Abstract: A peak detector circuit to be used in conjunction with an RF tunable volt meter is disclosed which charges a capacitor to a voltage level proportional to the amplitude of an incoming signal and then provides an accurate output signal, for driving a meter, the value of this signal being proportional to the voltage on the capacitor. The accuracy of the meter indicator reading is virtually identical for a particular amplitude regardless of whether the incoming signal is modulated or unmodulated (CW).

Abstract: Method and apparatus for measuring the magnitude of a varying analog signal and for displaying a close approximation of a final stabilized value before the signal reaches stabilization. An analog-to-digital converter converts the analog signal to corresponding digital pulse signals and the digital pulse signals are displayed to an operator. Automatic display-hold circuitry determines the pulse count difference between successive pulse count signals separated by a predetermined time interval, compares the difference to predetermined value, and, when the predetermined value is reached, generates a control signal which locks the displayed value and prevents the display from updating as the analog signal continues to vary. The difference between pulse signals is taken by storing the first signal in an up/down counter and decrementing the counter in response to the second signal.

Abstract: A circuit for determining on a half-wave cycle basis the maximum and minimum voltages of input cyclic line voltages for selected time periods in which the line voltages are rectified to half-waves, and an integrating voltage to frequency converter provides output pulses proportional to the voltage magnitudes of the half-waves with the pulses being counted and placed in a memory and then compared with minimum and maximum previous counts for previous half-waves, to provide an updated minimum and maximum voltage for such half-waves over a period of time or period of half-waves, with provisions for providing resetting strobe pulses at zero voltages of the half-waves and for providing accurate measuring of the pulse outputs in the integrating voltage to frequency converter by modulating the integrator sense voltage and achieving substantially accurate compensation for the effects of timing errors in the V/F converter.

Abstract: The invention provides a method of measuring a voltage with the aid of an analogue-digital converter comprising an integrator and a comparator, in which a first voltage maintaining the integrator on a certain reference potential, a second voltage, bringing the output of the integrator to a certain potential, and a third voltage, discharging the voltage at the output of the integrator are applied to the converter. In this method for measuring instantaneous values of measurement voltages, the first voltage is the measurement voltage and the second voltage is the auxiliary voltage.

Abstract: A voltmeter for selectively indicating the polarity and magnitude of a peak value of voltage. The voltmeter comprises an ammeter, a diode bridge including positive and negative terminals and first and second probe terminals, a capacitor connected to the positive and negative terminals, and variable resistance switching means connected in series between one of the positive and negative terminals and the ammeter for selectively coupling the ammeter across the positive and negative terminals. Filter switching means are provided for selectively coupling the probe terminals to a single polarity of the voltage whereby the voltmeter affords charging of the capacitor so that the magnitude of the positive voltage differential between the positive and negative terminals is substantially equal to the magnitude of the peak value of the single polarity of voltage coupled to the probe terminals.

Abstract: A testing and switching (tester) system is disclosed for information transmission and communications networks and systems and the like. According to a preferred embodiment, a data transmission network is advantageously of the type in which remotely located users or customers are afforded time-shared access to a centrally located computer. The data transmission network includes remotely located switching stations which are linked to the central computer over data transmission lines which include selectively actuated normal and fallback local loops. The network users gain access to the centrally located computer over selectively actuated local lines to the remotely located switching stations. The tester system comprises switching and testing apparatus which includes a programmable tester computer located at the remotely located stations and preferably at the centrally located computer site also.

Abstract: An a.c. input signal is supplied to at least one input terminal to which at least one rectifier is connected for converting the a.c. input signal to a d.c. signal corresponding thereto. A plurality of transistors are connected between the at least one rectifier and a general purpose integrated circuit with a threshold value. Each of plural transistors is controlled in its on/off operation by the d.c. signal from the rectifier in order to control the output potential of the integrated circuit. A plurality of indicators are connected between a d.c. power source and outputs of the integrated circuit to be discretely and sequentially energized to indicate a peak level of the a.c. input signal.

Abstract: A level indicating device having a plurality of diodes connected in series and a plurality of resistors connected in series with light emitting diodes connected between corresponding junctions of both series and means for applying a signal to be indicated to one end of one series and the other end of the other series.

Abstract: A receive line signal detector circuit having slow and fast charging modes of operation to receive both relatively long or short coded information messages. The circuit includes a transistor means to switch the circuit into either of a first slow charging, averaging mode or a second fast charging, peak detection mode of operation depending upon the presence and duration of a sequence of input information signals. The circuit, however, is slow discharging in both the averaging and peak detection modes.

Abstract: A peak detector for electrical signal peaks including a capacitor which is charged, via a rectifying element, to a voltage corresponding to the peak value. At the end of the peak a discharging element connected parallel to the capacitor is activated for a predetermined period of time, with the result that the capacitor is discharged over a fixed fraction of its peak voltage. At the end of the predetermined period of time, the discharging element is reactivated, with the result that a substantially constant voltage remains as a reference level.

Abstract: Apparatus which automatically measures the range and the lower and upper peak values of an unknown signal which varies periodically as a function of time. More specifically, an unknown time varying input signal is applied through a programmable attenuator to one input of a comparator. A direct current voltage which changes in equal incremental steps between predetermined levels is applied to the other input of the comparator. When coincidence occurs an output signal is developed by the comparator responsive thereto. The output signal thus developed is utilized to maintain the attenuator at the range level to which it was set when the coincidence was detected and also causes the reference level applied to the comparator to sequentially change in such a manner as to ascertain the lower and upper peak values of the applied signal.

Abstract: A system for deriving a voltage which is a logarithmic function of peak value of an audio signal, in which the audio input signal is amplified by means of an operational amplifier having bipolar feedbacks through a pair of oppositely poled rectifying junction devices operating over logarithmic portions of their response characteristics, the output of the operational amplifier being applied in opposite polarities to a second pair of rectifying junction devices to rectify a bipolar signal applied thereto, and to control current flow to a storage capacitor, the second pair of devices having a common load which provides a constant current source for slow charge of the storage capacitor in one sense, the second pair of devices providing rapid discharge paths in the opposite sense. In one embodiment either or both pairs of rectifying junction devices can be transistors.

Abstract: A transducer is utilized to convert the eccentricity of a turbine shaft into a sinusoidal electrical voltage signal having a given frequency, amplitude and a DC bias. This electrical signal is provided to a circuit which periodically measures the maximum and minimum peaks of the sinusoidal signal. The frequency at which the latter measurements occur is related to the frequency of the sinusoidal input signal. The maximum and minimum levels of magnitude are stored periodically as DC levels and subtracted from each other to determine the absolute value of eccentricity. In addition the stored minimum value is compared with the sinusoidal signal to reduce the DC bias of the sinusoidal signal to a point where the negative peaks thereof are at zero.

Abstract: The invention discloses an analog voltage memory device comprising an operational amplifier, a reed relay, a capacitor and a MOSFET which are so interconnected to each other that the input voltage applied to the operational amplifier is compared with the output voltage from the MOSFET applied to the noninverting input terminal of the operational amplifier, thereby providing the output voltage whose magnitude follows the level of the input voltage and holds a desired level thereof for a long time. The analog voltage memory device may further include an additional operational amplifier which compares the input voltage with the output voltage and closes the reed relay only when the input voltage is higher than the output voltage so that the source follower output voltage from the MOSFET follows only the peak of the input voltage and remains at the level of this peak.

Abstract: The operative status of an electrical apparatus unit such as a television receiver, incorporating an AC-DC converter, and drawing a substantial amount of current is sensed while differentiating from the usage of a lower amount of current, as when operating in a standby mode. The sensor distinguishes between the standby current waveform and a distinctly different current waveform generated when the AC-DC converter draws current in the mode in which full power is on. The sensor incorporates a reference current detector responsive to the mean of the absolute value of alternating current flowing through a power line to the electrical unit, and a peak value current detector responsive to the peak value of the periodic signal on the power line. A comparator circuit receives outputs from both detectors, and provides an output signal when the ratio therebetween is in excess of a predetermined value, this condition only applying when the AC-DC converter is operative.

Abstract: A pulse peak sample and hold circuit includes a passive input integrator to develop the time of a sample gate. A sensitive comparator develops the gate pulse. A FET and storage capacitor "holds" the actual input amplitude. The circuit is independent of PRF and pulse width.

Abstract: A method for checking the rotation of mechanical workpieces which includes the steps of measuring the workpiece size, processing the measuring signals occurring to generate at least one signal responsive to the measurement of size variations of the workpiece and utilizing the signal for generating control signals to indicate the evenness of the rotation of the piece. An apparatus for practicing the method includes feelers adapted to be brought to the measuring position on the workpiece to supply signals responsive to the size, a processing unit adapted to process the measuring signals detected at succeeding moments to supply information on the geometrical features of the workpiece or its variations, delay and timing units to trigger the processing unit connected with the output of the processing unit and adapted to compare the signals at the output itself with preset reference signals and a consent unit connected with the comparison unit operable as a result of the evenness of the workpiece rotation.

Abstract: The peak amplitudes of alternating components of a composite alternating signal are determined without separating the components from one another, where such components are of different frequencies but have substantially in-phase zero crossings at recurring intervals. In an instrument landing system for aircraft, 90 Hz and 150 Hz signals form the components of a composite modulating signal and the zero crossing points of both components are accurately controlled. The composite 90 and 150 Hz signal is examined by a circuit which produces a reference pulse at the zero crossing time of both component frequencies in the positive direction. The reference pulses maintain digital timing circuitry in synchronism with the 90 Hz and 150 Hz components, and the composite wave form is sampled at each frequency to synchronously detect the peak amplitude of each component in separate detector circuits.

Abstract: An apparatus for measuring and displaying the sag and surge voltage values of an AC power supply. Two inputs are attenuated, filtered and the peak difference is converted to a binary number by an analog-to-digital (A/D) converter. A digital comparator compares these conversions with the values stored in a maximum and minimum register. If the output of the A/D is larger than the contents of the maximum register, the previous maximum register's contents are replaced by the A/D output. If the output of the A/D is smaller than the contents of the minimum register, the previous minimum register's contents are replaced by the A/D output. Dual light emitting diode displays provide a numerical readout of the contents of the maximum and minimum registers.

Abstract: This electronic voltmeter is particularly suited to develop volume unit output readings for appliance type electronic equipment. Seven operational amplifiers are used to selectively and separately energize seven light emitting diodes. Each of the operational amplifiers is provided a reference voltage. Additionally, each operational amplifier is supplied a voltage proportional to the peak voltage of the signal from the electronic equipment. The reference voltage and the voltage proportional to the peak signal from the equipment are compared by each operational amplifier. The operational amplifiers are sequentially switched as the level of the peak signal from the equipment increases. Six of the seven light emitting diodes are energized through transistors. The transistors coact with the operational amplifiers to extinguish all but one light emitting diode. Accordingly, only a single light emitting diode is energized at any time.

Abstract: A peak detector having rise-time enhancement of input signals is comprised of a feedback amplifier including two input terminals and a feedback circuit which interconnects the amplifier output terminal with one of the input terminals; and a peak detecting circuit, including a capacitor, coupled to the other of the amplifier input terminals. The capacitor voltage is applied as an input signal to the feedback amplifier, and abrupt changes in the rise-time portion of the input signals are detected and are used to vary the amplifier feedback so as to enhance the output signal produced by the amplifier during the rise-time portion.

Abstract: A line voltage monitor for monitoring the voltage applied to electrical equipment and for providing an indication or protective disablement of the equipment in the event excessive variations occur in the line voltage. The line voltage monitor includes a steady state voltage sensing means and a transient voltage sensing means for detecting both types of voltage variations.

Abstract: A method and apparatus is provided for compensating for repeatable error signal components which occur with information components. The method provides for detecting the peak amplitude of an error signal and providing a representation thereof, storing the representation, providing a composite electrical signal having the information and error components, detecting the peak amplitude of the composite signal and providing a representation thereof, and combining the stored error signal representation with the composite signal representation to provide an output signal from which the error signal component has been substantially removed.

Abstract: Apparatus is disclosed for detecting and measuring peak-to-peak values in an electrical input signal, the signal comprising at least one positive-going and one negative-going peak and can include waveforms characterized by short duration and fast rise time pulses. In operation, one of the at least one input signal peaks is referenced to a predetermined d.c. voltage level, such as, for example, 0 volts d.c., and an electrical output signal is generated which is representative of the magnitude of the input signal with respect to the predetermined d.c. voltage level. The output signal is generated by electrical circuitry capable of accurately tracking fast rise time pulses and then stretching the other unreferenced at least one peaks to prevent decay thereof.

Abstract: Structure for and a method of detecting peaks in an electric signal comprising circuits for and the steps of converting a selected one of a plurality of analog signals into a current digital signal, comparing the developed digital signal with a digital signal previously developed from the selected analog signal and stored, and replacing the previously developed and stored digital signal with the current digital signal when the current digital signal is greater than the previously developed and stored digital signal and of the same polarity, and providing for readout of the currently stored digital signal in either analog or digital form.Direct reading of the digital output in terms of standard engineering units is provided for. Also, the analog input signal may be directly read at the output of the peak detector and the peak detector may be utilized as a volt meter with a direct current signal passed directly into a digital output portion of the peak detector.

Abstract: A cathode ray tube meter, which may be developed as a VU meter, provides visual representation of the signal levels in each channel of plural signal channels. The signal channels may be the signal channels in a multi-channel audio system. The amplitude of a sawtooth waveform signal from a sawtooth waveform signal generator, which also controls the vertical sweep of an oscilloscope, is compared sequentially with individual d.c. signals developed by respective peak detectors, one being associated with each signal channel, to provide a control signal whenever the amplitude of the sawtooth waveform signal exceed the level of that particular one of the d.c. signals with which it is being compared at any given time. The control signal thus produced is used either as a blanking signal for the vertical sweep or as a signal for effecting the resetting of the sawtooth wave generator. A second sweep signal having a plurality of discrete levels controls the horizontal sweep of the oscilloscope.

Abstract: A level indicating system adapted to provide an indication of the peak-level or the volume unit level of an input signal. The system is comprised of an amplifier to receive the signal; a first changeable time constant circuit; a second changeable time constant circuit coupled to the first time constant circuit; an indicator connected to the second time constant circuit; and a control circuit for changing the respective time constants of the first and second time constant circuits. The indicator selectively provides an indication of the peak-level of the signal or the volume unit of the signal depending upon the particular time constants of the time constant circuit.

Abstract: A peak level indicator using a field effect transistor having a semiconductive substrate with a current path portion, first and second semiconductive regions forming a PN junction therebetween, the first region being capacitively coupled to the current path portion to form a capacitor, and a rectified input signal being applied to the second region. The peak level indicator is provided with a level meter indicating a current through the current path portion.