Relaxation oscillator

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

Quartz-controlled transistor oscillator

Abstract: A QUARTZ CONTROLLED TRANSISTOR OSCILLATOR USABLE FOR TRANSMITTING AND RECEIVING CONVERTERS OF DIRECTIONAL RADIO SYSTEMS OPERATING IN THE GIGAHERTZ RANGE WHEREIN A BRIDGE CIRCUIT CONTAINING THE QUARTZ CRYSTAL IS IN CIRCUIT BETWEEN TWO TRANSISTORS, AND A FEEDBACK PATH BETWEEN THE TRANSISTORS INCLUDES A NETWORK SHIFTING THE PHASE IN DEPENDENCE ON THE OSCILLATING FREQUENCY OF THE QUARTZ.

Comment on `Discussion on Barkhausen and Nyquist stability criteria'

Abstract: This comment is related to the recently published article entitled "On `Discussion on Barkhausen and Nyquist stability criteria', Analog Integrated circuits and signal processing, Vol. 70, pp. 443---449, 2012. In this article the authors considered one of the possible four alternatives of the Wien-bridge oscillator that was previously considered in the article entitled "Discussion on Barkhausen and Nyquist stability criteria", Analog Integrated Circuits and Signal Processing, Vol. 62, pp. 327---332, 2010, which depicts the failure of Barkhausen criterion concerning the determination of the condition of oscillation startup of sinusoidal oscillation. In the above mentioned articles the operational amplifier used is assumed ideal. In this comment it will be shown that the Wien-bridge oscillator circuit used in the above mentioned articles can behave as a sinusoidal oscillator only at relatively high frequencies when the operational amplifier can be considered non-ideal. At relatively low frequencies; when the operational amplifier can be considered ideal, the same circuit behaves as a relaxation oscillator with a square wave output rather than a sinusoidal output.