DIY magnetic fluid speaker

[Thank you/doge]
[Video has been uploaded to Station B] https://www.bilibili.com/video/BV12V4y1x7R5?vd_source=182c12d6e4a19ba505f0a20adb31dedc#reply124791415728
I started to see the DIY works of the YouTube boss last year, but it is a pity that it has been delayed. Mass production (it seems to be mass production recently, interested students can pay attention). [Youtube homepage https://www.youtube.com/c/DAKDJung_burnslap]
I tried to use Arduino to analyze music to control magnetic fluid, but I gave up because I had no coding foundation. It wasn’t until a few months ago that the YouTube master’s work was uploaded to Douyin, and after reading the works of other authors, I learned that electromagnets can be controlled with mos tubes. Then I made this DIY work.
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[Circuit component purchase]
First, I purchased a 2.1 Bluetooth amplifier board. Because I want the magnetic fluid to beat with the bass, 2.1 is a must. (Because the module has been sealed in the box by me, I replaced it with a buyer’s show and then bought the corresponding mos tube (very cheap, two yuan), boat-shaped switch, and electromagnet (the model I used is p45/30 , diameter 45mm, thickness 30mm, suction power 40kg), speakers (I use box-type speakers to avoid poor sound effects from wooden boxes, it is best to match the impedance and power requirements of your Bluetooth power amplifier module), etc., I will not go into details one by one.
ps: The Bluetooth amplifier I bought supports AUX input, but I don’t think it is commonly used, so there is no wire hole on the casing. If you need it, you can just modify the drawings yourself.
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[Magnetic Fluid Preparation]
Purchase online . The magnetic fluids are all high-density water-based, which will sink to the bottom in the water, making it difficult for the electromagnet to pull up. Even if it is attracted, it will always have a tendency to fall, which is not beautiful enough. I bought a formula from Xianyu to improve it. Here is the announcement for everyone:
1. Use pure water to prepare saturated saline, pump out the water in the bottle, and gradually replace it with high-concentration saline.
2. Attract the magnetic fluid to the mouth of the bottle, and inject lighter kerosene into it with a needle. Generally, a few tenths of a milliliter at a time is sufficient, and then shake well.
3. Observe the state until it becomes a complete spherical shape and has a tendency to float (if too much is injected, the effect will be poor)
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[Shell Production]
Online tutorials are all based on 3D printing, which is expensive and requires secondary processing for rough printing. Here is a website with drawings for laser cutting wood boards. You can adjust the size to generate drawings as needed.
https://www.festi.info/ boxes.py/I
 
used sketchup modeling to calculate the spatial collision, which is basically the most suitable size ratio for this bottle.
PS: There are no screw holes in the bottom plate of the drawing. I used an electric drill to drill holes and screw the Bluetooth module on the bottom plate.
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next step is the assembly process. . —————— [I forgot to put the wiring diagram, please make it up] Students with high requirements can also purchase a self-locking switch with an aperture and install it on the front as decoration —————————— [Finally, let’s talk about the cost] Shell Laser cutting 30 acrylic translucent plate 15 speaker pair 16 Bluetooth power amplifier module 45 led light bar 1 meter 11 boat-shaped switch 1 power socket 5 24v power supply 25 lighter kerosene 6 mos tube 2 magnetic fluid about 30 I can’t remember the electromagnet 35 The total is about 220 yuan, and there are also some syringes and other consumables. ——————Please leave a message to me if you have any questions. If there are many people, I may join a group!