Re: What happen when ultrasonic mist generator without water immersion
Recently my wife bought a mist generator and I first used it yesterday and used it again today.
The transducer motion is limited by water. Without water the transducer moves too much and will probably fracture.
A mist generator product senses a low water level and shuts off.
Re: What happen when ultrasonic mist generator without water immersion
So it is broken by the excessive movement? Or in the other words it is a mechanical damage?
If I lower the supply power to the transducer, can it be avoided?
Re: What happen when ultrasonic mist generator without water immersion
Of course reducing the power to the piezo will reduce its amount of flexing but how much? Maybe the datasheet has a maximum allowed power in a fluid and another reduced maximum allowed power in air.
Without a load, for the same power, the transducer MAY have a large excursion that MAY cause damage to the transducer itself.
Usually the real transducer body (a thin PZT material, usually) is pasted or soldered to another metal body that has sufficient mass to act as a load. Under such conditions, the input power MAY be dissipated in the glue or solder and it MAY come off.
Perhaps it is a 40W element and it can work for a few seconds without any damage - you can feel the rise in temp if there is no water present. The water also acts as a coolant for the transducer.
Re: What happen when ultrasonic mist generator without water immersion
The mist generator has a sensor above the disc level that shuts it off when water level reaches that 'arch' that looks like wrapped in shrink tubing.
How does it sense the presence of water is a mystery to me. I wish I knew.
-That level sensor does not work with gasoline- It does never turn on.
Of course I do not know about the specific one, but most water level sensors are based on conductivity. Even the most purified water you can get will be rather conducting and gasoline (paraffin) is one of the least conducting materials.