Relaxation oscillator

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

Novel Schmitt trigger with wide temperature range

Abstract: A novel Schmitt trigger circuit, implemented by a reset-set (RS) trigger and two simple distinct inverters, is proposed. Its trigger levels are determined by two Complementary Metal-Oxide-Semiconductor (CMOS) inverters. Contrast with traditional six transistors Schmitt trigger, its temperature and supply voltage characteristics have been analyzed. These two triggers are applied into relaxation oscillator and the result shows that the proposed one in this paper has better performance over wide temperature range, whose temperature coefficient from 0 to 85 °C is 1/5 of the traditional one.

Improved electric fence installation

Abstract: 1,210,372 Charging and discharging capacitors H MULLER, [trading as HORIZONTGERATEWERK DR HEINZ MULLER] 18 Oct, 1967 [26 Oct, 1966], No 47381/67 Heading H2H An electric fence energizing circuit supplies periodic pulses to the fence and aperiod higher voltage pulses consequent on the fence being touched or displaced The periodic pulses may be developed in a relaxation oscillator comprising transistor 31 and the aperiodic pulses by a monostable circuit including transistors 44, 45, both circuits having a common output transistor 36 A capacitor 33 is charged through a resistor 34 firing transistor 31 which discharges capacitor 33 through resistors 35, K32, K36, conduction of transistor 31 also firing transistors 32, 36 which discharge a previously charged capacitor 37 through the primary winding of a transformer 40 A damped oscillation occurs in the fence wire on the re-opening of transistor 36 When an animal charges the fence, an impulse generator 6 delivers a pulse through transformer 43 to a transistor 44 which through transistor 45 fires transistor 36 again discharging capacitor 37 Resistor 46 is adjusted so that the discharge period of the capacitor 37 is longer than that set on resistor 35 The impulse generators 6 comprise a displaceable permanent magnet core in an inductor (Figs 7 and 9, not shown), the inductor being normally shortcircuited by contacts or a diode In another arrangement (Fig 5, not shown), the periodic pulses are provided by a first relay circuit and if the periodic oscillations are artificially damped by animal contact a second relay circuit supplies higher voltage pulses An arrangement is incorporated to limit the number of aperiodic pulses delivered in any period A circuit of the second type may be incorporated in Fig 6

Dangerous Aging Transition in a Network of Coupled Oscillators

Abstract: In this article, we investigate the dynamical robustness in a network of relaxation oscillators. In particular, we consider a network of diffusively coupled Van der Pol oscillators to explore the aging transition phenomena. Our investigation reveals that the mechanism of aging transition in a network of Van der Pol oscillator is quite different from that of typical sinusoidal oscillators such as Stuart-Landau oscillators. Unlike sinusoidal oscillators, the order parameter does not follow the second-order phase transition. Rather we observe an abnormal phase transition of the order parameter due to sudden unbounded trajectories at a critical point. We call it a dangerous aging transition. We provide details bifurcation analysis of such abnormal phase transition. We show that the boundary crisis of a limit-cycle oscillator is at the helm of such a dangerous aging transition.

A novel noncontact electromagnetic field-based sensor for the monitoring of resonant fatigue tests

Abstract: In this paper, a prototype of an electromagnetic field-based (EFB) vibration sensor that uses a novel sensing technique to monitor the resonant fatigue testing of a conductive and/or ferromagnetic target specimen is presented. The distance from the target to a coil within the sensor affects the impedance of the coil. The electronic circuitry for the sensor consists of a relaxation oscillator, an embedded microprocessor module and a high-speed digital-to-analog converter. The impedance of the coil determines the frequency of oscillation of the relaxation oscillator's output, so that vibration of the target causes changes in the oscillation frequency. A?timer in the embedded microprocessor module is used to count the oscillations, producing a digital signal that indicates the coil-to-target distance. The digital signal is instantaneously converted to an analog signal to produce the sensor's output. The key technologies proposed include: (1)?a novel timer counting method using the input capture functionality and timer of the embedded microprocessor module and (2)?significant simplification of the analog electronic circuitry. The performance of the proposed sensor has been verified using AISI 1095 carbon steel and Al6061?T6 aluminum alloy specimens during resonant fatigue tests. The sensor shows a good linearity between displacement amplitudes and output voltages.