Fogger/Fountain

[HarveyH42]

Just built a quick project. Kind of weird, but was searching through some junk boxes, and the parts just sort of lined up. Found a large clear plastic dome (thought they were smaller, for something else I'm working on), decided it was much too big. Then I found an ultrasonic fogger unit salvaged from a humidifier. So I got a little side-tracked, and took it apart, just to see. Put longer wires on the transducer and sense wire, drill a large hole in the plastic dome, hot glued it all together. Used one of the dog's bowls for a base. It fogs up pretty good, but there is sort of a fountain jet above the transducer. Need to put something over it sometime so it doesn't splatter on the sides. Had a RGB LED circuit still on a breadboard, so shoved it underneath in the dog bowl. Have to double up on the LEDs, but looks good for just an hour worth of work.

 

[Marks256]

Well done!

 

[Sceadwian]

Just use a little more water and the fountain will go away.

 

[HarveyH42]

Will give it another gallon of water and see what happens after work. Was a little concerned about how well the hot glue would hold up. The bowl I'm using as a base holds about a gallon... Live dangerously... No leaks so far, but the transducer does warm the water, and vibrates violently.

 

[Sceadwian]

I wouldn't use hot glue for a water seal, not to reliable, should probably use silicone sealant.

 

[Marks256]

Use some ThumGum. I love that stuff! It is water proof (as it is used to seal holes outside of homes for pluming). You should be able to get it for fairly cheap at a local hardware store.

 

[HarveyH42]

Added water, but no decrease in the foutain effect. At about 7 inches the amount of fog was seriously reduced. Figure I'll find/build some sort of deflector for the foutain to contain it. Thought about a pewter figurine at first, but the ones I make are mostly lead (closer to solder in composition...). Lead desolves in warm water, and breathing lead infused fog can't be good...

Yeah, hot glue was handy. Didn't really plan this out, it just sort of happened quickly on a sunday afternoon. Mostly just wanted to see how the fogger looked. Will likely put this on the shelf fo a while, and get back to my other project.

 

[Andy1845c]

Looks cool. Now you'll be all ready for next halloween

 

[things]

microwave fogger????

for some reason when you tip those foggers on their side under water in a plasic bowl the spot of the bowl where the fogger jet hits gets very hot and sometimes melts. i consider it an underwater microwave is it? just on a smaller scale and slightly different frequency?

 

[HarveyH42]

Actually its ultrasonic through a piezo transducer. I don't know if its the piezo that gets hot, or the water and friction. The heatsink on the driver mosfet got hot enough to melt the plastic box I put the power supply and driver boadr in to keep it dry. Haven't played with it since I noticed the damage, need to do some heat management badly.

 

[Sceadwian]

It's not vaporization, it's atomization. Big difference. It's basically a solid state nebulizer. The fact that the fet gets hot can be attributed to the high switching frequency (lots of linear loss) and the relativly high power.

 

[things]

what i mean is that when you put the fogger up so it makes fog instead if you lay the fogger on it's side in a plasic bowl the area of the bowl where the foggers jet hits gets hot verry quickly and melts sometimes

 

[HarveyH42]

I never ran it long enough for the water to get more then warm. Yes, I know its not vaporizing the water, doesn't get that hot. I'm guessing, but I'm thinking that THINGS melting observation is friction. The piezo can send a jet of water about 8 inches, and the frequency is very high.