Convert the square wave of output of H-bridge based on IR2110 to sinus wave

[ultrasonic]

Dear friends,

I've nearly finished my ultrasonic cleaner project. I've tried to drive 60W transducer with square wave from H-bridge based on IR2110 and PWM, but I think sinus wave will be much more efficient for this operation. So how can I convert my square wave to sinus wave with a basic way?

with kind regards,

 

[tolits2222]

try this link i hope it can help you...... thank you

 

[ALERTLINKS]

First determine the resonant frequency of transducer. Make the circuit resonant using capacitor in paralell to output coil.
Have a look a driver project,
Power ultrasonic driver

 

[ultrasonic]

First determine the resonant frequency of transducer. Make the circuit resonant using capacitor in paralell to output coil.
Have a look a driver project,
Power ultrasonic driver

Dear ALERLINKS,

Actually my problem is I couldnt get enough cavitation in ultrasonic machine. So I suspect from my driver circuit that produces square wave with H-bridge PWM. But when I looked the link you shared, high voltage square wave is used to drive ultrasonic transducer. I think the problem may be not to match resonant circuit to the transducer. here is my last schematic for driving transducer..

**broken link removed**


How can I determine the Capacitor value added to the transducer? ıs there anything to add this circuit such as L? One more thing, in some samples based on bjt transistors, snubber circuit is used. Do I have to add a snubber circuit too?

with kind regards,

 

[ALERTLINKS]

Snubber circuits are to protect switching devices. Oscillator frequency should be tweeked to resonant frequency, for this you have to make it variable and adjust for maximum output with load applied as resonant frequency change with load.
Avoid standing waves in wiring.A coil in series will convert square to sine wave and a paralell will make it resonant.
Here is a discussion about similar concern.
https://www.edaboard.com/threads/213634/.
CR4 - Thread: Ultrasonic Power Transducer Driver for Ultrasonic Cleaning
Intersting patented documents.

 

[ultrasonic]

I append piezo transducer impedance diagrams from a Valvo/Philips application book (in German). I would expect, that your impedance analyzer software supports a similar plot.

Transformer inductance can be utilized for impedance matching, of course. But you should consider, that it has both series (leak) inductance and parallel (main) inductance. With an ungapped core transformer, I would expect the series inductance to be the dominant component.

So I need to add a series inductance to the transducer. How can I determine its value? Do I have to add a capacitor, too?

 

[ALERTLINKS]

http://www.prolifictec.com/filehost/Sonar_front_end_sketch_rev01.pdf

In these circuits, transformer alse provide serial inductance and a coil in paralell to transducer peaks the voltages. These are simple and practical circuit od ultrasonic cleaners available in market.
You shoud have sufficent drive current for obtaining good response.
The maximum mechanical output is at electrical resonance frequency