Ultrasonic Transducer Driver Amplifiers
PDF Design of the power amplifier for ultrasonic transducer excitation is presented. Due to the clamping effect of C0 the amplifier driving. Efficiency is.
Power ultrasonic driver (14/05/11) 28/02/18: Check out on trying to make an ultrasonic knife from an ultrasonic cleaner! 25/03/17: I was able to measure the peak-to-peak displacement of the horn at resonance (about 20 microns) - see bottom of page.
21/02/17: I've finally done a video about the whole transducer measurement and tuning process - see the bottom of this page. 30/11/16: Kevin at the YouTube channel TheBackyardScientist has of using an ultrasonic cleaner to sonicate champagne and other fizzy drinks!
09/11/15: is attempting to produce ammonia by using a sort of 'ultrasound-assisted' Haber process. Well worth a read!
Important note (11/10/12) The circuit described here (i.e., a voltage-fed inverter connected directly to an ultrasonic transducer) will probably be happy driving low-powered transducers, below about 100W. However, as I've read more about ultrasonic transducers and driving circuits, I've realised that there are problems using this circuit for higher powers. The proper electrical model for an ultrasonic transducer is a capacitance in parallel with an LCR series resonant circuit. The fixed capacitance corresponds simply to the electrical capacitance of the transducer, neglecting mechanical oscillation effects. The LCR circuit corresponds to the resonant behaviour of the transducer.
Therefore, if the transducer is connected directly to the output of a voltage-fed inverter, the bridge transistors will charge and discharge the fixed capacitance, resulting in large current spikes at the switching transitions. For small transducers, this isn't really a problem because the transistors can handle the spikes, but it becomes a problem for larger transducers. To get around this problem, you need to use a matching network to adapt the electrical properties of the transducer to something that the inverter is happy driving. Matching networks come in many different forms, but the most common are LC and LLCC. Do a Google search on them and you should find some useful results.
Suppliers (23/01/13) Some interesting suppliers of ultrasonic transducers and related equipment: • Steiner & Martin () • Cangxin Science & Technology Electron Co. () • Sanho-Potent (Hong Kong) Ltd. () • UltrasonicsWorld () • MP Interconsulting () • Beijing Ultrasonic () Introduction On this page, I describe the construction of a power supply for a 70W ultrasonic tank transducer, and the machining & tuning of an aluminium horn. Adaptive filter theory by simon haykin pdf file. I originally started all this in order to do, but could find no simple, cheap means of driving high-power transducers. 'Proper' ultrasonic horns are usually made from titanium, and the power sources are usually fancy affairs with auto frequency tuning.
However, I found that, for the power levels I'm interested in, an aluminium horn works perfectly well, and it is possible to drive the transducer with a manually-controlled oscillator and inverter. I won't go into too much detail on the principles behind piezoelectricity and these kind of ultrasonic transducers - I assume you know a bit of background since you're reading this.
I'm using a 28kHz, 70W bolt-clamped Langevin transducer (part number SMBLTD45F28H) which was bough from Steiner & Martin () a few years ago for around $30-$40. For photos of it please scroll down or see their website. These are typically intended for ultrasonic cleaning, sonochemistry, low-power welding etc.