So i'm trying to build an ultrasonic levitator by following the build on mike's electric stuff's channel h ttps://youtu.be/qy1w6rTpC2g . I've set everything up same as he did, following the schematic. 
I'm using a standard power supply rated 12V 0-6A. When I power it up and have my oscilliscope attatched to the output of the FET I get a square wave that looks like this. 
It seems to look ok to me. I've gone through a load of old ATX power supplies to find transformers but no matter how I connct them to my driver circuit it has no affect on the transducer and I've tried absolutely every combination of pins and windings possible many times. Sometimes I get the same voltage at Vin and Vout, sometimes Vout is arround 40v but I've never been able to get it high enough to drive the transducer correctly. Is there any where I can buy a transformer that will suit this purpose as an individual component or what other appliances could I potentially scavenge one from ? or have I done something completely wrong? I am quite new to electronics.
Thank You in advance
Best Answer
Your driving frequency(from the oscilloscope plot) seems to be too low for ultrasound. The ATX PSU transformer is designed to work at more than 25khz and will have a low impedance at your frequency causing it to overload the power supply. This might explain the low Vp-p of the output waveform.
Since you are new to electronics, I wouldn't recommend building this circuit due to the risk of high voltage and damage from ultrasound.