3+3watt Speaker set DYI need advice!

[Christonio]

Hello guys, I'm new to this forum and I would like to get a simple answer- will this work or not, maybe some advice.
So I'm planning to build a 3+3W stereo speaker box, I'm planning to make it portable too. I will probably use plywood for the body, but I came here not for that.
Parts:
1. 2x 3w 4ohm Speakers- http://www.ebay.com/itm/331269348255?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
2. 5v mini amp for 3+3w- http://www.ebay.com/itm/271646993437?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
3. Female 3.5mm jack so I can have the cable seperatly (I will cut off the useless male jack off)- http://www.ebay.com/itm/291203151289?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
4. 5v step up module-http://www.ebay.com/itm/DC-DC-Boost...799?pt=LH_DefaultDomain_0&hash=item1c34acdeff
5. Female USB A port, this thing im going to buy in my local electronic store. I will use this to get some juice for the speakers off my PC's usb port.
6. 2x Lever switch I will buy these at a local store too, these should cut off the battery off the whole circuit, so it can charge.
7. 3.7v 2800mAh tablet battery for "portability"- http://www.ebay.com/itm/141012790475?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT
8. Micro usb charger module I think this thing should charge the battery when its dead, firstly cutting the circuit off with the switches. -http://www.ebay.com/itm/5V-1A-Micro...858?pt=LH_DefaultDomain_0&hash=item33917817ea

Something I spent 30minutes using paint =b Sorry for not being able to make it in electrical circuit diagram, I'm not familiar with it enough yet.

Thanks in advance guys, I probably made it too complex than it actually is, but oh well...

 

[Arouse1973]

Seems reasonable. The only issue I can see is I don't think the step up converter can supply enough current to drive the amplifier when turned up-to max it's only rated at 0.5 A. Also I don't know if that little boost converters supply lines will be clean enough so as not to interfere with the quality of the audio. If this is an issue a small inductor and capacitor can be fitted in the power line to prevent this.
Adam

 

[BobK]

Unless you can speak USB and negotiate for more, a USB port on the computer is only required to supply 100mA, which, when multiplied by 5V is only 0.5W. You need 6W. So no, it will not, in general, work.

More explanation: To get even 500mA out of your USB port on a computer, you need a microcontroller that will negotiate for the higher current, and even then, you only have 2.5W, not 6.

Equivocation: Many USB ports will provide more current without the negotiation, so, depending on where you plug it in, it might work. But no guarantees, bit it might drop out if you use another USB device on the same computer.

Solution: Get a 2A USB charger, it will be able to supply 10W continuously.


Bob

 

[davenn]

you are showing the power connections from the amplifier board going to the incorrect places on the USB board

you have them going to data + and data - instead of GND and 5V


Ohh and further to the comments by the other 2 on your voltage/current requirements

You show a 3.7V battery for an amplifier that requires 5V to work properly .... see a problem there ?


Dave

 

[Christonio]

Thanks everybody for your answers, I'll try to get some adjustments.
Dave- ye thanks, lol, my bad. And there is a 5v step up converter so the amp gets 5v instead of 3.7v, so theoreticaly it should work.. =/
Bobk- What if I use USB 3.0 for this? I should get a new female port then, shouldn't I?
Arouse- not sure if chinese bullshit, but thats what they say: Features:
Can use the computer USB port 5V power supply
or using a mobile phone charger USB port 5V power supply
battery power can also be used

AND:
Specifications:
Operating voltage: 2.5V-5.5V

Waiting for your answers =b

UPDATE: thats the video I found this amp on, doesn't seem like crap fake video as he has many other tutorial/electronics videos. And he runs the amp off a usb port, not sure what magic is that but I like it.

 

[Christonio]

Damn it! I didn't post the link to the video, here it is:

 

[Arouse1973]

Unless you can speak USB and negotiate for more, a USB port on the computer is only required to supply 100mA, which, when multiplied by 5V is only 0.5W. You need 6W. So no, it will not, in general, work.

More explanation: To get even 500mA out of your USB port on a computer, you need a microcontroller that will negotiate for the higher current, and even then, you only have 2.5W, not 6.

Equivocation: Many USB ports will provide more current without the negotiation, so, depending on where you plug it in, it might work. But no guarantees, bit it might drop out if you use another USB device on the same computer.

Solution: Get a 2A USB charger, it will be able to supply 10W continuously.


Bob

I thought the USB was just for charging the battery, didn't notice the other USB
Cheers
Adam

 

[Christonio]

I thought the USB was just for charging the battery, didn't notice the other USB
Cheers
Adam

Thanks and no probs. So it should work, ye? Well going to order my parts and build it. I will let ye know how it goes and I'll probably make a build log so others can makr this too if its good.
It should be done in a month or so because of the shipping.

 

[Arouse1973]

Good Luck.

 

[Christonio]

Good Luck.

Thanks!
Edit: I'll keep this open if some people want to point something out or maybe get an update on the progress