Here is new old Music box with few modifications and changes. First of all I removed old Amplifier unit which was ridiculously inefficient and at the same time with very bad characteristic. After searching for new Amplifier circuit I decided to make 10W Amplifier with TDA2003. All i can tell is that was very good decision. It allows low power devices as MP3 ( mV) to reproduce great sound with 6-12V Power supply. With Solar Panels attached on the top of the box I would say it become GREEN BOX. I don't have to charge batteries anymore, it charge itself on the sun.
**Upgrades**
- New Amplifier
- New batteries
- added connector for charging
- added USB 5V charging connector/step down converter
- added Power On LED (Green)
- added New Speakers inside box
- speaker switch IN/OUT
- 2 Solar Panels ==12V
*New batteries
From some laptop. They are not normal 18650 batteries but slightly longer, they fits in 18650 charger. As for voltage they are fully charged on 4-4.05V. I'm using 3 battery connected in series. So it gives me around 12V
*Connector for charging
Normal connector from laptop adapter.
*USB 5V
I'm using internal battery for charging Smartphone/Mp3. With mini step down converter, Voltage is set to 5V even if battery voltage drops down to 7V.
*New Speakers
New speakers come from monitor. They are 8 Ohm each so in parallel 4 Ohm which is great for Amplifier.
*Speaker Switch IN/OUT
The middle unused switch is used as it was planned to switch between 2 Speakers inside box when I don't have any external Speakers or outside Speakers so you can close the box and carry it around
*Solar Panels
I bought 2 solar panels from ebay for 4$. One solar panel has 6V/160mA so with 2 panels in series I get 12V/160mA.
**AMPLFIER SPECS**
TDA2003 "10W" sinks around 80-120mA at 12V depends on which speakers are used IN/OUT. Power supply voltage can go up to 18V with bigger Voltage you get bigger Amplitude which led to better sound.
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| Inside box |
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| New Speakers |
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| From left to right -->3.5mm input jack-->USB OUT/for charging-->5.5mm Input charging jack |
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| 2x 6V/160mA Solar Panels connected in series |
That's all for now. Next thing I'm working on is new VU-Meter which will show Low Frequency (bass) on the 2 rows of LEDs
I hope you like it! Fell free to ask whatever you want.
