ISFET threshold voltages and the FET threshold voltage and at the output of the second measuring amplifier occurs the difference of the two ISFET threshold voltages. The output of the first amplifier is connected to the common reference electrode of the four ISFETs.

Abstract: A capacitance measuring device comprises a MOS transistor having a source, drain, and gate; a first capacitor C.sub.1 connected between said gate and said drain so that charge is coupled from said drain onto said gate; and a second capacitor C.sub.2 for connection to a source of gate voltage V.sub.G and connected to said gate. One of the first and second capacitors has a known capacitance and the other has an unknown capacitance. A DC voltage is supplied between the source and drain to cause a saturation current to flow therebetween. The ratio .delta.V.sub.G /.delta.V.sub.d for the saturation current, where V.sub.G is the applied gate voltage, and V.sub.d is the drain voltage is determined and the unknown capacitance is derived from the relationship C.sub.1 /C.sub.2 =-.delta.V.sub.G /.delta.V.sub.d.

Abstract: A converter and digital channel selector device is provided which is interconnected between a source measurement unit having a plurality of output terminal connectors and a probe station having a plurality of input probe terminal connectors. The channel selector device is used to selectively connect each one of the plurality of output terminals of the source measurement unit to corresponding one of the plurality of input probe terminal connectors, respectively. The channel selector device includes a converter for generating a plurality of digital control signals and a digital channel select logic circuit which is responsive to the digital control signals for selectively connecting respective ones of a plurality of its input channel connectors connected to the plurality of output terminal connectors to any one of a plurality of its output channel connectors connected to the plurality of input probe terminal connectors.

Abstract: A device for injecting current at radio frequency into electric wiring, comprises a guiding structure (10) of an electrically conductive material consisting of a tapered shell (12) wherein a central vertical wall (20) is suspended determining two half-spaces (S, D) within the shell (12). At the tapered end, the shell (12) and the central vertical wall (20) are respectively connected to the braiding and the central wire of a coaxial cable (17) supplying radio frequency electric current. At the end opposite to said tapered end, a wiring (19) is disposed through the structure (10) perpendicular to the vertical central wall (20) and rests on a base (11) of dissipating material. In one of the two half-spaces, the wiring (19) is protected by a shield (23) integral with the shell (12).

Abstract: Surface potential is detected with high precision by removing induction noise generated by a drive circuit and transmitted to a detection electrode. Induction noise imparted by a drive circuit to an A.C. voltage signal is cancelled out by supplying an output of a pre-amplifier for amplifying the A.C. voltage signal derived from a detection electrode and an output of the drive circuit for applying a drive signal to a chopper portion to a differential amplifier and differentially amplifying them. Particularly, an attenuator for making a level of the amplified A.C. voltage signal substantially coincident with a level of a signal from the drive circuit and an inverter/amplifier for making phase deviation coincident are provided in an output portion of the pre-amplifier circuit.