LiFePO4 battery psu for PUC2 Lite USB-AES converter

[Oceanw]

Hello for all!

Some backround first. My system: Laptop -> usb to PUC2 Lite USB-AES converter/reclocker -> Integrated Magic LX Powerbox amplifier (consist Hypex DLCP active xo & 4 x UCD180 amp modules -> Linkwitz LXMini speakers. My mains voltage for Powerbox amp is connected to large safe isolation transformer bought second hand.

Im quite impressed with sound quality thisfar, system is very enjoyable. However im not satisfied yet and need something to take interest in. This article about server/pc with LiFePO4 battery power got me interested:
"New" LiFePO4 Powered Server
Im tempted about it, but idea of also powering DLCP xo & preamp part of Powerbox could be done. BUT, being very novice with electronics I need easier tasks to start with.

PUC2 Lite can be first victim of this project. It needs 5V/250mV.
it takes its power from splitted dual usb cable which was delivered in original package. One usb to puc2 and two to pc. It has also input for external psu in frontplate (3,5mm socket).

Thisfar i have these in my shopping list:

*12V 36Wh LiFePO4 motorcycle battery from neighborhood shop.
*Sparkos Labs 5V discrete regulator
*Already have several Silmic & Os-con elcos 220uf, 330uf, 25V.
*3,5mm plug and wire.

I plan to use silmics or oscons before and after reg and thats it.
Is it just that easy to get very good battery psu for this digital device?

 

[GOR3]

LiFePO4 cells are about 3.3V each. Therefore use 2 cells (6.6V) and regulate that down to 5V. That way you're only burning up 1.6V, rather than 7V. (Also, I assume you mean 5V @ 250mA, not mV).
George

 

[Oceanw]

LiFePO4 cells are about 3.3V each. Therefore use 2 cells (6.6V) and regulate that down to 5V. That way you're only burning up 1.6V, rather than 7V. (Also, I assume you mean 5V @ 250mA, not mV).
George

Thanks for comment. Right, 250mA!
I checked 7805 datasheet and there were info that minimum input voltage is 7V thats why choosed 12V.

My oscons are 330uf. Any suggestions how many to use before reg and after? I also have Nihicon HW 2200uf 25V.

 

[GOR3]

I don't know the topology of the Sparkoslabs regulator and the product page to which you link doesn't say. If it's an LDO, the output capacitor forms an integral part of the feedback loop. The value of the output capacitor and its ESR can have a significant impact on stability. Take another look at the product page. It makes some specific recommendations of suitable output capacitors.
Regards,
George

 

[Oceanw]

I don't know the topology of the Sparkoslabs regulator and the product page to which you link doesn't say. If it's an LDO, the output capacitor forms an integral part of the feedback loop. The value of the output capacitor and its ESR can have a significant impact on stability. Take another look at the product page. It makes some specific recommendations of suitable output capacitors.
Regards,
George

Thanks again for your kind reply and apologies for delay.
I got advice from developer of these regs to use few hundred uf´s electrolytics before and after reg.

 

[Oceanw]

Something more.

I buy quite lot from Fiverr for my work related things. I was interested what they can offer related to electronics.

My criteria for Fiverr suppliers were:

*I use 12V LiFePO4
*Device needs 5V / 250mA.
*Very low noise.

Heres what i got from electronic engineer with 5 stars history.
What do you think?

An externally hosted image should be here but it was not working when we last tested it.

 

[Oceanw]

Something more.

I buy quite lot from Fiverr for my work related things. I was interested what they can offer related to electronics.

My criteria for Fiverr suppliers were:

*I use 12V LiFePO4
*Device needs 5V / 250mA.
*Very low noise.

Heres what i got from electronic engineer with 5 stars history.
What do you think?

An externally hosted image should be here but it was not working when we last tested it.

Hi,

This cost me few bucks and i share it with you free, some comments please
What do you think about design?

 

[Oceanw]

Hi,

This cost me few bucks and i share it with you free, some comments please
What do you think about design?

FYI, its not final but for review to lead way to final design.
Would there be better more suitabel dc stepdown converters for this purpose?

 

[randytsuch]

FYI, its not final but for review to lead way to final design.
Would there be better more suitabel dc stepdown converters for this purpose?

Might just be me, but I don't see anything to review or comment on?

EDIT: Nevermind, for some reason I see it now

 

[Oceanw]

Might just be me, but I don't see anything to review or comment on?

EDIT: Nevermind, for some reason I see it now

Hi Randy,

Ill post final schematic as its ready.