I would like to make a ultraonic type piezo mist generator which I can control (or change) the output mist rate.
For that I bought a Grove Water Atomizer to test.
I can generate the mist, but the output mist rate is rather low. By checking with an oscilloscope, I know this atomizer is driving 105KHz with about +40V to -20V.
The first question is how can I change the output mist rate? Can I do so by changing the driving voltage?
The second question is I think this atomizer output mist rate is very low, is there another similar module that can output a higher mist rate? Or is there a reference circuit that I can build myself to do so?
It says RIGHT THERE IN THE SPECS that maximum voltage is 65 volts. You're presently running at 60 volts. You could probably increase the voltage to, say, 100 volts. That would probably give you one big, but final, spurt of water which would be useful in putting out the subsequent fire.
Seriously, it just sounds like the device is doing all it can, or ever will.
If you consider the total number of "mist" particles produced per second as the "output mist rate" then it is directly dependent on the output power at the piezo surface.
Instead of increasing the power output from a single transducer, please consider using several transducers in parallel.
But if you want a "thick fog" (output mist rate= higher density of mist) you need to look elsewhere (water atomizers are tricky because of high surface tension of water and subsequent evaporation)- piezo mist producers are useful in labs where we want "uniform particle size"- but the amount of mist will be small.
I am not complaining this antomizer, I know it meet the spec., To clarify the two questions:
1. How can I control the mist rate dynamically for a general ultrasonic type piezo mist generator (not necessarily the Grave Water Antomizer).
2. I want to find another mist generator module that can generatre higher mist rate, or a reference circukt that I can build myself to generate more mist.
Consider a liquid flowing through a pipe and you are holding and shaking the free (open) end. The liquid that comes out will be broken into many small drops.
The decision about what to make is entirely yours. Find out different ways to make a nebulizer and also your definitive requirements.