Hello friends! Today I'm going to talk about this device, which is called an ultrasonic levitron. Small pieces of styrofoam hang in the air without any strings. Let's try to understand this phenomenon. So, the human ear hears sound up to a frequency of 20kHz, something that is more than 20 kHz is also a sound, but people do not hear it. Some animals, such as bats, listen to it, but the human ear is not able to hear ultrasound. But my smartphone hears. So, we do not hear a sound with a frequency of more than 20 kHz, such a sound is called ultrasound. Ultrasound, like any sound, creates longitudinal waves in the medium and propagates in the air at a speed of 330 m/s. /Naturally, the waves can extinguish each other and add up and form standing waves in the air, resulting in antinodes and antiparticles. In the antinodes of the sound pressure, it is maximum in the minima. If a piece of foam gets into the abyss, then it is pushed out of it as it happens in the video. If a piece of styrofoam is placed in between the antinodes, in the minima, then it will start hanging there. Something like what you see in this video. The shortest distance between the antinodes is equal to the length of the sound wave. So, if you want to make such a device, you will need an Arduino board, for example, an Arduino Uno, you can use another Arduino platform. At least two ultrasonic emitters. They look like this. The driver of the DC motor. He's like this. The power supply is 12V, and the current is at least 2 A. In addition, you will need the program code that you see on my note. I like to take notes about it. I remind you that you need ultrasonic emitters, not receivers. Watch out and don't confuse the emitters with the receivers. So you can use a larger number of emitters, as in this project, but this will lead to an increase in current strength, and to heating of the driver. Experiment. I should note that the distance between the emitters should be a multiple of the wavelength, it will be easier this way, but it is possible in another way, especially if the distance between the emitters is not large. The connection diagram looks like this, you can vary the number of connected radiators at your discretion. I want to remind you that first you need to program the microcontroller separately from the circuit, after that you need to assemble the circuit as shown in the figure. That's all for now. I will send the photo to my Telegram channel. Yuri Kovalenok was with you