[miniq]

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

 

[H22]

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.

 

[H22]

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.

 

[miniq]

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

 

[purk]

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

 

[H22]

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.

 

[H22]

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

 
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....

.

 

[Heffa]

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

 

[khbaur330162]

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?

 

[FallenAngel]

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.

 

[khbaur330162]

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

 

[FallenAngel]

Yep, awesome things in my huge container full of components. 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.

 

[FallenAngel]

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.

 

[khbaur330162]

  Yep, awesome things in my huge container full of components. 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*

  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?

 

[Avro_Arrow]

  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.