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Voltage-controlled filter

About: Voltage-controlled filter is a research topic. Over the lifetime, 5514 publications have been published within this topic receiving 70872 citations. The topic is also known as: VCF.


Papers
More filters
Journal ArticleDOI
TL;DR: A new current-mode multifunction filter with a single input and three outputs employing only three positive type CCIIs and five passive elements is presented, realising three filter functions simultaneously all at high impedance outputs.
Abstract: A new current-mode multifunction filter with a single input and three outputs employing only three positive type CCIIs and five passive elements is presented. The proposed filter realises three filter functions simultaneously all at high impedance outputs. No component matching is required and all passive sensitivities are low.

44 citations

Journal ArticleDOI
TL;DR: It is shown that the designed sliding-mode mean-square filter generates the mean- square estimate, which has the same minimum estimation-error variance as the best estimate given by the classical Kalman-Bucy filter, although the gain matrices of both filters are different.
Abstract: This paper addresses the mean-square and mean-module filtering problems for a linear system with Gaussian white noises. The obtained solutions contain a sliding-mode term, signum of the innovation process. It is shown that the designed sliding-mode mean-square filter generates the mean-square estimate, which has the same minimum estimation-error variance as the best estimate given by the classical Kalman-Bucy filter, although the gain matrices of both filters are different. The designed sliding-mode mean-module filter generates the mean-module estimate, which yields a better value of the mean-module criterion in comparison with the mean-square Kalman-Bucy filter. The theoretical result is complemented with an illustrative example verifying the performance of the designed filters. It is demonstrated that the estimates produced by the designed sliding-mode mean-square filter and the Kalman-Bucy filter yield the same estimation-error variance, and there is an advantage in favor of the designed sliding-mode mean-module filter.

44 citations

Patent
01 Feb 1994
TL;DR: In this article, a speaker amplification system incorporates an adaptable notch filter that can dynamically adapt to the frequency of feedback oscillations caused by acoustic feedback frequency in order to remove the feedback oscillation before they are amplified above an audible level.
Abstract: A speaker amplification system incorporates an adaptable notch filter that can dynamically adapt to the frequency of feedback oscillations caused by acoustic feedback frequency in order to remove the feedback oscillation before they are amplified above an audible level. The adaptable notch filter is implemented as an adaptable finite impulse response filter by means of a digital signal processor. The finite impulse response filter also has an adaptable convergence factor which minimizes noise introduced by the filter. A special limiting routine is used to limit the values of the finite impulse response filter coefficients to prevent the filter from "blowing up" due to large input signal disturbances. The speaker amplification system also includes circuitry which provides multiple bands of equalization, with each band being capable of amplification. The mullet-band equalizer function allows hearing impaired people to adjust the frequency response of the telephones handset speaker, to provide better intelligibility, due to a large increase in volume over normal telephone handset receivers.

44 citations

Journal ArticleDOI
TL;DR: The authors show how analytical synthesis can be used to produce filter circuits that have less active elements than those recently reported voltage-mode structures which are based on differential-input OTAs.
Abstract: Despite the wealth of literature on operational transconductance amplifier (OTA)-C filters, the synthesis of high-order filter characteristics is still an active topic. In this paper the realization of voltage transfer functions based on canonical current-mode follow-the-leader-feedback (FLF) OTA-C structures are investigated. Two new structures are presented, which use only single-ended-input OTAs and grounded capacitors. The first structure has a single voltage input and multiple voltage outputs taken from different nodes, which enables it to provide simultaneous outputs of different filter functions. The second structure has a single voltage output and single voltage input distributed to different circuit nodes for a universal realization. The authors not only propose such filter structures, but also show how analytical synthesis can be used to produce filter circuits that have less active elements than those recently reported voltage-mode structures which are based on differential-input OTAs. This represents another attractive feature from chip area, and power consumption point of view. Simulation results verifying the theoretical analysis of the proposed filter structure are included.

44 citations

Patent
11 May 2005
TL;DR: In this article, a filter monitoring system employs a differential pressure sensor to provide a continuous signal output proportional to a pressure drop across a filter element, which communicates with a controller that provides output signals to indicate that the filter requires replacement and provides advanced warning for when the filter element will reach a predicted filter differential pressure limit value.
Abstract: A filter monitoring system employs a differential pressure sensor to provide a continuous signal output proportional to a pressure drop across a filter element. The differential pressure sensor communicates with a controller that provides output signals to indicate that the filter requires replacement and provides advanced warning for when the filter element will reach a predicted filter differential pressure limit value.

44 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239
202229
20201
20188
2017150
2016199