How to control the driving frequency when working with high power ultrasonic transducers. When you reach the maximum you will have tuned your driver circuit.

Hi guys, I am probably in way over my head as usual but the enticement of learning something new is irresistible:twisted: I am trying to design a simple (well if that applies) 1000watt, 20Khz, ultrasonic driver. It will be powered from a standard 120Volt, 60 Hz american grid or 220V, 60 Hz power. It will be used for sonication of biodiesel for mixing and possibly separation of vegetable oil from Algae cells in the production of biodiesel. I would simply buy a unit but they cost on average of 10 to 20k american dollars or about half of my yearly job salary. The transducer will require a maximum voltage of 150 volts peak to peak. Eltex alatau puljt instrukciya.

I supposed I could find a transducer that would allow high voltages in order to lower the current requirement. The transformer I assume will be the more difficult part of this rather than the driver section of mosfets or IGBT driven by a high/low side driver chip.

Is there something out there I could study or is this project more complex and involved than average electronic skills require? I built a fairly high-power ultrasonic system for someone using an AVR and a driver circuit he gave me. I've still got the schematics and the PCB designs for the driver and AVR boards. I can't remember how much power it delivered but it was powered from +200V and -200V. The AVR generated the sine wave input using a software DDS. I think the frequency was about 25 kHz. It could be tuned to the exact frequency for maximum output power using up/down pushbuttons to control the frequency.

This sort of project is rather complex and would need quite a lot of experience. Letthesmokeout wrote: I am trying to design a simple (well if that applies) 1000watt, 20Khz, ultrasonic driver. It will be powered from a standard 120Volt, 60 Hz american grid or 220V, 60 Hz power. The transducer will require a maximum voltage of 150 volts peak to peak.

I supposed I could find a transducer that would allow high voltages in order to lower the current requirement. Is there something out there I could study or is this project more complex and involved than average electronic skills require?

Greetings Tad, Do you have the transducer? Plan to buy one? This is the key component, and it requires an electrical matching circuit to adapt the power from a driver to get good sonic energy out. Rather than re-inventing the wheel, why not visit a used equiment emporium or search eBay for a used but functional ultrasonic cleaner? You can remove the electronics and transducer for your project. Adjustment of the matching network may be necessary to suit the resonance of your tank (and viscosity of your fuel mix). Ultrasonic cleaners are used in industry, particularly the semiconductor and medical sectors, as well as smaller units for cleaning jewelery, etc.

Comments Welcome! Thanks for the input. I realize this will be a major project. I tend to go for projects that others think are literally impossible, or at least extremely difficult because of the challenge and the great learning possibilities. For instance.

A decade ago I didn't know what a microcontroller was. A friend of mine asked me to build him a processor controlled lighting system for pools whereby 6 incandescent lamps are phase controlled to control color mixtures of the different colored lamps.

I went and posted in a PIC forum and was promptly laughed out of there.:oops: 6 Months later I had built this system: It did give me many late nights and many headaches, but I learned a lot and found the impossible to not be so impossible. Keeping track of 6 lamps and their brightness all within each half wave was lots of fun! I would certainly buy a unit from ebay etc if it were less than $1500 American or so but I have a hard time finding anything resembling this amount of power output and most are simple 100 watt ultrasonic cleaning systems which don't do me much good. I have found other commercial items but the prices were in the 5000-8000 dollar range which unfortunately is out of my reach. Another friend of mine has since come up with a system for creating large amounts of vegetable oil from algae and needs some way of separating (bursting the algae cells) the oil from the cells.