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 solenoid actuation detection device for detecting actuation of an armature of a solenoid includes a sensor for sensing electric current flowing through a solenoid, a peak detector for receiving the sensing signal and for creating a peak signal from the sensing signal, and a comparator for comparing the two signals to determine when an armature of the solenoid was actuated.

Abstract: A sample apparatus includes a sampling valve having a sample inlet through which a sample such as urine is introduced from the outside of the sampling valve to the inside thereof; a sample outlet through which the sample is sent from the inside of the sampling valve to the outside thereof; and a sampling passage for setting apart a predetermined amount of the sample between the sample inlet and sample outlet. It further includes a first electrode section located close to the sample inlet so that the sample can come into contact with the first electrode section, a second electrode section located close to the sample outlet so that the sample can come into contact with the second electrode section, and a sensor circuit for measuring the impedance between the first and second electrode sections and for using the measured impedance to determine whether or not the sampling passage contains a predetermined amount of the sample.

Abstract: A method and system for measuring programmed antifuse resistance in an FPGA without disturbing the antifuse resistance. The method includes estimating a plurality of subparts of the programming path connecting low and high programming voltage sources on the FPGA device, measuring the path as a whole, and subtracting the sum total of the subparts from the whole path measurement, thereby deriving the antifuse resistance. If the derived antifuse resistance is higher than desired, programming and measurement may be repeated to ensure device longevity and accurate timing for implemented designs.

Abstract: The position of a break in at least one of a pair of rails in an electrically isolated rail segment of a railroad is carried out by measuring current across the ballast between the rails of the segment from one end of the segment when one of the rails in the segment is not broken and subsequently when the rail is broken. A position of the break can be calculated as a function of the ballast current. A linear approximation using the ratio of the ballast current when the rail is broken to the ballast current when the rail is not broken multiplied by the distance of the rail segment from the one end gives a satisfactory approximation of the location of the rail break.

Abstract: Measuring apparatus includes a first element having its impedance dependant on the state of its surroundings and a second element having a variable impedance connected to the first element. A voltage at the connection point between the first and second elements is converted into a digital value and the impedance of the second element is set based on the converted digital value. The surrounding state (e.g., humidity) is determined based on the converted digital value.

Abstract: An in-circuit ohmmeter is provided, including a pair of input terminals connectable to a resistance of an unknown value. A pair of current generators are connected electrically in series for generating an electrical current to be passed through the unknown resistance to develop a differential voltage across the input terminals, and a circuit is provided for determining the amount of the electrical current passed through the unknown resistance. A semiconductor switch switches the pair of current generators on and off. A current generator protection circuit comprising a plurality of diodes is connected across the input terminals. A differential amplifier circuit receives and amplifies the differential voltage so that a value of the unknown resistance may be calculated based on the differential voltage and the determined amount of electrical current passed through the resistance. An inverter circuit is disposed intermediate the input terminals and the differential amplifier circuit.

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: A method and apparatus for measuring the electrical resistance of a circuit energized with AC power. The invention imposes a known DC current in the circuit under test and senses a resulting DC voltage drop that corresponds to the resistance of the circuit. The invention senses AC overvoltage conditions in the circuit under test and electrically isolates the measuring circuit from the circuit under test.

Abstract: A method for detecting extent of cross-linking of a high impedance polymer material during a pre-cure stage, the method comprising the steps of:a) applying a test signal through a sensor to the polymer material in the pre-cure stage to determine a level of impedance and corresponding sample voltage representative of a degree of cross-linking within the material;b) applying the same test signal through the sensor to a reference material having a fixed resistance to determine a reference voltage;c) determining a voltage difference between the test signal applied to the polymer at pre-cure stage and the test signal applied to the reference material as the reference voltage;d) correlating the voltage difference as a relative indicator of the extent of cross-linking which has occurred within the polymer material, based on comparison of magnitude of the voltage difference with respect to a comparable potential range of impedance for the polymer material from its lower impedance stage at minimal cross-linking to its

Abstract: A method for detecting extent of cross-linking of a high impedance material during a shelf life, slow state transition or during use, the method including: applying a test signal through a sensor to the material and through a reference material; determining a voltage difference between the test signal applied to the material and the reference material as the reference voltage; and correlating the voltage difference as a relative indicator of the extent of chemical change which has occurred within the material. Also disclosed is a device for implementing the subject method.

Abstract: A method and apparatus for determining the quality of a colloidal suspension. According to the method of the present invention, an oscillating input electrical signal is applied simultaneously to a sample of the colloidal suspension to be tested and to a reference resistor. The reference resistor has a predetermined impedance value that is substantially identical to the colloidal suspension. The input signal causes charge particles and molecules within both substances to move, thereby, giving rise to electrical currents. Thus, a test current is extracted from the colloidal suspension and a reference current is extracted from the reference resistor. Thereafter, a differential output current is derived by subtracting the reference current from the test current. The average value of the differential output current and the peak value of the test current are measured. Based on the peak value of the test current and the average value of the differential output, the quality of the colloidal suspension is determined.

Abstract: In a voltage drop detecting circuit, when voltage Vcc being monitored is at a steady-state value, reference voltage B is classified by divided voltages Va to Vc from detection voltage generation circuit group for classification of reference voltage. In accordance with the result of that classification, one of the divided voltages Va to Vc from detection voltage generation circuit group for detection of a drop in the voltage being monitored is selected as detection voltage A. Since the resistance ratio can be expressed fairly correctly in ICs, the circuit structure of the voltage drop detecting circuit is capable of reducing the apparent range of variation of reference voltage B, whereby the precision of detection is improved.

Abstract: A resistance measuring circuit (10) generates a predetermined reference voltage and impresses that reference voltage across a squib detonation device (12). The resulting current flowing through the squib is mirrored by a current mirror (42,52,54) for providing multiple mirrored currents. The mirrored currents are compared to known current sources (58,60). The output signals go high or low depending on whether the mirrored currents are greater than or less than the fixed current sources. The output signals provide an indication as to whether the measured squib resistance is within a specified resistance range. The current sources may be precisely matched to maintain high accuracy in measuring the resistance.

Abstract: Electronic circuitry for simulating the resistance characteristics of a variable resistance temperature sensing element includes a multiplier that multiplies the difference between a reference voltage and a desired value of a control voltage times the voltage across a precision resistor at the output of the circuitry. The multiplier product output signal is integrated and a voltage value of the integrator output controls the gate terminal of a field effect transistor. The drain and source terminals of the transistor are connected in series with the precision resistor. The combination of the current through the precision resistor and the transistor (or the voltage across the precision resistor), together with the voltage value of the control signal, controls the voltage input value to the integrator, which, in turn, controls the resulting resistance across the output terminals of the transistor.

Abstract: A constant current loop measuring system measures a property including the temperature of a sensor responsive to an external condition being measured. The measuring system includes thermocouple conductors connected to the sensor, sensing first and second induced voltages responsive to the external condition. In addition, the measuring system includes a current generator and reversor generating a constant current, and supplying the constant current to the thermocouple conductors in forward and reverse directions generating first and second measured voltages, and a determining unit receiving the first and second measured voltages from the current generator and reversor, and determining the temperature of the sensor responsive to the first and second measured voltages.

Abstract: An IC element testing device includes a test pattern generating unit for generating test patterns, a power supply unit for generating a power supply voltage, a superposed voltage generating unit for generating a superposed voltage, and a superposing unit for superposing the superposed voltage on the power supply voltage and for outputting a superposed power supply voltage to an IC element to which the test patterns generated by the test pattern generating unit are applied.

Abstract: Disclosed is an apparatus for detecting a resistance value of a resistor sensor through three signal lines with high detection accuracy. In the apparatus, a reference resistance element is inserted in a current path of a reference current, first and second voltages across the ground and first and second signal lines are respectively held in first and second holding portions and a third voltage across the terminals of a reference resistance element is held in a third holding portion. The first and second voltages held in the first and second holding portions are output simultaneously and the third voltage held in the third holding portion is output at a timing different from the timing when the first and second voltages are output. A differential amplifier detects the third voltage and a differential voltage.

Abstract: An inactive state termination tester for determining the number of terminators connected to a bus when the bus is inactive. The termination tester monitors the bus for determining when it is inactive. During the periods of bus inactivity, the termination tester senses the bus to determine the number of terminators connected to the bus. The termination tester then displays how many terminators were detected.

Abstract: A method and apparatus for testing circuit boards uses a pair of probes to contact the various nodes on the circuit board. A single one of the pair of probes may be used to deposit a charge at a being tested net and checking for the presence of a charge at subsequent nets to determine whether a short condition exists. Moreover, the pair of probes is used to contact two nodes of a network being tested to measure the resistance within the network being tested; the measured resistance being compared to a nominal resistance, to determine whether an open condition exists. In addition, the pair of probes may be used to measure the resistance between networks in order to verify or determine whether a short condition exists between networks.

Abstract: A method for detecting extent of cross-linking of a high impedance polymer material during a pre-cure state, the method including: 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 device for detecting attempts at fraud by connection of an electric feed line (13) to an apparatus for reading and writing on a chip card (3) essentially comprises a resonance unit (6) coupled to a contacting element (2) of the apparatus, and a measuring device (7). In the resonance unit (6) a generator (4) which is coupled to a resonator (1) by way of an impedance converter (5) generates a standing wave. The feed line (13) disturbs the properties of the resonator (1), that being detected by the measuring device (7) and evaluated.

Abstract: A constant current loop measuring system is provided for measuring a characteristic of an environment. The system comprises a first impedance positionable in the environment, a second impedance coupled in series with said first impedance and a parasitic impedance electrically coupled to the first and second impedances. A current generating device, electrically coupled in series with the first and second impedances, provides a constant current through the first and second impedances to produce first and second voltages across the first and second impedances, respectively, and a parasitic voltage across the parasitic impedance. A high impedance voltage measuring device measures a voltage difference between the first and second voltages independent of the parasitic voltage to produce a characteristic voltage representative of the characteristic of the environment.

Abstract: A measuring circuit with a biosensor utilizing ion sensitive field effect transistors having a simplified structure and is advantageous to integration. The measuring circuit comprises two ion sensitive FET input devices composed of an enzyme FET having an enzyme sensitive membrane on the gate and a reference FET, and a differential amplifier for amplifying the outputs of the enzyme FET and the reference FET. The drift phenomena of the ISFETs due to the use of a non-stable quasi-reference electrode as well as the temperature dependence thereof can be eliminated by the differential amplifier consisting of MOSFETs having the same channel as the ISFETs. The ISFET biosensor and the measuring circuit can be integrated into one chip.

Abstract: A method and apparatus for determining the quality of a colloidal suspension. According to the method of the present invention, an oscillating input electrical signal is applied simultaneously to a sample of the colloidal suspension to be tested and to a reference solution. The reference solution is substantially identical to the colloidal suspension except that the colloidal particles have been removed. The input signal causes charge particles and molecules within both substances to move, thereby, giving rise to electrical currents. Thus, a test current is extracted from the colloidal suspension and a reference current is extracted from the reference solution. Thereafter, a differential output current is derived by substracting the reference current from the test current. The peak-to-peak magnitude of the differential output current is measured, and the phase of the output current is compared to the phase of the input signal to determine the difference in phase between the two signals.

Abstract: A circuit for the detection of a fuse with oxide vertical fusing has another fuse that is of the same type but cannot be blown and, in parallel with each of the fuses, a voltage reference circuit. The output of each of the voltage reference circuits is an input of a differential comparator. This differential comparator is preferably provided with a voltage reference circuit that is independent of the supply voltage Vcc.

Abstract: A portable resistance tester comprises a pair of regulator circuits used to drive a bridge circuit and a detector circuit when measuring the resistance values of "in-circuit" test nodes. The tester produces an audible signal when the resistance of a measured test node falls within, or without, a predetermined resistance range.

Abstract: An apparatus and method employing a liquid level detection conductance probe mounted in a container to sense resistive differences between the probe and container depending upon the presence or absence of liquid therebetween. A sensing circuit senses probe signal variations and stores a probe signal. A comparator compares the stored probe signal to current probe signals and switches means connected to the comparator depending upon the presence or absence of liquid between the probe and container. The sensing circuit has sufficient sensitivity to differentiate between liquid between the probe and container and foam or scale deposits therebetween.

Abstract: An apparatus and method for determining both the breakdown voltage and the conductivity of a particulate material, such as a developer material, is provided. In a preferred embodiment, the apparatus for determining breakdown voltage comprises a breakdown cell for storing a preselected quantity of the particulate material and a voltage breakdown ("VB") autometer, the VB autometer being adapted to apply a first voltage across at least portions of the preselected quantity of the particulate material. The VB autometer is capable of progressively varying the magnitude of the first voltage. A measuring circuit, for measuring a second voltage, is coupled to the voltage breakdown cell. When the second voltage substantially equals a preselected reference voltage, the first voltage substantially equals the breakdown voltage of the particulate material.

Abstract: A checking circuit for checking the normal operation of a sensor comprising a sensor, a controller for switching the checking circuit operation between an open check mode and a sensing mode. The circuit for effecting the open check mode is responsive to a first logical output signal from the controller. The circuit for effecting the sensing mode is responsive to a second logical output signal from the controller, however, the sensing is only accomplished after successful completion of the open check mode.

Abstract: An apparatus for measuring differential impedances which incorporates a CMOS timer in place of the sine wave generator in a typical AC bridge configuration. A toroidal signal transformer having its primary and secondary windings tightly twisted together and wound around the core lessens temperature drift characteristics. The differential bipolar current signal provided by the secondary winding is passed through an AC to DC converter which is switched by a field effect transistor, thereby eliminating the need for prior art inverter comparator circuits. Finally, by use of a bandpass filter after the signal transformer and by insertion of a capacitor before the AC to DC converter, the need for the active filter stage used in the prior art is eliminated.

Abstract: A device for monitoring the grounding characteristics of both an electrically dissipative work surface and a conductive wrist strap having a grounding tether. The device includes a mat monitor and a strap monitor. The mat monitor checks the resistance of the mat ground path and alerts the user if this resistance exceeds a predetermined resistance. The strap monitor checks the resistance of the wrist strap and tether ground path, and employs a timer to send electrical pulses to the wrist strap rather than having a constant voltage output to the strap. The strap monitor establishes a resistance window for the strap ground path, and alerts the user if the strap ground path resistance falls outside of the resistance window.

Abstract: For the measurement of gas, vapor, or aerosol fractions of a measured gas, the fraction to be determined is absorbed in a reaction solution, and a change of resistance from a reaction between the fraction and the reaction solution is determined as the measured variable by an ohmmeter, using electrodes in the reaction solution. The measured gas entering a test container through a sealing unit tight to the reaction solution and passing the medium to be determined, is improved with regard to all-purpose use and convenient measurement. This is done pursuant to the invention by placing the reaction solution in a disposable test container that can be inserted or connected interchangeably to the measuring device which has electrodes. The test container is sealed, at least at one end, with a sealing unit that is permeable to the medium to be determined and impermeable to the reaction solution.

Abstract: A circuit for sensing the state of a potentiometer includes a capacitor that is connected to the potentiometer wiper and that is successively charged by applying a voltage to each end of the potentiometer resistive element. The capacitor is discharged between successive chargings. The times needed to charge the capacitor to a predetermined voltage in each case are used to determine the position of the wiper along the resistive element. The circuit can be connected to a plurality of potentiometers, any one of which can be selected and the wiper position determined. A similar circuit can determine the state of an inductive or capacitive voltage divider.

Abstract: A four terminal ohmmeter apparatus includes circuitry for blanking the meter read-out in the event one or more connections to a device or structure under test have been improperly made. The voltage drop between current terminals is determined and compared with a threshold value. The voltage drop between potential terminals or between potential and current terminals, as caused by a separate a.c. source, is also determined and compared with a standard. Individual indicators inform the operator of the validity of each connection in order that corrective action can be taken if necessary. Voltage inputs are also utilized for ascertaining whether a correct meter range is being used and for changing the range if it is improper.