Portable Bluetooth Boomcase

Hello,

The Boomcase is a vintage suitcase converted into a boomcase,
It has two woofers and two tweeters. The case is powered by one lead acid battery.
The boomcase can be charged via a 230V power supply. The amplifier delivers 15 watts of power per channel, and has a connector for an external sub-woofer (30W). You can easily take this case to the park or to the beach or just let it play at your home. This is my first instructable so I hope you like it.

Parts List:

- Suitcase: found in my garage.

- Speakers: found in a local second hand store.

- Buck convertor: http://www.aliexpress.com/snapshot/6451422603.htm...

- Switched mode power supply: http://www.conrad.be/ce/nl/product/511827/TDK-Lamb...

- Bluetooth module: http://www.benl.ebay.be/itm/Bluetooth-BLK-MD-SPK-B...

- Usual electronic components (resistors / capacitors / connectors / ...): found at a local electronics store.

- Lead acid battery: bought at local flea market.

- Lead acid batterycharger: found at a local electronics store.

- Heatsink: recovered from old Acoustimass speaker.

- PCB: http://www.elecrow.com/services-c-73.html

Tools used:

- Soldering iron

- Tweezers (for the SMD components)

- Wire Cutters/Strippers

- Dremel

- Drill

- Milling machine

First I designed the PCB,

I did this step first because I know I will have to wait for at least 3 weeks for the PCB's to arrive.

I started with a schematic that i found on the internet:

This scheme will never work on a 12V battery!
The voltage required on pin 7 (standby pin) of the TDA7377, is 5V in this configuration the voltage on the standby pin would be 1,9V and then the amplifier would never get out standby.
I replaced the resistor of 22K ohm with one of 10K ohm and the capacitor of 1µF with one of 10µF.

I altered it so I could make an extra sub-woofer channel:

I made it a mono speaker: joining the right and left channel together.

This joined signal I took as input for my sub-woofer pre-amp.

I designed the PCB with the Eagle cadsoft software but I lost the .BRD file so I can only upload the .SCH file. (truly sorry).

I have 2 other PCB's which I etched at my home one was for the bluetooth module and one was for the battery-level indication.

(The 2 Eagle files are attached.)

The PCB for the bluetooth module is just some kind of breakout board allowing you to chose yourself which control buttons you want on your boomcase (I chose only for the disconnect button but made the PCB for all the buttons).

The other PCB is for the battery control so you can see how much battery life you still have left.

This step is different for each case I chose for this layout because with this setup I cold fix the battery behind the tweeters and then the weight would be more evenly distributed. for the speakers I used 2 Marantz HD-180 speakers.

First I made all the drills for the exterior of the boomcase.

Because the suitcase was made from wood, I had to remove some of the wood with the Dremel if it was too thick.

You can see how everything is installed in the pictures above.

I had to ply brackets for the lead acid battery because there was no other way to fix them to the case.

I also have two diodes installed so the power supply cannot charge the battery because this would kill the battery.

You're done! Have fun! Make sure that the battery is charged before it reaches the red led otherwise the battery won't have a long life. I used a lead acid battery of 12V 13Ah and the boomcase plays +- 12h with it.