Method and device for the digitization and linearization of a quasi-sinusoidal sensor.

摘要

The method involves the measurement of the variation ( DELTA phi x) in a signal ( phi x) received by the sensor using the following operations:
&cirf& Superimposing on the signal to be measured a first auxiliary periodic signal ( phi I) of frequency fI higher than the highest frequency in the spectrum of the signal to be measured and of amplitude more or less equal to PHI 0/2, and a second auxiliary signal consisting of a periodic linear ramp voltage ( phi R) of frequency fR very much lower than fI and of amplitude PHI 1, the sensor thus receiving a composite signal comprising the signal to be measured, the first auxiliary signal and the second auxiliary signal,
&cirf& Deriving from the signal delivered by the sensor two periodic signals, VC1 and VC2, of period PHI 0 and in quadrature,
&cirf& Measuring the level b of the second auxiliary signal when the signal VC1 reaches a predetermined state, this state having a periodicity PHI 1 in the signal VC1,
&cirf& Counting the number a of periods PHI 1 in which the signal to be measured varies as a function of the changes of state in the signals VC1 and VC2, the level of the second auxiliary signal being blocked during the said counting,
&cirf& Calculating the variation DELTA phi x of the signal to be measured according to the equation DELTA phi x = a PHI 1 + b, 0 </= b </= PHI 1.
<??>Application especially to Josephson effect magnetic sensors.
<IMAGE>