bolted langevin transducer

[xeratule]

Hi all,

Is there anyone who designed ultrasonic cleaning transducer (bolted langevin transducer)? Could you suggest me how to adjust it's resonance frequency. I do the calculations using L=c/2f and adjust the length of the transducer to the frequency I try to work. But when I measure (sweep) the transducer impedance (Z) vs frequency with the impedance analyzer I see the minimum impedance frequency (which also should be the series resonance frequency where vibration should be most powerful) is far away from the point I try to operate.

Thanks in advance.

 

[engineer1000]

Hi,
What are you using to drive the transducer, sine wave square wave? are you using a half bridge driver? I assume you are using a resonasnt cct using the static C of the transducer. In which case the formula is 1/(2*pI*F)2 C =L. Your transducer will be designed for a specific frequency i.e the ceramic disc should resonate in harmony with its mechanic resonance of the pillar. There will also be a number of resonant points above the stated frequency ( 3rd 5th harmonics)
Generally you will get a 40khz 50w transducer