This is sort of a follow-up video to the one I posted a few weeks ago about the Pixl 6000. That video ended up being one of the most viewed videos I have ever published, so obviously when I saw this lying on the path, I took it as a sign to make a part 2! I was very critical of the 6000 because of how ridiculous the waste of materials was, and in that video I asked why, given it was already based on cartridges, they did not make it reusable, and this device is exactly that, a rechargeable base unit with a replaceable cartridge containing the coil and liquid.
The device itself was very well made and well designed, I would go as far as to say it was overengineered! The whole board was coated in some sort of conformal coat, however, it was much harder and thicker than usual, almost as if they used potting resin for the coat. It is completely unnecessary in this application and also significantly impeded my ability to reverse engineer it. However, despite that, I was able to discover some extremely cool pressure switches. As the name "duo" implies, the device has 2 cartridges with 2 flavours of liquid in them, and on the PCB there were 2 pressure switches. I was expecting to see the "microphone style" capsules; however, they used a form factor I had never seen before. At first I assumed they were crystal oscillators for the microcontroller, however, I soon worked out they were pressure switches! They had a small via under them to allow the pressure onto the can, and I assume inside is a silicon wafer with a microstructure on it similar to the microphones used in earbuds. The coils were then switched through 2 discrete transistors (I'd assume they were N-channel MOSFETs, but I didn't check).
There is only one question remaining: "Why was it dumped on the ground?" That's something I do not know... I suspect either people do not know or could not find replacement cartridges. I am not sure if they are available directly from the manufacturer or whether they are made by 3rd party companies, but I did find some companies that claimed to sell them from a quick Google search.
Hopefully you enjoyed the video, as always, leave any questions in the comments, and I will do my best to answer them!
#electronic #electronics #electricity101 #lithiumbattery #lithium #usb #batteryequipment #improved #teardown