Big Clive does great teardown videos, and I especially appreciate his patient and thorough reverse engineering circuit walkthroughs – and this one is one of the best I’ve seen so far:
I bought this from Banggood, but it’s quite a common device on eBay if you search for USB plasma ball. Once you see that it radiates a very high voltage gradient at high frequency you may choose not to plug it into, or place it near anything expensive….
It’s really nice to see that the circuitry inside has not changed from the original units from many decades ago. If anything the components have improved, making the unit more efficient.
If you like high voltage electronics and plasma then this thing is worth buying just for the PCB inside. It’s very hard to wind reliable high voltage, high frequency transformers like the one used here, so it’s worth every penny just for that little flyback transformer.
Note that it’s best not to use the circuit without a load on the transformer to protect it against excessive open circuit voltage.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.