Portable Speaker With Bluetooth
by Kulqie in Circuits > Speakers
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Portable Speaker With Bluetooth
Pretty simple speaker, very good battery life, build in bluetooth.
It's assembled with
- laser cut 4mm plywood (31cm x 8cm x 8cm)
- 4x 2" drivers from small notebook speakers (EARISE AL-101, they are surprisingly good)
- 2x 18650 3000mah
- TP4056 charger with cell protection
- bluetooth module
- 3.5mm female jack
- basic on/off switch
- 2x 3W*2 class D amplifier (pam8403)
- optional: 2x step-up(boost) voltage converter
Box
The plywood was cut with "tooth" shapes so it's easier to glue. Heat from the laser bend it a litte.
Apply glue to every panel except top or back and put it together
Back Panel..
I forgot about holes on back panel and had to improvise a little. Drill and wood file ftw.
Back Panel
Hot glued switch, jack, TP4056 charger (I added a heatsink), pay attention to that little hole next to it and hot glue on charger LEDs, it will lead light to this hole and indicate if battery is charged or not :).
Hole one the left is on/off switch of BT module covered with wood.
Wiring
I used a cheap bluetooth module with on/off button and jack output, so you can use it as bluetooth speaker or just as aux speaker when BT is off.
If you want a better module i recommend CSR6035/CSR6045 module (~7$ on aliexpress) but you have to figure the wiring on your own ;). http://www.aliexpress.com/item/Bluetooth-4-0-Stere...
The PAM8403 amplifier is small, powerful,power efficent... and costs nothing
http://www.aliexpress.com/item/10PCS-PAM8403-Super...
Charger - it's important to use TP4056 WITH cell protection, so they are safe from over discharge
http://www.aliexpress.com/item/2pcs-Lithium-Batter...
Capacitors that I used may be too big/useless but it's good to have one than not having it at all :D.
optional: to achieve better sound quality on higher volumes put an voltage converter (from 3.0-4.2 to. 5.0v-5.5v) before amplifier (one converter for one amp), most of the bluetooth modules uses 3-4.2v so leave it straight to battery. And you should use batteries with bigger capacity/more of batteries connected in-parallel.
(this one is nice, with 2A current) http://www.aliexpress.com/item/2pc-DC-Boost-conver...
Soundproof the Box
Last thing, fill box with wadding or something similar. In my case it's organic cotton (don't use viscose).
Batterylife
Cells are from disassembled 6000mah powerbank (kinda doubt they're 3000mah each).
On max volume with aux (BT off) it was playing music for over 8 hours and probably could make another 5 hours if not more.
You can finish the look with lacquer, veneer or leave as it is, looks quite nice ;).
CAD Project
Here's my CAD project for 4mm plywood