Temp. compensated short circuit ring transducer evaluation circuit - uses measurement range with phase angles giving null drift

The temp. compensated evaluation circuit measures variations in impedances of short circuit ring transducers. The normally positive temp. characteristic is compensated over a defined measurement range. This has previously only been possible using semidifferential transducers. The circuit contains an oscillator (O) followed by a frequency divider (T) of at least seven stages, a low pass filter (TP), a current source (5) and a sample-and-hold circuit (23). The circuit is partic. easy to understand and can be easily simulated on a computer. This greatly facilitates circuit design. The variations arising in the oscillator frequency cannot affect the phase angle and hence do not lead to measurement errors. The temp. drift has a null point for phase angles between 90 and 120 degrees according to computer simulations. A.MONTAGE D'ANALYSE A COMPENSATION DE TEMPERATURE.B.LE MONTAGE COMPORTE UN OSCILLATEUR O, UN DIVISEUR DE FREQUENCE T D'AU MOINS SEPT ETAGES 1 A 8 COUPLE EN AVAL, UNE SOURCE D'INTENSITE S ET UN MONTAGE DU TYPE SAMPLE-AND-HOLDECHANTILONNER ET CONSERVER 23.C.L'INVENTION S'APPLIQUE NOTAMMENT A LA CONSTRUCTION AUTOMOBILE.