Results 301 to 310 of about 5,869,378 (346)
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Proceedings of the IRE, 1935
A system is described for electronic control of the local oscillator frequency in a superheterodyne receiver for the purpose of centering the signal carrier in the intermediate-frequency band in spite of inaccuracies of manual tuning and oscillator drift.
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A system is described for electronic control of the local oscillator frequency in a superheterodyne receiver for the purpose of centering the signal carrier in the intermediate-frequency band in spite of inaccuracies of manual tuning and oscillator drift.
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Radio-Frequency System. Part II—Frequency Control
Review of Scientific Instruments, 1953Frequency control in the Cosmotron is based on a signal derived from a pickup loop in the magnet gap. This signal is integrated electronically and is then distorted in a nonlinear network to yield a control voltage for the saturable-core oscillator. System constants are chosen such that the oscillator frequency has, at all times, the value associated ...
J. P. Blewett +2 more
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Optimal Frequency Controller Parameters of Wind Turbines Participating System Frequency Control
2018 IEEE Power & Energy Society General Meeting (PESGM), 2018Control of variable speed wind turbines to participate system frequency control has become a new requirement for wind turbines in a high penetrated wind farm power system. This paper focuses on selection of the frequency controller parameters of the wind turbines to improve the frequency control effect.
Guoyi Xu +4 more
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Resonant lines for frequency control
Electrical Engineering, 1935Vacuum tube oscillators for radio frequency signals above 25 megacycles may be controlled with a high degree of precision by resonant lines, and at lower frequencies may be used to obtain a larger power output than is obtainable from crystal oscillators.
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World Pumps, 2017
During oil transportation by pipeline, changes in the combination of pumps are often required. Recently, the focus has been on minimizing energy consumption costs. This paper looks at some indirect methods to control the frequency of pump switches.
Yang Yu, Changchun Wu, Jie Chen
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During oil transportation by pipeline, changes in the combination of pumps are often required. Recently, the focus has been on minimizing energy consumption costs. This paper looks at some indirect methods to control the frequency of pump switches.
Yang Yu, Changchun Wu, Jie Chen
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A controlled-frequency oscillator with frequency "memory"
Journal of Scientific Instruments, 1953An oscillator is described, which is made to follow the frequency of a pilot-source by means of an electronic servo-loop. When, at a given time t0, the oscillator is cut from its pilot-generator, it remains oscillating on the frequency the latter had at t0.
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Statistical process control for frequency control
44th Annual Symposium on Frequency Control, 2002Some possibilities of using statistical process control (SPC) tools to improve the accuracy, precision and quality of frequency control are discussed. The tools presented are process flow charts, Pareto charts, cause and effect charts, histograms, scatter diagrams/regression, control charts and experiments in the control of frequency standard processes.
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1994
The following class of time-invariant, linear, single-input single-output systems is considered \[ {\textstyle {\bigl({d\over dt}\bigr)y(t)= k\bigl({d\over dt}\bigr)u(t)+ m\bigl({d\over dt}\bigr)f(t)}}, \] where \(d(\cdot)\), \(k(\cdot)\), and \(m(\cdot)\) are polynomials with real coefficients and \({d\over dt}\) denotes the usual differential ...
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The following class of time-invariant, linear, single-input single-output systems is considered \[ {\textstyle {\bigl({d\over dt}\bigr)y(t)= k\bigl({d\over dt}\bigr)u(t)+ m\bigl({d\over dt}\bigr)f(t)}}, \] where \(d(\cdot)\), \(k(\cdot)\), and \(m(\cdot)\) are polynomials with real coefficients and \({d\over dt}\) denotes the usual differential ...
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Cervical cancer prevention and control in women living with human immunodeficiency virus
Ca-A Cancer Journal for Clinicians, 2021Philip E Castle, Vikrant V Sahasrabuddhe
exaly