Cage-rotor induction machine axial leakage flux detection by parametric oscillation transducer

When a reactance parameter of a resonance circuit is varied periodically, under appropriate conditions, an oscillation will occur. Then, by having a measured variable change, the value of the erstwhile constant reactance parameter, the oscillation voltage is modulated. Subsequent demodulation gives a signal proportional to the measured variable. In this paper we shall explain the basic principles of parametric oscillation in RLC and the application in realizing a transducer suitable for the sensing of the axial leakage flux of the induction motor