3r3143.  3r3151. However, I just repeated the finished device described by in this article 3r3r79. . 3r3143.  3r3151. Brief information on the device and experiments with levitation are shown
in my video r3r379. (experiments 3r3321. begin at 2:0? ). 3r3143.  3r3151. 3r3143.  3r3151. The most important element of this device are ultrasonic piezo-emitters, which can be taken from a sufficiently popular ultrasonic distance sensor (on the aliexpress, search for “ultrasonic distance HC-SR04” at a price of 70 rubles). 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. On the surface of the piezo emitter, which was the receiver, there is a drop of gelatinous glue. Presumably, this is done to better absorb the ultrasonic wave. It is desirable to remove this drop with a small screwdriver. 3r3143.  3r3151. 3r3143.  3r3151. in the original article 3r379. . As a result, the circuit should produce voltage pulses of ± 12 V with a frequency of 40 kHz. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. After assembling the circuit, it is necessary to install piezo emitters opposite each other, leaving the possibility to change the distance between them. I used a metal constructor, in which an interesting detail was found with longitudinal cutouts for screws. I don’t remember from which set this part, since I had long been buying sets of domestic and foreign manufacturers (M4 screws, pitch 10 mm) and put them all in one pile. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. I selected the distance from 25 mm. Gradually reduced it by half a millimeter and checked how the particles of foam are hanging. Stopped at 22 mm, while the particles hung best. In the original article there is a way to find the optimal distance using an oscilloscope. If one piezo emitter is temporarily disconnected from the generator, then it becomes a receiver and gives a sine. It is necessary to combine it in phase with a rectangular signal generator. 3r3143.  3r3151. 3r3143.  3r3151. 3r33112. 3r3143.  3r3151. 3r3143.  3r3151. When the optimal distance is found, you can begin the experiment. To do this, you need to prepare small light particles: balls of foam (also artificial foam snow), pieces of napkin, paper and thin foil (potal), Christmas decorations such as “rain”, large sequins. With the help of a grid paddle, you need to bring them into the area between the piezo emitters and lower the paddle. The particle will be captured in one of the nodes of the standing wave. These nodes are about 4 mm apart. You can bring several particles at once. Depending on the size and shape, particles can hang still, oscillate or spin. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. 3r3143.  3r3151. Oddly enough, for the time being on aliexpress there is no this device in the finished assembled form in a beautiful case. But there is a set for self-assembly of a more powerful levitator of 75 piezo emitters (search on request "Acoustic Levitator", price about ?000 rubles for an unassembled version). 3r3143.  3r3151. 3r3143.  3r3151. 3r33140. 3r3143.  3r3151. 3r3143.  3r3151. Thank you all for your attention, I hope the article will be useful. Happy levitation! 3r3152. 3r3151. 3r3151. 3r3151. 3r3149. ! function (e) {function t (t, n) {if (! (n in e)) {for (var r, a = e.document, i = a.scripts, o = i.length; o-- ;) if (-1! == i[o].src.indexOf (t)) {r = i[o]; break} if (! r) {r = a.createElement ("script"), r.type = "text /jаvascript", r.async =! ? r.defer =! ? r.src = t, r.charset = "UTF-8"; var d = function () {var e = a.getElementsByTagName ("script")[0]; e.parentNode.insertBefore (r, e)}; "[object Opera]" == e.opera? a.addEventListener? a.addEventListener ("DOMContentLoaded", d,! 1): e.attachEvent ("onload", d ): d ()}}} t ("//mediator.mail.ru/script/2820404/"""_mediator") () (); 3r33150. 3r3151. 3r3152.