| 摘要 |
PURPOSE:To simplify circuit constitution by eliminating the need for a matching transformer and its relating circuits by adjusting resonance impledance value of a sealed case, wherein one electrostrictive oscillator is sealed, at different frequencies to the same value. CONSTITUTION:An electrostrictive oscillator 1 is applied with two kinds of oscillation voltages from coated lead wires 5 and 4 alternately to perform thickness-directional oscillation at a 200kHz high frequency and diameter-directional oscillation at a 50kHz low frequlency. The wave transmitting side plate 8 of an insulating case 7 resonates by being applied with sound pressure based upon said two kinds of oscillation, but differs in resonance impedance according to its thickness (t). The resonance impedance of the wave transmitting side plate 8 which senses the high frequency oscillation and low frequency oscillation of the electrostrictive oscillator 1 is equalized by selecting the thickness (t). |
