Design formulas for biquad active filters using three operational amplifiers

Fleischer, P.E.; Tow, J.

doi:10.1109/proc.1973.9124

Cited by 36 publications

(12 citation statements)

References 3 publications

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“…Two identical Fleischer-Tow analog feedback controllers 25 were used in this research. The biquad circuit is a second-order filter whose response can be shaped by appropriate choices of resistor and capacitor values.…”

Section: Feedback Controllersmentioning

confidence: 99%

Active sound transmission control of a double-panel module using decoupled analog feedback control: Experimental results

Sagers

Leishman

Blotter

2010

The Journal of the Acoustical Society of America

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Low-frequency sound transmission through passive lightweight partitions often renders them ineffective as means of sound isolation. As a result, researchers have investigated actively controlled lightweight partitions in an effort to remedy this problem. One promising approach involves active segmented partitions (ASPs), in which partitions are segmented into several distinctly controlled modules. This paper provides an experimental analysis of a double-panel ASP module wherein the source- and transmitting-side panels are independently controlled by an analog feedback controller. Experimental results, including plant frequency response functions, acoustic coupling strengths, frequency response functions, and transmission losses (TLs) of single- and double-panel modules, are presented and compared to numerical predictions. Over the bandwidth of 20 Hz to 1 kHz, the average measured TL for an actively controlled single-panel module was 29 dB, compared to 14 dB for the passive case. The average measured TL over the same bandwidth for the actively controlled double-panel module was 57 dB, compared to 31 dB for the passive case.

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Section: Feedback Controllersmentioning

confidence: 99%

Active sound transmission control of a double-panel module using decoupled analog feedback control: Experimental results

Sagers

Leishman

Blotter

2010

The Journal of the Acoustical Society of America

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“…Two independent controllers whose complex FRFs are represented by H 1 and H 2 were used ͑one for each panel͒. For this work, the controllers were second-order, analog Fleischer-Tow biquad circuits, [20][21][22] which use resistors, capacitors, and operational amplifiers to create desired transfer functions between their input and output voltages. The shape of a transfer function is determined by choosing the values of the resistors and capacitors.…”

Section: B Active Control Descriptionmentioning

confidence: 99%

“…For the control circuit described earlier, the resistor and capacitor values were chosen to position the cutoff frequencies of the control filter and thus maximize attenuation while maintaining desired stability margins. [20][21][22] The selected values are given in Table II, and the frequency response of the resulting controller is shown in Fig. 6.…”

Section: A Predicted Plant Frfsmentioning

confidence: 99%

A double-panel active segmented partition module using decoupled analog feedback controllers: Numerical model

Sagers

Leishman

Blotter

2009

The Journal of the Acoustical Society of America

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Low-frequency sound transmission has long plagued the sound isolation performance of lightweight partitions. Over the past 2 decades, researchers have investigated actively controlled structures to prevent sound transmission from a source space into a receiving space. An approach using active segmented partitions (ASPs) seeks to improve low-frequency sound isolation capabilities. An ASP is a partition which has been mechanically and acoustically segmented into a number of small individually controlled modules. This paper provides a theoretical and numerical development of a single ASP module configuration, wherein each panel of the double-panel structure is independently actuated and controlled by an analog feedback controller. A numerical model is developed to estimate frequency response functions for the purpose of controller design, to understand the effects of acoustic coupling between the panels, to predict the transmission loss of the module in both passive and active states, and to demonstrate that the proposed ASP module will produce bidirectional sound isolation.

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“…Also, the simplicity of the voltage-controlled voltage source (VCVS) filter circuits are preferable (Moore et al 1976), but for their tuning it is necessary to control the parameters of a great number of resistors then in the biquads (Fleisher and Tow 1973). As a specific example, in the circuit (Fig.…”

Section: Nikolay Trifonov Tchamovtmentioning

confidence: 99%

Analogue elliptical filters with digital control and memory

Tchamov¹

1990

International Journal of Electronics

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Design formulas for biquad active filters using three operational amplifiers

Cited by 36 publications

References 3 publications

Active sound transmission control of a double-panel module using decoupled analog feedback control: Experimental results

Active sound transmission control of a double-panel module using decoupled analog feedback control: Experimental results

A double-panel active segmented partition module using decoupled analog feedback controllers: Numerical model

Analogue elliptical filters with digital control and memory

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