Home
>
Journals & magazines
>
IEE Proceedings G (Electronic Circuits and System...
>
Volume 131
Issue 4
IEE Proceedings G (Electronic Circuits and Systems)
Volume 131, Issue 4, August 1984
Volumes & issues:
Volume 131, Issue 4
August 1984
High-frequency design of sinusoidal oscillators realised with operational amplifiers
- Author(s): J.L. Huertas ; A. Rodriguez-Vazquez ; B. Perez-Verdu
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 137 –140
- DOI: 10.1049/ip-g-1.1984.0028
- Type: Article
- + Show details - Hide details
-
p.
137
–140
(4)
The use of slew-rate models for designing RC active oscillators is discussed. It is shown that a precise modelling of the oscillator behaviour is obtained for frequencies beyond the ordinary application range of operational amplifiers. Based on that model, a design procedure is developed, and it is applied in the paper to the design of Wien-bridge oscillators, giving theoretical as well as practical results. Low-distortion oscillations may be obtained up to 100 kHz using standard operational amplifiers.
Nonsymmetric multivibrators with an auxiliary RC-circuit
- Author(s): I.M. Filanovsky ; V.A. Piskarev ; K.A. Stromsmoe
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 141 –146
- DOI: 10.1049/ip-g-1.1984.0029
- Type: Article
- + Show details - Hide details
-
p.
141
–146
(6)
The paper describes the design of nonsymmetric multivibrators. These multivibrators include a large capacitor which is charged by a current source and discharged periodically by the comparator controlled switch. The distinctive feature of these multivibrators is an auxiliary RC-circuit of a small time constant which is connected between the large capacitor and the comparator. The voltage at the output of this auxiliary circuit follows the voltage at the large capacitor during the first quasistable state (space). The recharge of the small capacitor in the auxiliary circuit is used to determine the duration of the second quasistable state (mark). Three modifications are considered. If the space/mark ratio is small (̃10) the additional buffer amplifier is inserted between the large capacitor-and the auxiliary RC-circuit. For medium (̃ 100) space/mark ratio multivibrators the buffer amplifier is omitted and the capacitor in the auxiliary RC-circuit absorbs the functions of the large capacitor (which can be omitted also). For large (̃1000) space/mark ratio the auxiliary RC-circuit is connected to the large capacitor directly. The calculation of both quasistable state durations is given and useful design relationships are established. An example of the multivibrator for different (9, 99 and 999) space/mark ratios is given.
Power conversion and control with zero AC current harmonics by means of a time-variable transformer
- Author(s): S. Singer
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 147 –150
- DOI: 10.1049/ip-g-1.1984.0030
- Type: Article
- + Show details - Hide details
-
p.
147
–150
(4)
A new unified approach to the synthesis of bidirectional (AC ↔ DC) power conversion and control is presented, in which, in contrast to conventional methods, zero current harmonics are created at the AC source. The desired conversion is achieved by coupling a load that includes an electromotive force to an AC source by means of a time-variable transformer (TVT). The transfer ratio of the TVT is controlled such that the equivalent load is viewed by the AC source as a linear impedance; consequently, the current waveform is not distorted. It is also possible to operate this system in a capacitive mode in order to improve the power factor, even if the load does not include capacitance.
New method for generating two-variable VSHPs and its application in the design of two-dimensional recursive digital filters with prescribed magnitude and constant group delay responses
- Author(s): M. Ahmadi and V. Ramachandran
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 151 –155
- DOI: 10.1049/ip-g-1.1984.0031
- Type: Article
- + Show details - Hide details
-
p.
151
–155
(5)
In the paper a method is presented for the design of 2-D stable recursive digital filters satisfying prescribed magnitude and constant group delay responses. This technique uses the properties of positive definite matrices and their application in generating 2-variable Very Strictly Hurwitz Polynomials (VSHPs), which will be assigned to the denominator of a 2-D analogue reference filter. Bilinear transformations are then applied to the transfer function of the derived 2-D analogue reference filter to obtain the discrete version of the 2-D filter. Parameters of the discrete 2-D filter can be used as the variables of optimisation to minimise the leastmean-square error between the desired and designed magnitude and group delay responses of the filter. To show the usefulness of the technique, an example is given.
Direct synthesis of filter transfer functions
- Author(s): V.D. Pavlović
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 156 –160
- DOI: 10.1049/ip-g-1.1984.0032
- Type: Article
- + Show details - Hide details
-
p.
156
–160
(5)
In this paper we propose a new procedure for the direct synthesis of complex transfer functions for a new class of selective filter. Conditional mean square approximation with Cheby̅shev weights, with three Lagrangian multipliers (for transfer-function values at cutoff frequency, at the origin (ω = 0) and for the phase at the cutoff frequency) gives a new class of filter derived in explicit form. By the choice of the transfer-function phase we can control the shape of amplitude characteristic in the passband or the filter selectivity.
Phase modulator with low nonlinear distortion
- Author(s): M.R. Temerinac and A.S. Marinčić
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 161 –170
- DOI: 10.1049/ip-g-1.1984.0033
- Type: Article
- + Show details - Hide details
-
p.
161
–170
(10)
In the paper results of an investigation of a phase modulator with linear segmental approximation of the trigonometric functions are given. Specific features of this modulator are high stability of the carrier frequency, large baseband bandwidth, and very low nonlinear distortion for maximum phase deviation of 90° or 180°. The investigation included computer simulations and experiments with the prototype modulator. The influence of the nonlinearity of the diode characteristics, of the temperature variation, and of the maximum phase deviation-variation is examined. In addition, procedures for the maximum phase deviation enhancement and for the optimisation of the modulator elements for given signal statistics are described.
Electrical network analogue for determining the optimal flows in multiterminal communication networks
- Author(s): B.V. Odintsov and A.C. Davies
- Source: IEE Proceedings G (Electronic Circuits and Systems), Volume 131, Issue 4, p. 171 –175
- DOI: 10.1049/ip-g-1.1984.0034
- Type: Article
- + Show details - Hide details
-
p.
171
–175
(5)
An electrical network model of a multiterminal communication network is described which can be used as a special-purpose analogue computer to determine the optimal distribution of information flow. It provides an alternative to digital-computer methods for which the computation time increases very rapidly with increasing network complexity, and which are therefore impractical for large networks.
Most viewed content for this Journal
Article
content/journals/ip-g-1
Journal
5
Most cited content for this Journal
We currently have no most cited data available for this content.
