| 摘要 |
Circuit arrangement for inducing oscillations in an ultrasonic transducer approximating its natural resonance frequency, and comprising an oscillator for generation of an excitation AC voltage. A pulse gate circuit is connected to supply pulse wise application of the AC voltage to the transducer. The oscillator frequency is controlled by an auxiliary pulse generator connected to the transducer in parallel with the oscillator. A gate circuit and a phase discriminator are employed to produce favorable excitation for the particular oscillation mode of the transducer. The transducer is made preferably from a piezo electric ceramic. The circuit includes means capable of automatically finding the resonance frequency of the transducer. |
