Abstract: An integrated circuit according to the present invention includes application-specific circuitry and an embedded counter assembly capable of measuring the frequency of one or more clock signals, which may be generated internally by the integrated circuit or externally by one or more sources external to the integrated circuit. The embedded counter assembly utilizes a reference clock signal having known characteristics, and measures the frequency of an unknown clock signal based upon the reference clock signal. The embedded counter assembly is capable of measuring the frequency of internal clock signals that are otherwise inaccessible via external output pins.

Abstract: A Sensor for detecting radio-frequency oscillations of a voltage, and an arrangement of a sensor for detecting radio-frequency oscillations of the voltage in a line. The sensor (10) has a capacitor (15) whose first connection can be connected to the line (11). According to the invention, the second connection of the capacitor is associated with a current transformer (18) and a bush (19) for outputting a measured signal. The invention furthermore provides for a sensor (10) to be arranged in an intermediate space (13) between the line (11) and a shield (12).

Abstract: The circuit arrangement serves to identify an input signal (s1) assigned to a predetermined signal class. It comprises signal-matching electronics (1) responsive to a current component and/or a voltage component of the input signal (s1) and providing a corresponding output signal (s2). By means of signal recognition electronics (2) of the circuit arrangement, the output signal (s2) is transformed into a recognition signal (c1) representative of the signal class.

Abstract: A method and an apparatus for measuring the instantaneous frequency of FM modulated signals, includes sampling, instantaneous frequency computing, and lowpass filtering. FM modulated signal are sampled at prescribed intervals to provide digitized FM signal. The instantaneous frequency is computed by manipulating the digitized FM signal mathematically using a new mathematical equation proposed in this invention to provide the instantaneous frequency based on digitized FM signal samples. More accurate instantaneous frequency values can be obtained by filtering the computed instantaneous frequency values using a lowpass filter.

Abstract: A protective relay determines frequency of an AC signal of an electric power system. The protective relay includes a circuit measuring the AC signal period between zero crossings to provide a measured period value. A microprocessor includes a random access memory having a five-element array, which collects five consecutive values of the measured period values. A microprocessor routine chooses a median from the measured period values and generally determines the frequency based upon the median. The median is ignored and the previously determined line cycle period is adjusted to determine the new line cycle period if: an absolute value of a difference between a last value of the measured period values and a previously determined line cycle period is not less than a predetermined value; and the last value of the measured period values is within the limits of the array.

Abstract: A system clock for a system for measuring at least one given quantity having a value which does not vary significantly from a given frequency, the system clock comprises a controller for sampling said given quantity at a rate determined by an oscillator frequency, and a programmable oscillator for generating the oscillator frequency, said programmable oscillator being programmable to produce said oscillator frequency at a frequency which is substantially identical to a high order harmonic of said given frequency of the quantity to be measured.

Abstract: The system obtains the three phase voltages on the power line VA, VB and VC, either from a local primary or local alternative source. The selected local source voltages are then applied through switches, respectively, which are normally closed but are open in the event that the associated pole of each voltage phase is open. The voltages from the closed switches are applied to a calculating circuit which produces a composite of the three voltages in accordance with a preselected formula. The composite voltage output is then normalized and applied to a conventional frequency determination (estimating) circuit. This output is an accurate system frequency for use by the protective relay.

Abstract: A method for measuring a frequency f=&ohgr;/2&pgr; of a sinusoidal signal V(t)=Asin(&ohgr;t+&agr;) with an essentially constant amplitude A. Measured values are registered in the form of the instantaneous level of the signal V(t), V(t−h) and V(t−2h)at three points of time separated by a predetermined measuring period h, which corresponds to a measurement frequency fs=1/h.

Abstract: A frequency change measuring device comprises frequencydivider for frequency dividing a measuring signal to produce frequency-divided signals, first counter for counting the frequency-divided signals to calculate frequency-division numbers, frequency division numbers transmitter for transmitting the frequency division numbers in synchronism with the frequency-divided signals, frequency division numbers receiver for receiving the frequency division numbers transmitted from the frequency division numbers transmitter, second counter for counting outputs of a reference clock generator synchronized with a timekeeping device that keeps the standard time, latch unit for latching a count of frequency outputs of the reference clock generator synchronous for generating reference clocks on the basis of signals synchronous with the frequency division numbers, and operations unit for determining a frequency change on the basis of the count and the frequency division numbers.

Abstract: Measurements are obtained of a signal within each one of multiple ranges of a parameter. For each range a representative measurement value is derived together with the extent of the range. A respective graphical display element is defined for each range of the parameter, a first dimension of each display element (such as its height) being indicative of the representative measurement value for the respective range of the parameter, and a second dimension of the display element (such as its width) being indicative of the extent of that respective range of the parameter. A display of the measured signal throughout the multiple ranges of the parameter is generated, with the graphical display elements superimposed at positions corresponding to the respective ranges of the parameter.

Abstract: A clock skew measuring apparatus for measuring a clock skew between a plurality of clock signals to be measured in a device under test, includes: a clock signal selecting element for receiving clock signals and outputting them by selecting one of the clock signals one by one; and a clock skew estimator for receiving a reference signal input to the device under test and the clock signals to be measured selected by the clock signal selecting element one by one and for obtaining the clock skew between the clock signals to be measured.

Abstract: A timing signal generator including a direct digital frequency synthesizer (DDFS), a divide-by-N counter, and a pattern generator, produces a TIMING signal conveying a timed sequence of pulses. The pattern generator produces a sequence of data pairs (FREQ,N), with each pair being produced in response to each pulse of the TIMING signal and indicating a time interval that is to occur between that TIMING signal pulse and a next TIMING signal pulse. The DDFS produces an output sine wave signal (SINE) having a frequency controlled by the current FREQ data output of the pattern generator. The divide-by-N counter produces the timing signal pulses. It counts cycles of the SINE signal occurring since it last produce a TIMING signal pulse and generates a next TIMING signal when it has counted the number of SINE signal pulses indicated by the current N data output of the pattern generator.

Abstract: A method of measuring frequency samples a waveform, calculates waveform voltages based on an initial time base and adjust the time base for a particular waveform to determine the actual frequency of the measured AC power. A microprocessor can be used to implement the method so a small quantity of electronic elements is required, and the manufacturing cost is low.

Abstract: A data handling system that effectively detects and diagnoses manifestations of excessive transducer instability. For example, some embodiments identify shouldering and baseline pop instabilities in a digital servo channel. A preferred method of the present invention involves detecting a precise time at which a first feature in the received signal is encountered. Then, after a preset delay, a first level of the received signal is sampled. Then, after waiting until after a second feature in the received signal occurs, a second level of the received signal is sampled. Finally, at least one digital signal is generated so as to indicate whether an arithmetic combination of the first and second levels falls outside a stability-indicative range. A preferred device of the present invention includes a transducer, a peak detector configured to receive a signal from the transducer, two delay elements, two sampling circuits, and an output.

Abstract: The invention provides a structure, method and means for receiving a reference frequency and a variable frequency, differentiating the frequencies, and generating a logic pulse in response to a first frequency leading a second frequency, the frequencies having a small phase difference. In an aspect, the invention maintains a signal when the reference frequency and the variable frequency transition. In another aspect, the invention provides additional timing balance to prevent early generation of the logic pulses. In another aspect, the logic pulses drive a charge pump used in one of a phase-locked loop and a delay-locked loop.

Abstract: A method and an apparatus for measuring the instantaneous frequency of FM modulated signals, comprises a sampling means, an instantaneous frequency computing means and a lowpass filtering means. The sampling means samples FM modulated signal at prescribed intervals to provide digitized FM signal. The instantaneous frequency computing means manipulates the digitized FM signal mathematically using a new mathematical equation proposed in this invention to provide the instantaneous frequency based on digitized FM signal samples. More accurate instantaneous frequency values can be obtained by filtering the computed instantaneous frequency values using a lowpass filter.

Abstract: A system for, and method of, analyzing a forced or unforced oscillator. In one embodiment the system includes: (1) a transformation circuit that transforms a frequency-modulated waveform representing an output of the oscillator into a function based on at least two time scales and (2) a numeric analyzer, associated with the transformation circuit, that warps at least one of the at least two time scales and thereafter numerically analyzes the function to determine a frequency thereof.

Abstract: A method of measuring frequency samples a waveform, calculates waveform voltages based on an initial time base and adjust the time base for a particular waveform to determine the actual frequency of the measured AC power. A microprocessor can be used to implement the method so a small quantity of electronic elements is required, and the manufacturing cost is low.

Abstract: The system obtains the three phase voltages on the power line VA, VB and VC, either from a local primary or local alternative source. The selected local source voltages are then applied through switches, respectively, which are normally closed but are open in the event that the associated pole of each voltage phase is open. The voltages from the closed switches are applied to a calculating circuit which produces a composite of the three voltages in accordance with a preselected formula. The composite voltage output is then normalized and applied to a conventional frequency determination (estimating) circuit. This output is an accurate system frequency for use by the protective relay.

Abstract: A foreign material interference detection apparatus for an opening/closing member that reduces the calculation load for foreign material interference determination processing. A rotating speed detection sensor detects the rotating speed of a motor and provides its detection signal SP to a computer. The computer obtains a load determination rotating cycle t1 from the detection signal SP. Based on the load determination rotating cycle t1, the computer determines foreign material interference when it determines that the rotating speed is fluctuating due to a load that is the same as that produced when a foreign material is interfering with the opening/closing member and when the determination is made consecutively a predetermined number of times.

Abstract: A sweep controller supplies a current to a YTO(YIG-Yttrium-Iron-Garnet Tuned Oscillator) from a current drive circuit in such a manner that frequencies corresponding to a first range in an oscillation frequency of the YTO designated as a desired frequency range for analysis with one sweep, and a second range designated as a frequency range higher than the first range for the analysis with the next one sweep are oscillated by the YTO. Moreover, the sweep controller outputs an instruction for increasing the current flowing through the YTO from the current drive circuit over a part of a period between an end of the first range and a start of the second range in order to shorten the period between the end of the first range and the start of the second range when it is detected that a difference between an end frequency of the first range and a start frequency of the second range is larger than a predetermined frequency difference.

Abstract: The invention relates to a method for detecting measurement data on coordinate measuring and digitalizing machines. Usually, the position of the machine, e.g. the x-, y-, z-coordinate, has to be linked to a value, e.g. distance value, that is generated by calipers or a sensor for obtaining the space coordinates of a surface point during detection of geometries on a coordinate measuring machine or digitalizing machine. It has to be guaranteed that the information of the coordinate measuring machine and the sensor originate from the same measuring time, whereby said information has to be linked, when a measuring sensor is used for detecting the geometry of an object, e.g. a free forming surface, and when said sensor is moved during detection. When the measuring times of the coordinate measuring machine and the sensor are determined by an electric signal (trigger), the equality thereof can be guaranteed and the influence of signal propagation delays can be excluded.

Abstract: A frequency test circuit (200) includes a built-in self test (BIST) circuit (212) which provides for testing of a frequency generating circuit such as an oscillator circuit (100). The test circuit (200) includes circuit stages (202-208) which help produce a reference signal (210) which has substantially the same frequency as that produced by the oscillator circuit (100) when it is operational. Since the low current oscillator circuit (100) can fail at any one of the divider or level shifting stages (106-112), the test circuit (200) can determine if the reference signal and the output signal of the oscillator have substantially the same frequency and produce a test condition signal indicative of either a pass or failed test at test port (214).

Abstract: A frequency synthesized signal generator outputs a frequency synthesized signal having a frequency equal to a repetition frequency of a signal under test by employing a reference signal. A phase comparator detects a phase difference between a phase of the frequency synthesized signal and a phase of the signal under test, and outputs a phase difference signal. A voltage control oscillator generates a reference signal phase-synchronized with the signal under test based on the phase difference signal output from the phase comparator, and feeds the reference signal back to the frequency synthesized signal generator. A sampling signal generator circuit generates a sampling signal applied to a sampling section by employing the reference signal output from the voltage control oscillator.

Abstract: A method and an apparatus for measuring the instantaneous frequency of FM modulated signals, includes sampling, instantaneous frequency computing, and lowpass filtering. FM modulated signal are sampled at prescribed intervals to provide digitized FM signal. The instantaneous frequency is computed by manipulating the digitized FM signal mathematically using a new mathematical equation proposed in this invention to provide the instantaneous frequency based on digitized FM signal samples. More accurate instantaneous frequency values can be obtained by filtering the computed instantaneous frequency values using a lowpass filter.

Abstract: A phase difference to duty-cycle circuit converts a phase shifted signal and a reference signal into a single signal having a duty cycle that is a function of the phase difference between the two signals. The single signal may be further converted to a single direct current (DC) value before being transmitted to external measurement circuitry. The external measurement circuitry, by simply measuring the magnitude of the DC signal, can determine the phase difference between the phase shifted signal and the reference signal. In an alternate embodiment, the phase shift in the target bit of a bit pattern is determined based on measurements of the DC voltage value of the shifted target bit pattern, the DC voltage value of first bit pattern comprising a non-shifted bit pattern representing a zero phase shift of the target bit, and a DC voltage value of a bit pattern comprising a non-shifted bit pattern representing a 100% phase shift of the target bit.

Abstract: A digital frequency detector (10) and method for digitally detecting arbitrarily small phase changes between a signal waveform and a reference waveform. Both the reference waveform and the signal waveform are sampled at a rate related to the clock frequency fc, and separately fed into two arrays of simple frequency detectors (12, 14). Each simple frequency detector in each array has a different starting phase with respect to the reference waveform and the signal waveform respectively. Phase slips between the reference waveform and the sampling frequency and phase slips between the signal waveform and the sampling frequency are measured by the detector arrays (12, 14). These phase slips, called “slip events”, are combined in circuit (16) which produces an output indicative of phase slips between the reference waveform and the signal waveform. Using this phase slip information, the instantaneous frequency difference between the signal and reference waveforms can be determined.

Abstract: Improved devices, systems, and methods use a Non-Liner Optic (NLO) to effect a conversion of an input laser energy to an output energy. The output energy will have a wavelength which is different than the input energy, and the conversion will vary in response to both an angle of the energy relative to the NLO and a temperature of the NLO. Passive control over the angle of the NLO based on thermal expansion of a member thermally coupled to the NLO can compensate for the temperature-induced change in the conversion so as to maintain a desired output frequency, conversion efficiency, phase matching, and/or the like.

Abstract: A system clock for a system for measuring at least one given quantity having a value which does not vary significantly from a given frequency, the system clock comprises a controller for sampling said given quantity at a rate determined by an oscillator frequency, and a programmable oscillator for generating the oscillator frequency, said programmable oscillator being programmable to produce said oscillator frequency at a frequency which is substantially identical to a high order harmonic of said given frequency of the quantity to be measured.

Abstract: A method of testing and/or monitoring the system frequency of a microcontroller, in which the working frequency of a voltage-regulated oscillator or VCO, which is in an operative connection with the microcontroller, is measured, and the system frequency being determined and/or checked on the basis of the measured working voltage.

Abstract: The invention relates to the field of frequency measuring, in particular to extremely accurate difference frequency measuring as it is used in the area of measuring instruments, e.g. in scanning atomic force microscopes or other scanning probe microscopes, or in the area of thermogravimetry for determining extremely small masses in the ng-range. The invention relates in particular to the principle of such a hybrid frequency measuring device or frequency detector, i.e. a frequency measuring device or frequency detector comprising both digital and analog components or groups of components. The invention also relates to an advantageous use of such a frequency detector for evaluation of the frequency measurements of a scanning probe microscope. A frequency measuring arrangement can be at least partly integrated in a measuring head of a scanning probe microscope, thus enabling a robust, and at the same time sensitive, measuring arrangement.

Abstract: The present invention provides a system interconnection protective device. A command for dropping a voltage is issued when the frequency change rate of a private generator set is positive, and a command for raising a voltage is issued when the frequency change rate is negative. The output voltage of the private generator set is varied by supplying an automatic voltage regulator with the voltage variation reference obtained by assisting the commands based on a rough tendency of frequency variations. Thus, a sole operation of the private generator set, which interconnects with a system, can reliably and easily be detected and protected on the side of the private generator set by enlarging the frequency variations without using any expensive transfer breaker.

Abstract: A power spectrum waveform is obtained by logarithmically amplifying a signal received by a frequency-sweep operation, detecting the amplified output of each frequency sweep, converting the detected output into a digital signal value in decibels, and converting this digital signal value into an antilogarithmic power value in watts for each display point within the width of the frequency sweep. Upon completion of the frequency sweep operation, the power values which have been converted into antilogarithmic values for each frequency sweep are averaged for each display point, the average power values are converted into logarithmic values, and the logarithmic values are displayed as a spectrum display.

Abstract: A mode selection method for signal analyzers having alternative swept and Fast Fourier Transform (FFT) modes of operation enables tradeoffs between measurement speed and dynamic range to be optimized in selecting between the alternative operating modes. The method includes setting the signal analyzer to either a manual state or an automatic state according to a first input to a user interface. When the manual state is set, the analyzer is operated in either the swept operating mode or the FFT operating mode according to a second input to the user interface. When the automatic measurement state is set, a third input to the user interface determines whether measurement speed or dynamic range is optimized. Measurement speed is optimized according to a first optimization scheme and dynamic range is optimized according to a second optimization scheme.

Abstract: A system for providing information on the clock frequency of a data source in a digital receive-transmit system, where the clock frequency value of the data source is sent at a preset rate (FP), comprising a first signal (FS) at a first frequency (FQ1) associated with the data source, a second signal (FT) at a second frequency (FQ2) associated with the transmission system, measuring means for the first frequency (FQ1) of the first signal (FS) against the second frequency (FQ2) of the second signal (FT). According to the present invention the measuring means (CP, CN, CM) operates at a measuring rate (F) higher than the preset rate (FP) and a post-processing means (P) is provided to send a coded signal (U′) to the receiver (R).

Abstract: A method of increasing the system stability of an electricity supply network including the steps of locating programmable frequency sensitive relays at load shedding points within the network. Each relay controls one or more loads and contains programmable disconnect and reconnect conditions. One or more of the loads are disconnected from the network upon a relay detecting the programmable disconnect conditions. Each relay reconnects the load to the network when it detects the programmable reconnect conditions. Each relay includes a device for detecting the network frequency, a micro-processor including memory and software and a switching mechanism to disconnect and reconnect one or more of the loads. Each relay is programmed from a centralized network stability manager which can designate programmable conditions for each relay. The communications between each relay and the stability manager can be via broadcast or sequential point-to-point communications.

Abstract: A frequency change measuring device comprises frequencydivider for frequency dividing a measuring signal to produce frequency-divided signals, first counter for counting the frequency-divided signals to calculate frequency-division numbers, frequency division numbers transmitter for transmitting the frequency division numbers in synchronism with the frequency-divided signals, frequency division numbers receiver for receiving the frequency division numbers transmitted from the frequency division numbers transmitter, second counter for counting outputs of a reference clock generator synchronized with a timekeeping device that keeps the standard time, latch unit for latching a count of frequency outputs of the reference clock generator synchronous for generating reference clocks on the basis of signals synchronous with the frequency division numbers, and operations unit for determining a frequency change on the basis of the count and the frequency division numbers.

Abstract: A method for measuring a fundamental frequency of a power system comprises sampling voltage and current waveforms associated with the power system, wherein the voltage and current waveforms are characterized by a fundamental frequency component that may vary over time. Next, determine whether, according to a prescribed frequency tracking criterion, a present value of the fundamental frequency can be measured using voltage samples. If so, measure the fundamental frequency using the voltage samples, and set a best available value (“freq”) equal to the measured value based on voltage samples. If the fundamental frequency cannot be measured using the voltage samples, determine whether, according to the prescribed frequency tracking criterion, the present value of the fundamental frequency can be measured using current samples. If so, measure the fundamental frequency using the current samples and set the best available value equal to the measured value based on current samples.

Abstract: A phase difference to duty-cycle circuit converts a phase shifted signal and a reference signal into a single signal having a duty cycle that is a function of the phase difference between the two signals. The single signal may be further converted to a single direct current (DC) value before being transmitted to external measurement circuitry. The external measurement circuitry, by simply measuring the magnitude of the DC signal, can determine the phase difference between the phase shifted signal and the reference signal. In an alternate embodiment, the phase shift in the target bit of a bit pattern is determined based on measurements of the DC voltage value of the shifted target bit pattern, the DC voltage value of first bit pattern comprising a non-shifted bit pattern representing a zero phase shift of the target bit, and a DC voltage value of a bit pattern comprising a non-shifted bit pattern representing a 100% phase shift of the target bit.

Abstract: A method and apparatus for measuring the frequency of a desired resonant mode of a crystal arrangement, or other two-port device, during an automated operation. The crystal arrangement, or other two-port device, is placed into a test circuit and subjected to a sinusoidal test signal of known frequency. Based upon the output response of the crystal arrangement to the test signal, the frequency of the test signal is changed such that the test signal rapidly converges on a desired mode of operation of the crystal arrangement. This is accomplished by first noting a desired increase in amplitude of the output response of the crystal arrangement, followed by measuring an error signal related to the desired crystal arrangement mode of operation. When the error equals a predetermined value the frequency of the sinusoidal test signal is the frequency of the desired mode.

Abstract: A method is provided for use on a parametric tester that allows the parametric tester to more effectively and precisely measure the output frequency of a periodic pulse signal generating means. The first step is to down convert the output frequency of the periodic pulse signal generating means to about 1 Hz. Then, the frequency-downconverted pulse train is sampled to thereby obtain a series of sampled signals In accordance with the magnitudes of the sampled signals, the sampled signals are registered to be at either a high-level state, an low-level state, or a intermediate-level state. Then, the integration time and the delay time involved in the sampling process are registered. The sampling process is continued until at least two sampled signals at the low-level state are registered. Based on these parameters, a delta transition time for the first intermediate-level state and a second delta transition time for the second intermediate-level state can be obtained.

Abstract: A system for designing integrated circuits that use frequency synthesizers to ensure testability. A testability circuit is added or connected to the frequency synthesizer that will receive allow the integrated circuit to operate in a system mode for normal function and in a test mode during testing. In the test mode, the testability circuit will inhibit the reset signal from initializing the integrated circuit until the frequency synthesizer has reached phase lock. The testability circuit may be implemented as a component in the frequency synthesizer cell in an ASIC design system such that anytime the frequency synthesizer is used, the integrated circuit is testable.