Abstract: A system for determining electrical characteristics of an electric load can comprise a signal modulation circuit that can include a first integral controller configured to control AC reference voltage based on a requested maximum AC current and an estimated maximum AC current, a second integral controller configured to control DC reference voltage based on a requested DC current and an estimated DC current, a signal demodulation circuit including an AC current estimation circuit configured to generate the estimated maximum AC current for the signal modulation circuit, a DC current estimation circuit configured to generate the estimated DC current for the signal modulation circuit, and a resistance and inductance (RL) estimation circuit configured to determine inductance of the electric load based on the estimated maximum AC current and phase shift, wherein the estimated maximum AC current is a value lower than a DC offset current value.

Abstract: A circuit of decreasing an electromagnetic interference of PWM pulse modulation signal has: a load detecting circuit used to output a mode detection signal to a control circuit according to a current generated by a load when the load connected to the load detecting circuit is detected; the control circuit connected to the load detecting circuit and outputting a voltage control signal to a resistance-adjustment circuit according to the mode detection signal; the resistance-adjustment circuit connected to the control circuit, adjusting a resistance of a driving resistor of the resistance-adjustment circuit and further adjusting a driving frequency of a pulse generating circuit; and the pulse generating circuit connected to the resistance-adjustment circuit and outputting a PWM pulse modulation signal according to the adjusted driving frequency. Under the heavy loading mode, the driving frequency of the PWM pulse modulation signal is adjusted so the electromagnetic interference is decreased effectively.

Abstract: An information displaying device is provided with a display portion that displays an image based on display information and a predetermined driving voltage, a CPU that sets a boost target value of the driving voltage of the display portion, a voltage divider resistance circuit that divides a power supply voltage to generate output candidates of the driving voltage having plural output values, a selector that selects the output values, successively, based on tap selection signals from a lower rank of the output candidates of the driving voltages in the voltage divider resistance circuit to a higher rank thereof and boosts the driving voltage and a slow starter that compares an output value of the driving voltage boosted by the selector with the boost target value set by the CPU, determines whether or not the output value of the driving voltage reaches the boost target value, and drives the display portion at the driving voltage reaching the boost target value based on a determination result thereof.

Abstract: Measurement devices, systems, and methods to measure a high field conductivity of a fluid are provided herein. The measurement device includes a fluid cell, a pair of electrodes, a voltage switch, and a measurement unit. The fluid cell is on an inclined plane to receive the fluid. The pair of electrodes are connected to the fluid cell. The pair of electrodes are spaced apart from one another to receive the fluid therebetween and positioned parallel to one another to pass an electrical current therethrough. The power unit provides a high voltage power supply to one electrode of the pair of electrodes. The measurement unit measures the electrical current that passes between the pair of electrodes through the fluid.

Abstract: A resistance-measuring circuit includes a controller for outputting a PWM signal and further for adjusting the duty cycle of the PWM signal, and a sampling circuit for processing the PWM signal and transmitting the processed PWM signal to the sensor. The sampling circuit samples the signal outputted from the sensor to generate a sampled signal with the voltage thereof changing according to any change in the duty cycle of the PWM signal, and further transmits the sampled signal to the controller. The controller obtains the real-time duty cycle of the PWM signal when the voltage of the sampled signal reaches a threshold voltage, and further calculates the exact resistance of the sensor according to the obtained real-time duty cycle of the PWM signal and the threshold voltage. An electronic device with the resistance-measuring circuit is also provided.

Abstract: An impedance correction device and a method thereof are provided. A step generator is used to generate a step signal and send to a circuit under test. A reflected signal returned back from the circuit under test is used as a measurement signal; and the measurement signal can be measured to obtain a characteristic impedance value. When the measurement signal is greater than the initially measured step signal, an impedance value of a correction resistor is increased; when the measurement signal is smaller than the initially measured step signal, the impedance value of the correction resistor is reduced. Through adjustment of the correction impedance value, impedance matching between the correction impedance value and the characteristic impedance value is achieved.

Abstract: A system and method for measuring a characteristic impedance of a transmission-line comprises transmitting energy to the line, and shortly after measuring the voltage/current involved and thus measuring the equivalent impedance. The measured characteristic impedance may then be used in order to determine the termination value required to minimize reflections. In another embodiment, the proper termination is set or measured by adjusting the termination value to achieve maximum power dissipation in the terminating device. The equivalent characteristic impedance measurement may be used to count the number of metallic conductors connected to a single connection point. This abstract is not intended to limit or construe the scope of the claims.

Abstract: A resistance-measuring circuit includes a controller for outputting a PWM signal and further for adjusting the duty cycle of the PWM signal, and a sampling circuit for processing the PWM signal and transmitting the processed PWM signal to the sensor. The sampling circuit samples the signal outputted from the sensor to generate a sampled signal with the voltage thereof changing according to any change in the duty cycle of the PWM signal, and further transmits the sampled signal to the controller. The controller obtains the real-time duty cycle of the PWM signal when the voltage of the sampled signal reaches a threshold voltage, and further calculates the exact resistance of the sensor according to the obtained real-time duty cycle of the PWM signal and the threshold voltage. An electronic device with the resistance-measuring circuit is also provided.

Abstract: An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses.

Abstract: A cable testing system that tests cable includes a pulse generation module that transmits a first pulse on a first communications channel of the cable. A sampling module waits a predetermined time period after the pulse generation module transmits the first pulse and then detects a first amplitude of a reflected signal on a second communications channel of the cable. A time domain reflection (TDR) module receives the first amplitude and verifies proper operation of the cable based on the first amplitude. The predetermined time period corresponds with an estimated roundtrip propagation delay of the first pulse when the first pulse is reflected back to the cable testing system after traveling a first predetermined distance along the cable. The sampling module incrementally increases the predetermined time period during subsequent iterations of a cable test in order to verify proper operation of a predetermined segment of the cable.

Abstract: A system and method for measuring a characteristic impedance of a transmission-line comprises transmitting energy to the line, and shortly after measuring the voltage/current involved and thus measuring the equivalent impedance. The measured characteristic impedance may then be used in order to determine the termination value required to minimize reflections. In another embodiment, the proper termination is set or measured by adjusting the termination value to achieve maximum power dissipation in the terminating device. The equivalent characteristic impedance measurement may be used to count the number of metallic conductors connected to a single connection point. This abstract is not intended to limit or construe the scope of the claims.

Abstract: There is provided an insulation resistance detecting apparatus that accurately calculates an insulation resistance value in real time.

Abstract: A method of determining a size of an optical disc inserted into an optical disc drive is disclosed. The method includes driving a turntable motor of the optical disc drive to rotate the optical disc at a predetermined rotation frequency for reading data stored on the optical disc, measuring a rotation frequency of the turntable motor, applying a kick-pulse voltage to the turntable motor of the optical disc drive for a predetermined period of time, measuring a change in the rotation frequency of the turntable motor after applying the kick-pulse voltage, comparing the change in the rotation frequency of the turntable motor to a threshold value, and determining that the optical disc is an 8 cm disc when the change in the rotation frequency of the turntable motor is above the threshold value.

Abstract: A loop impedance meter is provided for testing an AC electrical main supply incorporating a residual current device. The loop impedance meter includes an electrical control circuit for connecting a load resistance intermittently between the AC main supply terminal and the earth terminal to insure a potential difference between those terminals and to provide an indication of the loop impedance of the AC main supply from that potential difference. The control circuit includes an electronic switch in series with the load resistance, and arranged to open and close the electronic switch by applying a plurality of voltage pulses. The width of the voltage pulses is less than a millisecond, causing a series of measurement pulses of different widths to flow through the load resistance. The control circuit is arranged to process the results of measuring the loop impedance by extrapolating to the effective impedance at the AC mains supply frequency.

Abstract: A loop impedance meter for testing an A.C. electrical mains supply, including an electronic control circuit for connecting a load resistance intermittently between the A.C. mains supply terminal and the earth terminal to measure the potential difference between those terminals and to provide an indication of the loop impedance of the A.C. mains supply from that potential difference, wherein the control circuit is arranged to allow a train of short pulses of current to flow through the load resistance and the loop, the pulse train beginning its sequence with a first train of pulses for preconditioning any residual circuit device (RCD) present in the loop to temporarily desensitize it, wherein the first train of pulses is followed by one or more measurement pulses, the pulses of the first train being of generally increasing width.

Abstract: Apparatus and methods of obtaining information concerning a substance (57) is provided by applying pulses (91, 92, 93) of electromagnetic energy to the substance (57) and evaluating the response of the substance to the electromagnetic energy. The pulses (91, 92, 93) generated by a source (51) are of sufficiently short duration to generate a very broad frequency band of energy. The pulsed energy is directed to the substance (57) to be processed and energy pulses (91, 92, 93) passing through the substance (57) are received (56) and analyzed (66) to determine the properties of substance (57).

Abstract: A protective device includes a signal input intended for connection to a sensor, a signal output intended for connection to an evaluation unit, and an isolation element for galvanically separating the signal input from the signal output. The provision of the protective device prevents a transmission of overvoltages from the sensor to the evaluating unit.

Abstract: Systems and methods are described for transmitting a waveform having a controllable attenuation and propagation velocity. An exemplary method comprises: generating an exponential waveform, the exponential waveform (a) being characterized by the equation Vin=De?ASD(x?vSDt), where D is a magnitude, Vin is a voltage, t is time, ASD is an attenuation coefficient, and VSD is a propagation velocity; and (b) being truncated at a maximum value. An exemplary apparatus comprises: an exponential waveform generator; an input recorder coupled to an output of the exponential waveform generator; a transmission line under test coupled to the output of the exponential waveform generator; an output recorder coupled to the transmission line under test; an additional transmission line coupled to the transmission line under test; and a termination impedance coupled to the additional transmission line and to a ground.

Abstract: An apparatus comprises an edge detector, a memory and a pulse-input engine. The edge detector is configured to receive an input signal and a counter signal. The edge detector is further configured to send a set of time values based on the input signal and the counter signal. Each time value from the set of time values is uniquely associated with a detected edge transition from the input signal. The memory is coupled to the edge detector. The memory is configured to receive from the edge detector the set of time values. The memory is configured to store the set of time values. The pulse-input engine is coupled to the memory. The pulse-input engine is configured to measure a set of pulse-to-pulse delays based on the set of the time values stored in the memory.

Abstract: A current sensor has a power MOSFET Q1, connected between an electric load and a power supply, for controlling current that flows through said electric load, a mirror MOSFET Q2, connected in parallel to said power MOSFET Q1, in which a portion of the current flowing through said power MOSFET flows, and a current detection resistor RC connected between a source electrode of said power MOSFET and a source electrode of said mirror MOSFET. An inverting amplifier circuit CP of the current sensor 3 inverts and amplifies the voltage signal, which has been converted to voltage by the current detection resistor RC, and outputs the signal, thereby converting positive and nega tive voltages generated across the current detection resistor RC to a positive voltage.

Abstract: The present invention describes an arrangement (1) and a method for detecting and transmitting sensor signals, with one or more sensor inputs (33, 46), a processing unit (25, 29, 30, 45), at least one current source (21, 22) which modulates a signal current (32) that can be supplied to an evaluation unit (2) in dependence of a sensor signal from a first sensor element (7) guided through the processing unit, with the signal current being regulated at any time to the predetermined nominal value by means of the processing unit and/or the current source, and the arrangement comprises another signal input (33) for a second sensor (19) as well as a device for transmitting the other sensor signal by way of the signal current (26, 27, 34), with the second sensor that can be connected to the other signal input being furnished with a supply current by way of the other signal input.

Abstract: A measurement system and method for determining a revolution rate of a rotating gear is described. Such a rotating gear can be, for example, a turbine or compressor. The described measurement system and method, for example, can perform highly accurate measurements and can be a fault tolerant system providing high reliability. In one embodiment, an apparatus comprises an edge detector, a memory and a pulse-input engine. The edge detector is configured to receive an input signal and a counter signal. The edge detector is further configured to send a set of time values based on the input signal and the counter signal. The pulse-input engine is configured to measure a set of pulse-to-pulse delays based on the set of time values stored in the memory.

Abstract: A method of measuring current in a pulse count positioning system is provided, wherein various motor conditions such as back up due to cogging and/or gear train affects are taken into account in measuring current pulses that are correlated with the position of an electric device such as an automotive accessory. The method generally comprises measuring current flow through an electric motor at regular intervals, summing the current flow at a second interval, storing the summed current flow as a current pulse occurs, starting a new sum of the current flow, and comparing sums for a previous two sums after a maximum timeout. Accordingly, the method according to the present invention takes various motor conditions into account for a more accurate measurement of current pulses, which correspond with the position of the electric device.

Abstract: Methods for driving a lossy transmission media with an energy wave defined by a an exponential waveform function. The propagation delay and attenuation of the wave is a function of an exponential coefficient, and its propagation velocity is essentially constant and independent of displacement. Utilizing relationships between the propagation velocity, exponential coefficient, attenuation, and transmission line parameters, one may effectively model various transmission media. One may also determine unknown transmission line parameters, waveform exponential coefficients, attenuation, and/or propagation velocities by utilizing those relationships. By modulating the exponential coefficient, information may be encoded onto a waveform.

Abstract: A particle measurement apparatus includes: a particle signal detector for detecting a particle signal; a false signal generator for generating a false signal corresponding to the particle signal; a selector for selecting the particle signal or the false signal, a non-linear amplifier; a first calculator for receiving the signal selected by the selector through the non-linear amplifier to calculate a characteristic parameter; a second calculator for receiving the signal selected by the selector not through the non-linear amplifier to calculate the characteristic parameter; a comparator for including the characteristic parameters calculated by the first and second calculators respectively when the selector selects the false signal; a memory for storing a comparison result of the comparator; and a compensator for compensating the characteristic parameter calculated by the first calculator on the basis of the comparison result when the selector selects the particle signal.

Abstract: A main circuit loop tester includes a wave form generator for producing a current pulse in the form of a narrow spike. The wave form generator is connected to a power stage for producing a high amplitude output. The loop tester also includes a high frequency generator adapted to produce groups of low current pulses at high frequency. A measuring circuit is adapted to measure the resistive and reactive components of the resulting output signals from the main circuit. The tester is particularly useful for testing electrical installations which include residual current devices.

Abstract: A high impedance tap for monitoring traffic over a communication link of a fast Ethernet local area network (LAN). The circuit of the present invention is advantageously used for tapping into a fast Ethernet communication link (e.g., bi-directional communication channel) of a LAN using, for instance, {fraction (10/100)} BaseT Ethernet communication protocol. The novel circuit is particularly useful in point to point communication links (e.g., supporting fast Ethernet communication) where two communication nodes are coupled together using a bi-directional communication link (e.g., two twisted pair cables). Unlike the prior art monitoring probes, the probe of the present invention does not insert itself in series between the communication link, but rather taps onto the communication link in parallel using a high impedance termination circuit thereby leaving the existing communication link undisturbed electrically.

Abstract: In a circuit arrangement for measuring the resistance of a resistance sensor, for instance a wetness sensor, which is connected to an evaluation circuit, there is a galvanic separation, formed preferably by an isolating transformer, between the resistance sensor and the evaluation circuit.

Abstract: A process and a system for the operation of a resistive moisture sensor, in particular on the windshield of a motor vehicle, wherein the conductivity of the moisture sensor is measured shortly after a sudden change in a signal fed to the moisture sensor and measured at at least one later time. Information as to the nature and degree of the dirtying of the windshield is obtained by the measured values.

Abstract: A cell/battery is excited by a time-varying signal that is characterized by periodically making step transitions between discrete levels. The immediate change in a responsive signal is determined by a circuit that is only enabled during a brief "window" of time encompassing a step transition, and which employs a "holding capacitor" to store dynamic conditions existing at the instant of enablement. Action of this "holding capacitor" causes the circuit to only respond to changes in noise signals occurring during the enablement "window" and not to the actual level of the noise itself. By making the "window" sufficiently narrow, noise signals can change by only an acceptably small amount and can be removed by synchronously detecting the response to the step excitation and averaging the result over time. Two embodiments are disclosed. A first embodiment utilizes a step current-signal excitation and a voltage-signal response to directly determine a particular component of incremental resistance.

Abstract: A test assembly for testing integrated circuits. The assembly includes a test chip that is located between the integrated circuit (IC) and a tester. The test chip has a very low input capacitance that approximates an open circuit, and has an impedance that matches the impedance of the integrated circuit and tester. The matching impedance of the test chip reduces the amount of signal ringing between the integrated circuit and tester.

Abstract: A chip detector is an open circuit device that attract metal chips circulating throughout a piece of equipment such as a transmission. If a chip closes the circuit in the chip detector, then it is subjected to a first pulse of energy in an attempt to burn or displace it from the chip detector contacts. The energy content of the first pulse is selected to burn fuzz, which represents chips of an acceptable size. If the chip remains in the chip detector, then it is subjected to one or more additional pulses each having a greater energy content than the first pulse. The number of pulses and their energy contents are recorded to determine the size of the chips captured by the chip detector and to provide a history of the equipment being monitored. If the chip in the chip detector exceeds a predetermined threshold, then an indication is given on a user interface.

Abstract: An apparatus for detecting corpuscles such as blood cells. The apparatus has an aperture and a constant-current source that supplies an electrical current to the aperture for detection of corpuscles. When corpuscles to be investigated pass through the aperture, the electrical impedance changes, producing a signal (herein referred to as the corpuscle signal). The apparatus further includes a pseudo signal-generating means for producing a pseudo signal in the form of pulses. The pseudo signal has a peak value proportional to the amplitude of the input current and is equivalent to the corpuscle signal detected when the corpuscles pass through the aperture. A signal selector means is disposed among the aperture, the constant-current source, and the pseudo signal-generating means. The signal selector means assumes either a first state or a second state.

Abstract: A liquid mixing ratio detecting apparatus is designed so that an oscillation voltage generated by an oscillation unit is applied to one of a differentiating circuit and an integrating circuit, which is constituted by a combination of a capacitor composed of a pair of opposite electrodes for detecting a mixing ratio of a mixed liquid and a resistor, and a mixing ratio detecting unit produces a signal relating to an inclination rate of one of a differential waveform signal and an integration waveform signal, which is generated by one of the differentiating circuit and the integrating circuit, respectively, thereby obtaining a signal representing the mixing ratio of the mixed liquid on the basis of the produced signal relating to the inclination rate of the waveform signal.

Abstract: A method and apparatus for performing an enzyme-linked immuno sorbent assay of a biological substance in a fluid substrate wherein an enzyme conjugate is used to react with the biological substance to cause the release of ions into the substrate. The change in the resistivity of the substrate due to the release of ions is measured, and an analog signal is generated in response thereto. The analog signal is converted into a digital signal, which is quantized and output in a human readable form for indicating the quantity of the biological substance present in the substrate.

Abstract: An electronic level indicator, having a housing including at least one planar surface, at least one gravity responsive sensor mounted on the housing, the sensor constituting at least a part of two branches of an electronic bridge circuit, a pulse generator coupled to the bridge circuit for feeding the bridge circuit with short pulses, a differential amplifier connected to the output of the bridge circuit, an A/D converter connected in circuit for receiving signals from the amplifier and a display unit connected to the output of the converter for displaying numerical data indicative of the inclination of the planar surface.

Abstract: Temperature measurement with thermocouples is made more accurate, and the cost of disposable thermocouples is reduced by locating the cold junction close to the hot junction, utilizing a thermistor in thermal communication with the cold junction in developing a compensating voltage which varies with temperature as does the voltage produced by the cold junction, and applying the compensating voltage to cancel the cold junction voltage. The presence of radio frequency fields in the region of the thermocouple is detected and utilization of the thermocouple voltage is interrupted in intervals when the interference is greater than some preselected intensity. Further, the thermocouple voltage information is utilized to simulate the resistance a thermistor would have at the temperature represented by the thermistor voltage information and that simulated resistance is applied to instrumentation designed to measure temperature with a thermistor.

Abstract: A method for measuring the impedance of a transmission line. The length and D.C. loop resistance of the line are measured. A pulse is transmitted along the line, the pulse having a duration greater than the time required for it to propogate from its source to the end of the transmission line and reflect back to the source. The transmitted and reflected pulses are monitored and the resultant readings converted to a gross impedance measurement. The measurement is then corrected for the "dribble up" effect. The magnitude of the correction is a function of D.C. loop resistance of the line. The corrected measurement is an accurate measurement of line impedance.

Abstract: Apparatus (1) for performing an electrical test on a cable (3) used in local area networks (LAN's). A source (37) produces electrical signals transmitted through the cable. A resistance circuit (43) is interposed between the source and the cable. The amount of resistance interposed by the resistance circuit is adjusted using an adjustment circuit (67). A sensor (71) senses a characteristic of the signal and determines when that characteristic has a value representing an inpedance match between the source and the cable. The sensor circuit provides a command to the adjustment circuit to thereafter maintain the point of adjustment at which the impedances are matched.

Abstract: An electronic level indicator, having a housing including at least one planar surface, a gravity responsive sensor mounted on the housing, the sensor constituting at least a part of two branches of an electronic bridge circuit, a pulse generator coupled to the bridge circuit for feeding the bridge circuit with short pulses, a differential amplifier connected to the output of the bridge circuit, an A/D converter connected in circuit for receiving signals from the amplifier and a display unit connected to the output of the converter for displaying numerical data indicative of the inclination of the planar surface.

Abstract: An impedance meter with improved measurement accuracy obtained by controlling the level of the signal source. The impedance meter comprises a signal source, feedback amplifier, synchronous detector, A/D and control logic. The source level is maintaind by the control logic at a predetermined value by measuring the output of a synchronous detector and intermittently adjusting the level of the source thereby compensating for variations in test object's impedance. Control logic algorithms employed include successive substitution, bisection and linear interpolation.