Agilent 1960-04 free download

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HEWLETT-PACKARD JOURNAL T E C H N I C A L I N F O R M A T I O N F R O M T H E - h p - L A B O R A T O R I E S Vol.11 No. 8-10 JBLISHED BY THE HEWLETT-PACKARD COMPANY, 1501 PAGE MILL ROAD, PALO ALTO, CALIFORNIA APR.-JUNE, 1960 The Effect of jut-Circuit Non-Linearity on the Amplitude Stability of RC Oscillators Ed. Note: In the RC oscillator the amplitude which the oscillator has exhibited an exag control element is presented in the following of oscillation is controlled by a thermally- gerated response to such disturbances (see article. We believe the analysis will be of sensitive resistance in the form of a small Fig. 2 below). In a few cases actual envelope general interest because it takes into ac tungsten lamp. This control element gives instability has been observed. Although this count the effect of the small non-linearity the oscillator its characteristic constancy of effect was generally attributed to tube that exists in the amplifier portion of the output level over a wide range of operating anomalies, since aging or replacing the oscillator circuit, where previous analyses conditions. In practice, for example, the os tubes removed the effect, over a period of have assumed an ideally linear amplifier. cillator's response is quite slight to such dis time the impression began to form that a The analysis shows that, if the amplifier were turbances as hum, microphonics, a change more definite factor was involved. in fact ideally linear, the envelope response with tuning in the impedance ratios in the frequency-determining network, or a change The envelope response was then investi to amplitude disturbances would be some in loading at the oscillator output. gated analytically by Bernard M. Oliver, JOO c/fa more than it is. It shows further that At the same time, and in contrast to the -hp- vice-president for R & D, and his analy the amplifier must have a slight compression great majority of cases, experience with the sis