Relaxation oscillator

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

Comparator for use in astable multivibrator

Abstract: In a comparator circuit in which the active element is a long-tailed transistor pair the input bias current to at least one input of the pair is maintained constant by providing a supplemental current from a current source. A multivibrator incorporating the comparator is also described.

Improvements in or relating to electric rectangular-wave generator circuits, relaxation oscillator circuits, and monostable circuits

Abstract: 787,917 Transistor generating and single stable state circuits MULLARD RADIO VALVE CO, Ltd May 30, 1956 [May 27, 1955], No 15371/55 Class 40 (6) In a circuit comprising a first transistor T1 having an alpha less than unity, DC conducting impedances Re, Rc are connected in the emitter and collector leads with a regenerative feed-back loop providing a DC path between the collector and the base of a second transistor T2, a DC conductive coupling being provided between the two emitters The base of transistor T1 is coupled over a capacitor Cb to a fixed potential point and over a resistor Rb1 to a point of constant potential or to one which is constant during the triggered period With transistor T1 fully conducting, the collector potential approaches that of the emitter so that the potential across the emitter-base of transistor T2 is such as to maintain it near cut-off The potential-Eb is chosen sufficiently negative that the transistor T1 is fully conducting and a positive pulse applied at the base b1 or a negative pulse at point c1, e1 triggers the circuit to its opposite state Assuming a negative potential applied at collector c1, the base of transistor T2 is driven sufficiently negative for it to pass current so that the potentials of the emitters e2, e1 fall and the transistor T1 is driven to cut-off, since the base is held temporarily at constant potential due to capacitor Cb The capacitor Cb commences to discharge over resistor Rb1 and continues until the base potential of transistor T1 is lowered sufficiently for it to conduct again, whereupon the regenerative loop is effective to restore the circuit to its normal state In order to avoid the effect of hole storage, the collector c1 may be connected through a rectifier to an intermediate potential The resistor Rb1 may be returned to the emitter e2 which assumes a potential near the supply when transistor T2 is conducting, and such a circuit is useful for producing short pulses By suitable choice or resistors Rc, Rb1 it may be arranged that transistor T1 is-not saturated when in the conducting state so that the circuit has no stable state and is selfoscillatory If the potential-Eb is raised sufficiently, transistor T1 cuts off and transistor T2 is in the conducting state in the normal condition The circuit may be triggered by pulses of the opposite polarity from the former case, applied in the regenerative loop The capacitor Ce may be employed to enhance the feed-back action A resistor may be inserted between the collector or transistor T1 and the base of transistor T2 Specification 767,727 is referred to

Design and analysis of relaxation oscillators based on voltage-driven NICs

Abstract: This paper investigates the design and analysis of relaxation oscillators based on voltage-driven negative impedance converters. Results of Pspice simulations for submicron technologies are shown. In comparison to oscillators based on current-driven NICs, oscillators presented here have much higher operating frequencies.

Flueric pressure- and temperature-insensitive oscillator for timer application

Abstract: : Three fluid relaxation oscillators using R-C-R feedback loops were tested to establish the feedback resistances required to make the oscillator frequency insensitive to temperature and pressure. The frequency of the three oscillators, geometrically similar but with different feedback resistances, was measured as a function of stagnation pressure and temperature. With modifications guided by these data, one of the oscillators showed frequency variations of less than 2 percent with changes in input pressure of 6 to 30 psig and changes in temperature of 75 to 200F. A theoretical analysis indicates that an oscillator frequency simultaneously insensitive to temperature and pressure can be achieved using a lumped R-C-R network in the feedback loop.