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A mini PPA v2,my first portable attempt. - Page 6

post #76 of 103

Have you tested charging the batteries with just that PCB alone?

 

Since it only seems to be a protection PCB not an actual battery management PCB

post #77 of 103
Thread Starter 
Have you tested charging the batteries with just that PCB alone?

Since it only seems to be a protection PCB not an actual battery management PCB


I'm not sure that is accurate, I am fairly certain that both battery PCB's that I am using regulate the charge as well as the discharge, however I don't think either of them regulate the charge current. I will need to look at the dada sheets of the controller ICs to be sure.
post #78 of 103
Thread Starter 
Have you tested charging the batteries with just that PCB alone?

Since it only seems to be a protection PCB not an actual battery management PCB


I'm not sure that is accurate, I am fairly certain that both battery PCB's that I am using regulate the charge as well as the discharge, however I don't think either of them regulate the charge current. I will need to look at the dada sheets of the controller ICs to be sure.
post #79 of 103

Two PCB's?

 

The wording for some of the protection PCB's for these batteries can be very misleading

 

example: http://www.ebay.co.uk/itm/PCB-Charger-for-3-Packs-3-7V-Li-ion-Li-Lithium-18650-Battery-Rechargeable-2-3A-/221118857088?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item337bb5ff80

 

"Charger PCB" - Although really this is only a protection PCB

 

Looking through ebay  and various other websites it's pretty much impossible for me to source a charging PCB for an 11.1v pack - only laptop style power bricks which are normally used for higher voltage RC car LIPO battery packs.

 

This is the type of IC which would be suitable for charging such battery packs which you want to use: http://docs-europe.electrocomponents.com/webdocs/10e2/0900766b810e269b.pdf

 

Evaluation kit version of that IC: http://www.maximintegrated.com/datasheet/index.mvp/id/3105

 

 

If for some reason I am completely wrong then please school me about my errors :(


Edited by miniq - 2/15/13 at 2:01pm
post #80 of 103

Nice stuff!!  This amp maybe a true worthy competitor to Justin's Pico Power.

post #81 of 103
Thread Starter 
Quote:
Two PCB's?

Yes and no. I am using one type of PCB in one amp, and another type in the other amp.

 

To clarify, Both battery management boards keep the cell pack from over discharging and over charging.

 

I am trying to test both to decide whitch one i prefer, but either one will work fine.

 

I have been away from this project for awhile, I will post an update soon.

post #82 of 103
Thread Starter 

Ok, I have been away for a few weeks, and have not been able to work on this much at all in that time.

frown.gif

 

My job sent me out of state and while i was away I simply did not have any  spare time to work on this.

 

However, I am back now, and shortly I will be caught up on things at the office that piled up while I was away.

 

An update is in order! I have the new PCB designs pretty much done, but I am working on a couple of upgrades to the amp that i want to include in the PCB order to keep costs down.

 

The first is a digital POT that will allow not only volume control, but also allow adjustment of the op-amp and buffer bias settings from a single encoder.

 

The second is a small DC/DC converter board that will allow this amp to be powered from a USB port, and then paired with a small DAC for a neat little desktop amp.

 

Both of these are still early in development, but hopefully they will work on the first try....tongue_smile.gif.

post #83 of 103
Any new updates to this awesome project?
I'm for sure interested in a PCB set or two, if there will be some kind of group deal later on smily_headphones1.gif
post #84 of 103

The PPAS was one of the best portable headphone amplifiers I ever owned, imo. Why hasn't this project taken off? A respectably built miniPPAv2 could be thrown together for ~$150 (no basis on that number whatsoever), I'd wager, and it'd slap any commercially produced portable amp that didn't have a price tag more than three times that amount, imo. What would it take to make this happen?


Edited by khbaur330162 - 1/13/14 at 6:02pm
post #85 of 103

This is such a funny coincidence - I found a PPAS near completion in my parts bin and just finished putting it in a case tonight with a simple 7809 regulator (OPA609 ground opamp, LM4562+LMH6321 right/left). A huge amp in a tiny package. :)


Edited by FallenAngel - 1/13/14 at 9:43pm
post #86 of 103

Don't tease me like this, Pavel.. Wait. Seriously? No. What are you saying right now?

post #87 of 103

Yep, awesome things in my huge container full of components. :p I found 2 PPAS amps, one with 2 9V batteries that I couldn't bring to life and destroyed in the process of trying to fix - salvaged chassis and batteries, that's about it. The other seemed to work, just needed some casework and is now a tiny desktop amp. :)

post #88 of 103

Want this one? It would take some serious tweaking to get a battery in there - LM317 set to ~ 11V output and another LM317 to trickle charge the 8.4V battery, all stuffed inside a Hammond 1455C802 case... It'll be challenge, but sounds fun. :)

post #89 of 103
Quote:
Originally Posted by FallenAngel View Post
 

Yep, awesome things in my huge container full of components. :p I found 2 PPAS amps, one with 2 9V batteries that I couldn't bring to life and destroyed in the process of trying to fix - salvaged chassis and batteries, that's about it. The other seemed to work, just needed some casework and is now a tiny desktop amp. :)

Oh, alright, so I still need to hand out the pitch forks and rally a mob of miniPPAv2 supporters, it would seem? *grumble grumble*

Quote:
Originally Posted by FallenAngel View Post
 

Want this one?

Maybe not. PM sent.

 

 

I'd make the miniPPAv2 if I could, but I have no clue about amplifying circuits, it'd be like a 3 year long process. But, even if I had a PPAS in my pocket a miniPPAv2 would still be ridiculously awesome. H22, where arrre you, dude?


Edited by khbaur330162 - 1/14/14 at 2:59pm
post #90 of 103
Quote:
Originally Posted by khbaur330162 View Post
 

I'd make the miniPPAv2 if I could, but I have no clue about amplifying circuits, it'd be like a 3 year long process.


I could design one, if there was enough interest.

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