In one of my articles(https://electronics83.com/index.php/how-to-make-a-magnetostrictive-emitter-and-conduct-experiments-with-ultrasound/) , I told you how to make an ultrasonic magnetostrictive emitter myself and conducted several experiments with it. Based on this emitter, you can assemble a mini ultrasonic engraver with which you can make inscriptions on metal and glass. The metal should be small and soft aluminum will do.
In short, the engraver consists of a round magnet from the speaker, a coil and a ferrite rod, which oscillates at a high frequency under the influence of an electromagnetic field. points, in my case, for the experiment, I installed a sharp screw, since it could easily be glued to the end of the ferrite rod.
The IRL3103 field-effect transistor is installed on a small radiator to remove heat. On the generator, I set the frequency to about 32.2 kHz and the signal amplitude at the generator output is 10.5V. when the supply voltage on the key is 16V.
With the correct setting, a squeak will be heard from the magnetostrictive emitter. Now we touch the metal with the tip of the screw and try to write something on the metal. If the lines are weak, then change the generator frequency until the engraving depth is acceptable.
This is about the depth of the lines on the metal. When engraving, small shavings of metal should leave the metal.
You can watch a visual video of how this ultrasonic engraver works.
