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Work finished!

Adding two speaker is very easy and provide a all-in-one boombox without thinking to add external ones.

But, yes, if you want you can also add a big external acoustic box....

This entry was edited (3 months ago)

We need obviously two speaker, two plastic box and also a grid for protect speakers from accidental damage.

Do you remember this project? https://social.gl-como.it/display/3e3ce0df-1364-ba5d-e582-0a0037482860

Well, I'm thinking to Transform the old project into a modern multimedial boombox.ì by adding two lateral speaker.


Work finished! I'm really satisfied.

The test was successful as you can see and I adjusted the charging current to 2A like the original wall charger.

This is a DC power converter module. with high power (4 Amp) and stable output, it converts 10-32V DC input to 12-60V DC output continuously with a trimmer. The conversion efficiency is up to 95%. you can improve the heat dissipation when the current is more than 4A with a small fan.

There are "step-ups" on the market that could be used to solve my problem. At the input they accept variable voltages and at the output they maintain a constant voltage even with a fluctuating input voltage. The model I chose is this:

I'm thinking of making a battery charger for my e-bike that can use my car's battery. The end-charge voltage of the e-bike battery is 42v, so you need a step-up that brings the 12 volts of the car battery to 42v with a current of 2-3 like that of the battery charger of the original e-bike.

I often run out of battery midday and not having the ability to recharge the battery with a 220V outlet is frustrating.


The fatigue is also over... never again the old methods...😁

Et Voilà!!! Job is done!

This afternoon I went to the Brikolage Center to buy a plastic box to enclose the batteries with the charge controller and a connector for charging.

The work continues...yesss...we also need a switch for fire air-flow 😀

I got tired of using the blower or shaking cardboard when I make the barbeque to get the embers... I said to myself: are there more modern methods? Do I have everything I need? YESSS!!

FAN + Lipo Battery + Charge balacing board + wooden gun


Today we will see how to recycle the exshaust batteries of an old laptop together with a fan recovered from a CPU server.... But to do what?

HAHA...SUB at Work..!

But is SUB or a FOOTREST?
Maybe a STOOL or a futuristic CHAIR?

You decide.... for me it is a fine piece of furniture. 😉

https://social.gl-como.it/attach/10


Ok, we are finished! The sound is great and the low frequencies are well reproducted, especially the sub-sonic ones. I'm quite satisfied.

The best solution is Linear power supply made with a transformer 220v/24v followed to a bridge rectifier 5A and a 4700uF elecrolitic capacitor.

OK..... This solution is not reccommended.

The switching power supply is too near to Speaker magnet and produce a udible buzzing during listening. But also fixing far from magnet, produce udible noise...


We can opt a Switching one or a Linear one but a linear could be Big and heavy) .
Ideal are 32v/5a switching one or alternatively a transformer (sec 5 A min.) with a rectifier bridge and a high capacity electrolytic (4.700 uF)/50V) placed in parallel at the output . Better use a 0.1 uF in parallel with electrolitic one.

And now the electronics.... Class D amplifiers are very compact and have an excellent performance compared to those in class A / AB. The choice fell on this model that uses the STMicroelectronicsTDA7498 in class D available on EBAY for just over thirty euros. It is specifically designed to be coupled to a soobwoofer and can be powered up to 32V/6A.

The drilling table includes a 220V panel socket and two female RCA sockets (one per channel).
The BF signal will be brought internally to the input of class D amplifier.

And than buy a 37cmX37cmX1cm of wood slab where place the 30 cm /250W subwoofer speaker...

First of all I need to reinforce The internal structure...

IDEAAAA....YESSSS a powerful SUBWOOFER!

Yes, I have one item of IKEA Part number 301.093.10 .

Intersting shape! https://hu.ikea-club.org/item/30109310.html

Uhm...I'ts old, and I found it in garage. What I cando for recycle?


Magic swirl... 😜

And the software?
The choice is :

1) Raspberrypi OS
2) Libreelec
3) OSMC

Choose according to your intended use, all are valid!


And now....ASSEMBLING!

An official RPi power supply seems to be the key to getting high quality sound but we need a 12v 5A power subbly.. Beware of china models which are notoriously undersized power supplies which can introduce instabilities or explode in your face...

Step 4 was to find a 7” LCD on the market to correctly display the Raspberry output without bulky monitors ...
The choice fell on the original 7” touchscreen Raspberry model with 800x480 resolution, which costs around 70 euros.

The old pi2B version does not have wifi/bluetooth chipset but is required to go online. The alternative is buying a rpi3B but why?😉
My magical drawer is full of any king of dongle... which will allow me to play music from other devices such as tablets or smartphones or from remote location...

The third step was to purchase the DAC and class D power amplifier hat to place on top of the Raspberry PI2B . A good choice was X5000 board selling by Suptronics with integrated 192 kHz/24bit high-quality ESS DAC and the Texas Instruments ClassD amplifier (TPA3118) offer up to 2x35w of crystal clear amplification for best sound quality.
Referring to http://www.suptronics.com/miniPCkits/x500



It is the modification of an old project that you can see here https://www.gl-como.it/v2015/pi3-dac/
In particular, I removed the old DAC hat replacing it with a raspberrypi hat consisting of DAC and 35 + 35w power amplifier nor 5 amp switching power supply. Soon I will post Photo and links.... Stay tuned!



This voltmeter is suitable https://www.ebay.co.uk/itm/352627865033 . For the amperometer i will use an instrumets found in my drawer with a shunt resistance because 10A fullscale.

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