Fourier transform recorder system - for electric signal processed by spectral analyser and uses A=D converter with register, recording memory and timer circuit

摘要

The system records the Fourier transform of a signal applied at the input of a spectral analyser delivering on an output X a CRT sweep signal. The analyser delivers on an output Y the spectral amplitude function signal. The d signal from output X defines a peak. The Y output signal is applied to an analogue digital converter having an output register whose digital output is connected to a memory. The Y output signal is also applied to a comparator which triggers a timing circuit when the Y output is less than a predetermined voltage level. The timer circuit emits after timing an order signal for transfer from register to memory followed by register zero reset. The time constant of the timer circuit being less than the period between two peaks.