Showing papers on "Total harmonic distortion published in 1982"
TL;DR: In this article, the harmonic currents, apparent, active, reactive and distortion power associated with a cluster of taper-current type battery chargers, connected to a common bus, were analyzed.
Abstract: This work analyzes the harmonic currents, apparent, active, reactive and distortion power associated with a cluster of electric vehicle taper-current type battery chargers, connected to a common bus. A Monte Carlo simulation using pseudorandum number generators taking into consideration the statistical distribution of the states of charge of the batteries and starting times of the chargers is the primary tool employed in this study.
70 citations
NEC1
TL;DR: In this paper, a tapped MOS analogue delay line based on the switched capacitor technique for realisation of low-power analogue LSIs is fabricated using a VLSI process, with excellent characteristics such as large signal handling capability, low total harmonic distortion of −85 dB for 3V(p-p) input and fast operation speed with negligible charge transfer loss.
Abstract: A tapped MOS analogue delay line based on the switched capacitor technique for realisation of low-power analogue LSIs is fabricated using a VLSI process. Excellent characteristics such as large signal handling capability, low total harmonic distortion of −85 dB for 3V(p-p) input and fast operation speed of more than 1 MHz clock rate with negligible charge transfer loss are obtained.
47 citations
TL;DR: In this article, the performance of five types of battery chargers for use with electric vehicles is compared with a typical electric vehicle battery pack and an 8-hour recharge cycle based on a typical EV battery pack.
Abstract: This report compares the performance of five types of battery chargers for use with electric vehicles. Chargers with and without controlled rectifiers for maintenance of constant charging current and with and without current-smoothing inductors are analyzed. Based on a typical electric vehicle battery pack and an 8 hour recharge cycle, current and voltage waveshapes, current harmonic levels, power, reactive and distortive volt-amperes, voltage distortion factor, and power factor are reported for each charger type.
32 citations
TL;DR: In this paper, a fully integrated four-quadrant analogue multiplier based on switched-capacitor technique for realisation of high-speed and high-density analogue LSIs was developed using a MOS VLSI process.
Abstract: A fully integrated four-quadrant analogue multiplier based on switched-capacitor technique for realisation of high-speed and high-density analogue LSIs was developed using a MOS VLSI process. Excellent characteristics such as low total harmonic distortion of −50 dB for two input signals of 1 Vp-p, large dynamic range of 80 dB and fast operation speed of 2 MHz clock rate were obtained. Application to convolvers and correlators is also demonstrated.
25 citations
TL;DR: The findings are sufficiently encouraging to suggest that direct scaling procedures be employed in future studies of the evaluation of communication systems and the perception of complex signals.
Abstract: Speech quality magnitude estimates (SQME’s) were obtained from 12 normal‐hearing and 12 sensorineurally impaired‐hearing listeners on connected speech samples degraded by changing low‐pass filter cutoff frequency, high‐pass filter cutoff frequency, or percent total harmonic distortion (THD) by linear rectification. Log SQME’s varied linearly with log bandwidth for filtered signals and with log percent undegraded (100−% THD) for linearly rectified signals. Significant variations were found among the slopes of the log–log functions for degradation modes and group‐by‐degradation mode interactions. Slope differences appeared to represent differential sensitivity of the listeners to changes in mode and degree of degradation. The findings are sufficiently encouraging to suggest that direct scaling procedures be employed in future studies of the evaluation of communication systems and the perception of complex signals.
24 citations
TL;DR: In this article, the development of high-power low-frequency diodes, conditions for their operation, and results measured in actual circuits are described, and the improvement of p-i-n diode lifetimes with thicker I-layers or with planar construction has been studied.
Abstract: The development of high-power low-frequency diodes, conditions for their operation, and results measured in actual circuits are described. Harmonic distortion at 500 kHz and 2 MHz has been found to decrease with increasing diode lifetime and forward-bias current. Large reverse bias voltages are necessary at low frequencies to keep the RF voltage swing from penetrating the forward conduction region. The improvement of p-i-n diode lifetimes with thicker I-layers or with planar construction has been studied and the performance of these diodes in a routing switch is reported.
24 citations
Patent•
24 Nov 1982
TL;DR: In this article, the second higher harmonic distortion of the double balanced mixer circuit is suppressed by inverting the phase of an output at an intermediate frequency output terminal 19 out of two output terminals 18, 19 of the circuit further and synthesizing the result with an output of the terminal 18.
Abstract: PURPOSE:To obtain a large converting gain with low distortion and a small local oscillation input by constituting a double balanced mixer circuit by dual gate FETs of common source. CONSTITUTION:The second higher harmonic distortion of the double balanced mixer circuit is suppressed by inverting the phase of an output at an intermediate frequency output terminal 19 out of two output terminals 18, 19 of the circuit further and synthesizing the result with an output of the terminal 18. Since this mixer circuit uses dual gate FETs, the converting gain of the mixer is increased and the local signal input is decreased. Since no amplifier is employed, the distortion characteristic is improved.
17 citations
TL;DR: A general analysis for the calculation of harmonic distortion in single-channel monolithic analog MOS integrated circuits and results are compared with data obtained from a test chip.
Abstract: Presents a general analysis for the calculation of harmonic distortion in single-channel monolithic analog MOS integrated circuits. Power series expressions are obtained for basic stages often used in an analog MOS technology. These include the depletion load inverter, enhancement load inverter, depletion load source follower, enhancement load source follower, and the differential pair. From the power series expressions, the second-order harmonic distortion is calculated. These results are compared with data obtained from a test chip.
17 citations
TL;DR: In 55% (11/20) of ears with low-frequency hearing loss, a decrease in air-bone gap was obtained with HP masking, and it is concluded thatHP masking is of clinical significance for the diagnosis in these patients.
Abstract: Invalid BC determinations may be responsible for many diagnostic misinterpretations in the classification of low-frequency hearing losses To reduce the influence from harmonic distortion, BC thresholds are determined during simultaneous, ipsilateral HP masking and compared with the conventionally obtained BC thresholds Based on normative data a change of ≥ 10 dB HL caused by HP masking is used as the criterion for judging the validity of the conventional BC testing In 55% (11/20) of ears with low-frequency hearing loss, a decrease in air-bone gap was obtained with HP masking, and it is concluded that HP masking is of clinical significance for the diagnosls in these patients
16 citations
01 Sep 1982
TL;DR: In this paper, the authors proposed the use of static AC/DC power convertors for the control of reactive power in a double-bridge scheme, with the two bridges operating back-to-back, to investigate the optimal operating conditions with respect to fundamental power and harmonic distortion.
Abstract: As an alternative to existing thyristor-controlled compensators, the paper proposes the use of static AC/DC power convertors for the control of reactive power. A double-bridge convertor scheme, with the two bridges operating back-to-back, is used to investigate the optimal operating conditions with respect to fundamental power and harmonic distortion. The results indicate that it is possible to maintain quasi-12-pulse operation while providirg the full range of reactive-power compensation, with and without transformers phase-shifting.
11 citations
TL;DR: In this paper, the modulation properties of laser diodes accompanied by coherent reflected waves were analyzed and it was shown that large harmonic distortion is generated by almost different mechanism known from harmonic distortion of the laser diode itself.
Abstract: First of all, we give the basic equations to analyze the modulation properties of laser diodes accompanied by coherent reflected waves, which are based on the rate equation including coherent reflected waves derived by the authors [4]. As a result, it is shown that large harmonic distortion is generated by almost different mechanism known from harmonic distortion of the laser diode itself [5, 6]. Subsequently the harmonic distortion properties are studied experimentally. The above mentioned theory agrees with experimental results qualitatively.
TL;DR: In this paper, a model describing transmission of intensity and frequency-modulated light through a birefringent single-mode fiber with polarization-mode coupling is presented, and it is shown that the distortion caused by the presence of uniform mode coupling is negligible.
Abstract: A model describing transmission of intensity- and frequency-modulated light through a birefringent single-mode fiber with polarization-mode coupling is presented. It is shown that the distortion caused by the presence of uniform mode coupling is negligible. Polarization-mode-dispersion figures of the order of 40 psec and source wavelength shift of 0.1 nm will, in the worst-case situation, limit the bandwidth to 12 GHz with total harmonic distortion of −80 dB.
TL;DR: In this paper, a high-power radio frequency irradiation system that can be tuned automatically is described, which is useful in a nuclear quadrupole double resonance spectrometer, and in other nuclear resonance experiments involving frequency sweeps.
Abstract: A high‐power radio frequency irradiation system that can be tuned automatically is described. A rf magnetic field, H1, of up to 1.8 mT can be maintained over the frequency interval from 0.01 to 6.4 MHz with low harmonic distortion. The system is useful in a nuclear quadrupole double resonance spectrometer, and in other nuclear resonance experiments involving frequency sweeps.
Patent•
21 Jan 1982
TL;DR: In this paper, the authors proposed to decrease the harmonic distortion produced at the process of attenuating processing, by the differential amplification of the output obtained through the input of an input signal and its inversion signal to variable attenuators of the same constitution controlled by a digital control signal.
Abstract: PURPOSE:To decrease the harmonic distortion produced at the process of attenuating processing, by the differential amplification of the output obtained through the input of an input signal and its inversion signal to variable attenuators of the same constitution controlled by a digital control signal. CONSTITUTION:An input signal consisting of sinusoidal waves inputted to a terminal IN is inputted to attenuating means 2,4 of the same constitution for the direct output and the output in phase inversion 3 with zero gain via buffer amplifier A1. The means 2,4 attenuate variably the signal inputted by a digital signal applied to terminals D1-D4. To output points J1,J2 of the means 2,4 with this constitution, the fundamental conponent attenuating the input signal is obtained in opposite phase and the 2nd harmonic component by nonlinear characteristics of transistors Q1-Q4, and Q1'-Q4' is inphase. The output at the points J1,J2 is inputted to a differential amplifier means 5 and it has sufficiently smaller gain in comparison with the signal attenuation by the means 2,4, and the fundamental component only not including the 2nd harmonic is differentially amplified and outputted from a terminal OUT.
TL;DR: In this paper, the steady state and dynamic characteristics of a microprocessor-controlled current source are described, which is based on an eight-thyristor phase commuted bridge, which gives an improved power factor and decreased harmonic distortion.
Abstract: This paper describes the steady-state and dynamic characteristics of a microprocessor-controlled current source. The source is based on an eight-thyristor phase commuted bridge which gives an improved power factor and decreased harmonic distortion. Limiting curves for continuous conduction are presented together with line and thyristor currents in a delta-y input transformer bank. The system's salient characteristics, such as an equidistant firing scheme, a compensator of line voltage variations, and the elimination of a filter in the current feedback loop are described. The transfer function of the current source, with the thyristor switching delays included, is derived and is verified experimentally. It is practically demonstrated that a very fast response is attainable even with a microprocessor-controlled inner current loop.
Patent•
03 Feb 1982
TL;DR: In this article, a ring shape Fe-Co-Si system ferromagnetic alloys 8,9 are provided at the inner circumference of a plate 4 and an upper external circumference of center pole 2 respectively.
Abstract: PURPOSE:To reduce the harmonic distortion of a speaker remarkably, by cooling a Fe-Co-Si system alloy rapidly, and using a ferromagnetic alloy manufactured in thin band as a part of yoke member forming the magnetic air gap. CONSTITUTION:Ring shape Fe-Co-Si system ferromagnetic alloys 8,9 are provided at the inner circumference of a plate 4 and an upper external circumference of a center pole 2 respectively. Since the alloys 8,9 have the constitution that they are jetted and rapidly cooled on a twin roll or a single roll in high speed rotation for the Fe-Co-Si system alloy into thin band, crystal grains are made fine and the permeability and the saturated magnetic flux density are high. As a result, the minor loop by the alternating magnetic field produced from a sinusoidal wave voltage applied to a voice coil 6 is remarkably linearized and harmonic distortion can be reduced.
TL;DR: The intermodulation noise in FM transmission caused by harmonic distortion in the carrier path is calculated by deriving the second- and third-order terms of the distorted signal.
Abstract: The intermodulation noise in FM transmission caused by harmonic distortion in the carrier path is calculated by deriving the second- and third-order terms of the distorted signal. Explicit relations are given in terms of filter delays, harmonic levels, and modulation transfer parameters.
TL;DR: Comparisons of the THD measured by four commercially available systems were made by evaluating eight hearing aids, three times each, and results obtained were significantly different among three of the test instruments.
Abstract: Different types of hearing aid test equipment use different methods to calculate total harmonic distortion (THD) Comparisons of the THD measured by four commercially available systems were made by evaluating eight hearing aids, three times each The results obtained were significantly different (p less than 0001) among three of the test instruments Furthermore approximately 10% of the hearing aids, which met the ANSI S322-1976 specifications for THD when tested with an apparatus that measures true THD, failed this measurement when evaluated on the other three systems
TL;DR: In this article, a two-phase audio-frequency sine-wave oscillator consisting of an integrator and an all-pass network in a closed loop is presented. But the two phases are in quadrature and have the same amplitude, which amplitude is proportional to an external DC voltage.
Abstract: A two-phase audio-frequency sine-wave oscillator consists of an integrator and an all-pass network in a closed loop. Photon-coupled FETs, which introduce no harmonic distortion, are employed as fine-tuning elements to stabilize amplitude and to set the frequency of oscillation. The circuitry guarantees that the two phases are in quadrature and that they have the same amplitude, which amplitude is proportional to an external DC voltage. Frequency can be synchronized, wilhout phase-shift, to an external clock.
TL;DR: It was confirmed that the responses from 10 test subjects could be divided into three significantly different patterns on the basis of the relative amplitudes of the fundamental (first harmonic) and the second harmonic response component as measured by spectral analyses.
Abstract: Preliminary studies (Krogh et al., 1977) indicated pronounced intersubject differences with respect to harmonic distortion in the frequency-following responses (FFRs) elicited by high intensity, low frequency stimuli and recorded by means of surface electrodes from man. In the present investigation it was confirmed that the responses from 10 test subjects could be divided into three significantly different patterns on the basis of the relative amplitudes of the fundamental (first harmonic) and the second harmonic response component as measured by spectral analyses. In three of the subjects the ratio of the fundamental to the second harmonic was greater than 10 dB (which we termed a type I response). In five, the ratio was between 0 and 10 dB (type II response) and in two the second harmonic was equal to or greater than the fundamental (type III response). The possible causes of harmonic distortion in FFRs are discussed, but no definite explanation of the interindividual differences can be given. A psychoa...
01 Jan 1982
TL;DR: A new regulated utility interactive inverter for direct photovoltaic energy feedback to the mains has been realized and a novel maximum power tracking (MPT) strategy based on a simple current peak error detection is described.
Abstract: A new regulated utility interactive (UI) inverter for direct photovoltaic energy feedback to the mains has been realized. The inverter acts as a current source, its output is a sinewave with negligible harmonic distortion and has a projected efficiency of over 90%. A novel maximum power tracking (MPT) strategy based on a simple current peak error detection is described.
TL;DR: Timedomain omain transient analysis is combined with ac steady-state analysis using standard computer-simulation circuit-analysis programs to evaluate low levels of harmonic distortion with appreciably reduced numerical error.
Abstract: A method of accurately determining harmonic levels in nonlinear networks with periodic excitation is described. Timedomain omain transient analysis is combined with ac steady-state analysis using standard computer-simulation circuit-analysis programs to evaluate low levels of harmonic distortion with appreciably reduced numerical error. The technique is useful in a variety of applications such as mixers, rectifiers, power amplifiers, and switching power supplies.
Patent•
28 Jan 1982
TL;DR: In this paper, the authors proposed to improve the S/N to VTR for home use, by excluding nonlinear element from a circuit giving time constant, by adjusting the output of a compressor 23 to a suitable level and subtracted from the original signal at a subtractor 24.
Abstract: PURPOSE:To improve the S/N to VTR for home use, by excluding nonlinear element from a circuit giving time constant. CONSTITUTION:When an output of a compressor 23 is adjusted to a suitable level and it is subtracted from the original signal at a subtractor 24, the frequency characteristic at an output terminal 14 corresponds to the input signal levels. When the input signal level is greater, the output of the compressor 23 including much harmonic distortion is at a very small level in comparison with the input signal level, then the level of the harmonic distortion at the output of the subtractor 24 is small. When the input signal level is small, the output of the compressor 23 is equal to the input signal level, but the compression effect by the compressor 23 is small in this case, resulting that the harmonic distortion is small.
TL;DR: In this paper, the authors review the subject of harmonic distortion from the point of view of the power engineer and consider the meaning of harmonics, what causes them, how they flow in the power engineering process.
Abstract: The paper reviews the subject of harmonic distortion from the point of view of the power engineer. It considers in this context the meaning of harmonics, what causes them, how they flow in the powe...
13 Apr 1982
TL;DR: In this paper, a coherent light source is modulated and coupled to a fiber, dispersion induces harmonics because the light modulators and detectors are not linear; however, when intensity modulated, the optical power varies linearly with modulating signal, and the electric field varies as the square root of the modulating signals, and these nonlinear source effects, when dispersed by a fiber and detected by a square law photodiode, generate harmonic distortion.
Abstract: When a coherent light source is modulated and coupled to a fiber, dispersion induces harmonics because the light modulators and detectors are not linear. However, when intensity modulated, the optical power varies linearly with modulating signal, and the electric field varies as the square root of the modulating signal.1 As a result of this nonlinear dependence on the electric field, the optical spectrum contains sidebands of the modulating frequency and field, the optical spectrum contains sidebands of the modulating frequency and its harmonics. Current modulation of a semiconductor laser also causes wavelength modulation,2 resulting in additional sidebands at harmonics of the modulating frequency. These nonlinear source effects, when dispersed by a fiber and detected by a square law (nonlinear) photodiode, generate harmonic distortion.
TL;DR: In this paper, the effect of fast neutron radiation on the electrical characteristics of power GaAs MESFETs and power GAAs MESSFET amplifiers was evaluated and significant degradation was observed at 1 × 1015 n/cm2.
Abstract: The effect of fast neutron radiation on the electrical characteristics of power GaAs MESFETs and power GaAs MESFET amplifiers has been evaluated. The changes in amplifier power output and intermodulation and harmonic distortion start to occur at neutron fluence of 2 × 1014 n/cm2 and significant degradation is observed at 1 × 1015 n/cm2.
Patent•
10 Dec 1982
TL;DR: In this article, the authors proposed a method to automatically measure a harmonic distortion factor corresponding to different amplitude of a reference alternating signal, by applying a sinusoidal wave being an input application signal to a digital communication equipment after amplitude modulation with a low frequency signal.
Abstract: PURPOSE:To automatically measure a harmonic distortion factor corresponding to different amplitude of a reference alternating signal, by applying a sinusoidal wave being an input application signal to a digital communication equipment after amplitude modulation with a low frequency signal. CONSTITUTION:An output of a triangle wave oscillator 21 is applied to an amplitude modulator 23 via a resistance attenuator 22, and an output of a sinusoidal wave oscillator 1 is amplitude-modulated with the output of the triangle wave oscillator 23. The output of the modulator 23 is inputted to a system 4 to be measured via a resistance attenuator 2 and a low-pass filter 3, and the output of the system 4 is applied to a band-pass filter 6 selecting harmonics and a band-pass filter 5 selecting the applied frequency. The output of a differential amplifier 11 to which the output of the filter 5 and 6 are inputted via detectors 7 and 8 and logarithmic converting amplifiers 9 and 10 is inputted to a peak detector 25. The peak detector 25 is reset at each one period of the triangle wave with a detector 24 and the worst value of the distortion factor can be displayed on a level indicator 12.
Patent•
27 Sep 1982
TL;DR: In this article, the harmonic distortion of a band pass filter is reduced by passing an input signal through a heterodyne circuit, after the frequency change in the input signal is decreased through the use of a heterogeneous circuit.
Abstract: PURPOSE:To reduce the distortion produced in a band pass filter, by passing an input signal through a band pass filter, after the frequency change in the input signal is decreased through the use of a heterodyne circuit. CONSTITUTION:An output of a voltage controlled oscillator VCO1 (frequency f2) and an input signal (frequency f1) applied to an input terminal IN are multiplied at a multiplier 2 to for a signal in frequency f3=f1-f2. When this signal passess through a band filter 4, it becomes a signal in frequency f4=f3'+f2, after it is multiplied with the output of the VCO1. On the other hand, when an output frequency f2 of the VCO1 is controlled so that it can be changed by a.DELTAf proportional to the change DELTAf in the input signal frequency, the f3 becomes as f3= (f1-f2)+(1-a)DELTAf, and the f3' and the f4 are as shown in EquationsIand II. When the a in Equation above is close to 1, an output reducing the harmonic distortion (DELTAf) of the DELTAf can be obtained.
Patent•
25 Jan 1982
TL;DR: In this paper, a low-pass filter is operated by the detection current of the detecting means 11 to reduce multipath distortions of a stereo output signal sent from a stereophonic demodulation stage 6 to audio amplification stages 7 and 8.
Abstract: PURPOSE:To reduce the multipath distortion of a stereophonic output signal by detecting the existence of a multipath by detecting the existence of the higher- harmonic distortion of a pilot signal, and then by operating a low-pass filter by using the detection signal. CONSTITUTION:Among higher-harmonic distortions of a pilot signal contained in an FM signal rceived by an antenna 1, a detecting means 11 detects the existence, specially, of the tertiary higher-harmonic distortion of 57kHz to detect the existence of a multipath. When it is detected, a low-pass filter 12 is operated by the detection current of the detecting means 11 to reduce multipath distortions of a stereophonic output signal sent from a stereophonic demodulation stage 6 to audio amplification stages 7 and 8. Consequently, distortion components specially of 4-10kHz which catch ears are reduced.