Polarising circuit for several piezoelectric components - uses one component to control oscillator frequency which changes on reaching Curie temp.

摘要

The polarising circuit is used for several piezoelectric ceramic components. It applies a polarising voltage to the components whilst simultaneously heating them to their Curie temperatures. One of the components is used to control the frequency of an oscillator. The oscillator frequency changes suddenly when the Curie temp. is reached and thereby indicates that this temp. has been reached. The component acts as a capacitor in the resonant circuit of the oscillator.