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Relaxation oscillator

About: Relaxation oscillator is a research topic. Over the lifetime, 1952 publications have been published within this topic receiving 22326 citations.


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Patent
Shouji Abou1, Keiko Chikaoka1
18 Oct 1985
TL;DR: In this article, a voltage controlled oscillator with at least one first capacitor is defined, where the oscillator receives first and second input voltages and charges the first capacitor with a first current corresponding to the first input voltage.
Abstract: A voltage controlled oscillator includes an oscillator having at least one first capacitor. The oscillator receives first and second input voltages and charges the first capacitor with a first current corresponding to the first input voltage. The oscillator oscillates at a frequency corresponding to the first and second input voltages. To remove the adverse influence on the oscillating frequency by the change of process parameters caused in the stage of manufacturing the voltage controlled oscillators, a second capacitor is charged for a predetermined period by a current corresponding to the first voltage. After the charging of the second capacitor ends, a sample/hold circuit samples and holds the charged voltage across the second capacitor. An operational amplifier receives, at its positive input terminal, the output voltage of the sample/hold circuit, and, at its negative input terminal, the reference voltage. The operational amplifier controls the first voltage so that the output signal of the sample/hold circuit will be equal to the reference voltage. Repeating the sequence of the charging, sampling and comparing operations eliminates the influence upon the oscillating frequency by the change of the process parameters caused in the manufacturing stage.

19 citations

Patent
02 Mar 2004
TL;DR: In this paper, an optical relaxation oscillator assembly, outcoupling optics, a photodetector and a controller are used to adjust the controllable repetition rate of a series of optical pulses.
Abstract: The laser range finding apparatus includes an optical relaxation oscillator assembly, outcoupling optics, a photodetector and a controller. The optical relaxation oscillator assembly produces relaxation oscillations. The relaxation oscillations are a series of optical pulses having a controllable repetition rate. The outcoupling optics receives the series of optical pulses and redirects a minor portion of the energy of the series of optical pulses. A major portion of the energy of the series of optical pulses is adjusted in accordance with first desired beam propagation parameters. A photodetector receives the minor portion and converts the minor portion to an electrical signal representative of the series of optical pulses. A controller receives the electrical signal and determines the repetition period between the optical pulses. The controller provides a controller output to the optical relaxation oscillator assembly for adjusting the controllable repetition rate of the series of optical pulses produced by the optical relaxation oscillator assembly. During operation, the major portion of the energy of the series of optical pulses is directed to a reflecting target, reflected therefrom, collected by the outcoupling optics, and directed back to the optical relaxation oscillator assembly to stimulate subsequent relaxation oscillations, thus locking the period of the relaxations oscillations to the time of flight of the roundtrip path between the laser finding apparatus and the reflecting target.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the authors considered two fundamental models of genetic circuits: smooth and relaxation oscillators and found that a period mismatch induces better entrainment in both types of oscillators; the enhancement occurs in the vicinity of the bifurcation on their limit cycles.
Abstract: Biological oscillators coordinate individual cellular components so that they function coherently and collectively. They are typically composed of multiple feedback loops, and period mismatch is unavoidable in biological implementations. We investigated the advantageous effect of this period mismatch in terms of a synchronization response to external stimuli. Specifically, we considered two fundamental models of genetic circuits: smooth and relaxation oscillators. Using phase reduction and Floquet multipliers, we numerically analysed their entrainability under different coupling strengths and period ratios. We found that a period mismatch induces better entrainment in both types of oscillator; the enhancement occurs in the vicinity of the bifurcation on their limit cycles. In the smooth oscillator, the optimal period ratio for the enhancement coincides with the experimentally observed ratio, which suggests biological exploitation of the period mismatch. Although the origin of multiple feedback loops is often explained as a passive mechanism to ensure robustness against perturbation, we study the active benefits of the period mismatch, which include increasing the efficiency of the genetic oscillators. Our findings show a qualitatively different perspective for both the inherent advantages of multiple loops and their essentiality.

19 citations

Patent
James Snider1, Glen Reeser1
09 Oct 1998
TL;DR: In this paper, a voltage controlled oscillator with two negative resistance generators (32, 34) is used to provide optimum frequency selectivity within each frequency band, and the VCO uses only one varactor to tune both frequency bands which reduces costs.
Abstract: A voltage controlled oscillator operable on two widely separated frequency bands, such as 900MHz and 1.8 GHz for example. The voltage controlled oscillator includes two negative resistance generators (32, 34) which share a common tunable tank circuit (26) and a common impedance matched combiner circuit (28) which provides the RF output (36). The VCO uses no pin diodes which could degrade Q and phase noise, and the VCO uses only one varactor (30) to tune both frequency bands which reduces costs. Separate negative resistance generators (32, 34) are used to provide optimum frequency selectivity within each frequency band.

19 citations

Patent
27 Oct 1995
TL;DR: In this article, a fly-back voltage regulator is used for providing AC power to an electroluminescent lamp powered by a battery, where a capacitor coupled to an inductor through a diode is charged by the repetitive charge and discharge of the inductor when the transistor is switched ON and OFF at high frequency by the high frequency oscillator.
Abstract: A circuit for providing AC power to an electroluminescent lamp powered by a battery comprises a high frequency oscillator through a control to drive a fly back voltage regulator comprising an inductor powered by a relatively low battery voltage and coupled to ground through a switching transistor. A capacitor coupled to the inductor through a diode is charged by the repetitive charge and discharge of the inductor when the transistor is switched ON and OFF at high frequency by the high frequency oscillator. The charge in the capacitor is dithered about a high DC voltage, such as 100 VDC, by sensing the charged voltage for periodically turning the transistor ON and OFF accordingly. A bridge circuit receives two pairs of like lower frequency square wave pulse signals of opposite polarity from a low frequency oscillator. Each signal is applied to a different one of two series connected legs of two opposite like branches, each branch coupled between the high DC voltage and ground, each leg containing two switching FET transistor and a current source. An electroluminescent lamp is connected between the legs in each branch. One of the legs in each branch is alternately turned ON and the other leg turned OFF by the square wave signals to provide the equivalent of an AC signal to the electroluminescent lamp in opposing directions, thereby doubling the value of the peak stepped up DC voltage.

19 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202322
202242
202128
202044
201962
201855