Ultrasonic mist generator humidifier circuit. How to make an ultrasonic humidifier with your own hands
The ultrasonic gun is self-assembled on only two logical inverters and has a minimum number of components. Despite the ease of assembly, the design is quite powerful and can be used against drunk drunks, dogs or teenagers who sit up and sing in other people's porches.
Diagram of an ultrasonic gun
Chips CD4049 (HEF4049), CD4069, or domestic chips K561LN2, K176PU1, K176PU3, K561PU4 or any other standard logic chips with 6 or 4 logical inverters are suitable for the generator, but you have to change the pinout.
Our ultrasonic gun circuit is based on the HEF4049 chip. As already mentioned, we need to use only two logical inverters, and which of the six inverters to use is up to you.
The signal from the output of the last logic is amplified by transistors. To build up the last (power) transistor, in my case, two low-power KT315 transistors were used, but the choice is huge, you can put any NPN transistors of low and medium power.
The choice of a power switch is also not critical, you can install transistors from the KT815, KT817, KT819, KT805, KT829 series - the latter is composite and will work without an additional amplifier on low-power transistors. In order to increase the output power, powerful composite transistors such as KT827 can be used - but an additional amplifier will still be needed to build it up.
As a radiator, you can use any MF and HF heads with a power of 3-20 watts, you can also use piezo emitters from sirens (as in my case).
By selecting the capacitor and the resistance of the tuning resistor, the frequency is adjusted.
Such a self-assembled ultrasonic gun is quite suitable for protecting a summer cottage or a private house. But do not forget - the ultrasonic range is dangerous! We cannot hear it, but the body feels it. The fact is that the ears receive a signal, but the brain is not able to decode it, hence the reaction of our body.
Collect, test, rejoice - but be extremely careful, and I say goodbye to you, but not for long - AKA KASYAN.
Dry air in residential premises is an absolute discomfort and one of the root causes of poor health. But you should not rush into buying expensive equipment if you have the time and resources to make the simplest humidifier yourself, moreover, as a highly efficient compact device.
Difference from steam generator
Household humidifiers come in two types. Some work by increasing the evaporation area, others by heating the liquid to form steam. In both cases, the evaporation of water occurs naturally; today we will not talk about steam generators.
Most modern household appliances using a piezo emitter - a plate that vibrates at an ultrasonic frequency. The principle of evaporation here is as follows: water is broken into very small particles, a finely dispersed suspension, which cannot “stick together” back and continue to exist in the form of water vapor. The advantage of dispersed humidifiers is low energy consumption and the almost complete absence of scale in the device itself, which affects its durability.
Household ultrasonic humidifier
Hull details
The water tank is an ordinary three-liter jar. It will evaporate completely in 6-8 hours, if you need more, use five-liter bottles or cylinders for drinking water.
There are two types of connection of the container with the body. In our case, we will install the jar upside down on a round wooden washer. Of course, the service life of such a part is not too long, but nothing prevents you from making a new one. In addition, you can take a “moisture-resistant” tree as a basis, for example, larch or linden. First, we drill a washer from a 50 mm thick board with a 100 mm wood crown. Then, using the existing hole in the center with a 75 or 80 mm crown, we make an annular groove about 15 mm deep, and then select the central part with a 60 or 50 mm crown.
With a penknife, we expand the selection from the crown to 9-10 mm, then we pass inside with a thin chisel, giving the correct profile. As a result, the washer should fit tightly enough on the jar, like a lid. On the upper edge of the washer, we cut it with a hacksaw crosswise to a depth of about 15 mm, so that we get small holes for air suction and water outflow. As a result, the design should work as a drinker for young birds.
As a second option, you can use an external container: a small tank or canister connected to the evaporator with two thin silicone tubes. It is important, however, that the supply tube exits at the very bottom of the container. The level of insertion of the second hose exactly determines the height of the water layer.
ultrasonic evaporator
This is, in fact, the only expensive part that you have to buy. But do not rush to purchase components for existing models of air humidifiers, they are at least twice as expensive.
From 300 to 500 rubles is an ordinary piezoelectric element. You can buy this at online auctions, or directly from China. Make no mistake in choosing: a “bare” piezoelectric element will not work, you need a device in a waterproof case with a pair of outgoing wires and a plug at the end. The difference is that such a humidifier has all the necessary piping to generate the desired frequency and can be placed literally in any container with water without additional waterproofing.
The evaporator must be fixed at the bottom of the container in an arbitrary place, but not close to the walls, leaving free place to install a water tank. If the body of the evaporator is not watertight, or the plate does not sink deep enough during installation, the device can be fixed to the bottom of the container from the outside. It is necessary to make a neat hole under the side of the plate and seal the connection with sanitary silicone. For stability, the container will need to be equipped with legs or a stand.
Dry run protection
The emitter must always be immersed, this is critical. Without water, it resonates, heats up and fails in seconds.
Dry running protection can be performed with the simplest washer fluid level sensor for domestic cars. It is advisable to purchase short float sensors with a reed switch in a small tube, otherwise there is a high risk that the humidifier will turn off before the water in the jar runs out.
Install the sensor on the bottom of the container so that after the can is installed, it will be inside. If the container is separate, the sensor is installed in it. The normal mode of operation of the sensor is open contact, however, there may be several switching schemes. To invert the signal, use an intermediate relay or solid state switch. If the contact sensor has a standard scheme of operation, then it can be connected directly to the break in the power supply circuit of a low-power emitter.
Power and automation
Most piezo emitters are designed to be powered by a low voltage of 12 or 24 V. direct current. There are many options for how to power a homemade humidifier. We recommend, for safety reasons, to place the power supply and automation in a separate case.
The simplest and universal option- PC power supply. They have one system designations:
- yellow wires +12 V;
- black wire - common minus;
- dark blue wire - 12 V in reverse polarity (up to 0.5A).
Thus, the connection for 12 V is made with a black and yellow wire, and for 24 V - with yellow and blue.
Since a perfectly stabilized voltage is not required to power the emitter, small transformers from old radios and other household appliances With diode bridge and without a frequency generator. You can also wind the transformer yourself on a small (up to 30 mm) ferrite core, since the power of the piezo emitter is minimal.
To automate the operation of the evaporator to turn off when a certain level of humidity is reached, it will be necessary to assemble a small circuit by surface mounting. The first part is the DHT11 sensor with digital signal at the exit. The second element is the Arduino mini as a digital controller. The actuating device of the circuit is a thyristor key or a microrelay with a consumption current of up to 0.3 A, and a variable resistor of 10-15 kOhm acts as a regulator.
1. Power connectors. 2. Key transistors. 3. Fee Arduino controller. 4. Humidity sensor
The sketch (algorithm, firmware) for such an assembly is very simple. We declare two global int variables and write the values \u200b\u200bto them on the Pins of the sensor and potentiometer. To compare values, only one if-else construct is used in endless loop, the secondary condition of which is an exception that turns off the piezoelectric relay if the value of the variable humidity exceeds the setting value. To calibrate the values, use the port monitor of the connected card.
Final assembly of the device
Finally, let's assemble the device. We attract the washer under the jar to the bottom of the container with self-tapping screws, having previously smeared it with sealant. We put the empty jar in place, measure the indents from the sides and transfer the dimensions to the container lid. We cut a hole according to the marking and put a thin silicone tube cut along the edge on the edge.
With an indent of 20-30 mm from the cutout, we make a second hole with a diameter of 50 mm and install a computer cooler on four 60 mm screws, which will direct the air flow upwards, removing steam from the container and facilitating its generation with a slight vacuum. PVA 3x0.75 mm is used to connect to the power supply.
Now it remains to fill the jar with water to the brim, put the assembled humidifier on top, turn the structure over and apply power.
Greetings to lovers of buying abroad. A short review is devoted to an electric ultrasonic humidifier (fog generator) with an external power supply.
We recently moved into a new apartment. The old owners have increased the radiators and the temperature in the rooms is kept at 24-26 degrees. At this temperature, you have to constantly ventilate the room. But the air is still very dry. To increase the humidity of the air, an ultrasonic fog generator JAS 20 was recently purchased. I did not want to take ready-made models with a case, I did not like appearance and price. Yes, and I wanted to create my own unique piece of furniture.
Characteristics:
Material: most likely thin stainless steel
Emitter: ceramic, d 20 mm
Color: silver
Backlight: 12 LEDs. blue red and yellow color. They flash in all possible combinations in blocks formed by the same color.
Ceramic disc life: 5000 hours
Operating frequency: 1700±50KHz
Evaporation: 350 ml/hour
Working temperature: 5~45"C
Tank water level: 15mm~35mm
Low water protection: sticks out from the top in heat shrink
Food:
input AC 220~240V 50/60Hz
output AC 24 V
power 16 W
The plug is flat, the adapter is not included.
The packaging was a little damaged during transportation, there is no film with bubbles inside, but everything remained intact. Store photos do not match. Chinese lettering on the side simple circuit how to change the ceramic emitter. 
Group photo: 
Illuminated emitter: 
Dimensions: 
Power Supply: 
The emitter did not fit into the intended container (it was calculated at 4 cm, but it turned out to be 4.6). Therefore, the photo is in a three-liter jar. In the jar, at a water level of 7 cm, a layer of dense fog appears almost to the very top, and a fine haze rises above the neck. Less water was not poured, a lot of large splashes fly. You can't stick your finger into the water above the emitter - it hurts. I remembered ultrasonic washing machines, the work of which is not felt at all. The red and blue color of the backlight looks very impressive. 
Flaws:
The power supply gets very hot and smells bad. There is no normal switch, it is not very convenient to disconnect the plug. If the water level is low, splashes will fly out if the container is narrow. From the bottom of the emitter, the remnants are visible in a circle protective film, with which the bottom was covered, which means that it is at the junction of the bottom and the side wall, and over time it can collapse.
Conclusion:
The device performs its functions. Humidity in a small room will increase. Looks good. It is better to use distilled water for evaporation. Through a rubber stopper, the wire from the container can be led out through the hole. The plastic is of good quality, the wires are good. The ceramic emitter can be seen. A little tweak wouldn't hurt, of course. Replace the plug and install the switch.
Once again, looking through the vast expanses of Ali Express, I came across such a fogger.
I bought it .... just like that, for experiments. As it turned out, it is a working element, if not all, then most humidifiers, and it works very well. The principle of its operation is that the membrane vibrating with an ultrasonic frequency creates a vacuum. Water in a vacuum is known to go into a gaseous state at much lower temperatures.
In practice, the device is a cylinder, with a diameter of about three and a half centimeters and a height of about two and a half. It is powered by direct current, voltage 24 V. In its upper part there is a sensor (electrode) in order to prevent "dry running" - as soon as the water level drops below it, the device stops working. When the connected device is lowered into the water, it immediately starts working - a "fountain" of fog bubbles forms in the upper part. The water level in the container with the device is important - if it is more than two or three centimeters above it, fog will not form. The bubbles will have time to dissolve in the water and on the surface we will see only a small fountain. The water consumption is quite small. I used such a fogger when making a homemade firebox for a false fireplace. There it is located in a tank with a square section, measuring 30 by 18 cm. A two-centimeter water level is enough for about 4-5 hours of continuous operation. The cord has a rubber sealing plug that will allow you to seal the hole in the container through which you pass the cord.
The device can be used in in large numbers diverse homemade both practical (humidifiers) and decorative (fountains, "alpine hills", decorative ponds, and so on). At the same time, on Ali Express you will find a similar
You can ask it, for example, from computer block supply, from which you can easily remove the desired voltage. And you can buy a fogger on Ali Express immediately with a power supply. Such a set will cost you about 7 - 8 dollars.
And finally ... When designing homemade products with this device, do not forget that its "product" is not water vapor, but fog! It is heavier than air and creeps down. If the device works, for example, in a basin with water, then the basin will be filled with mist, then for some time it will become denser, and only then "pour out". True, you will not see the process of "pouring out" clearly - the upper stem will dissolve from contact with air ...
