[tomb]

  Any thoughts on the case to use? I'm particularly partial to the availability and ease of use of the 1455C series.

Agreed - 1455C801 would be nice - as long as you don't buy them raw.

 
 
As for the charger, some of you probably know that I'm partial to a complete package product.  Talented DIY-er's like FallenAngel are in the small numbers, unfortunately.  As for the rest of the unwashed masses, versatility = more highly-skilled work required and support issues that go with it.  My vote is for everything integrated, if possible.

 

[FallenAngel]

NiMH charging circuit with possible bypass for LiPo?

 

[Avro_Arrow]

  Any thoughts on the case to use? I'm particularly partial to the availability and ease of use of the 1455C series.

Thats what I was thinking too.

 

[Avro_Arrow]

  NiMH charging circuit with possible bypass for LiPo?

If I use a constant current / constant voltage charger, it can do both.
You just have to set the correct constant voltage.

 

[Avro_Arrow]

 
Talented DIY-er's like FallenAngel are in the small numbers, unfortunately.  As for the rest of the unwashed masses, versatility = more highly-skilled work required and support issues that go with it.  My vote is for everything integrated, if possible.

Yes, I'm listening to everyone...but thinking mostly about the less experienced to make it easier for them to build.
On the other hand, I want to leave some flexibility for the tinkerers.
 
So, CVCC  charger, I've posted the circuit before.
As many AAA cells or LiPo as you can cram in the case with some room left over for the board.
Dual color LED to indicate low battery voltage. Again, I posted this before.
Three channels with LME49990 and LME49600
TLE2426 for the rail splitter.
Hammond 1455C series case. Maybe Tom can grace use with his excellent case engineering skills...hint, hint.
 
I almost have something to design...

 

[vixr]

....

 

[dBel84]

great project guys. 
 
any thoughts on buck/boost power modules . Thinking of something lilke the TI module  http://www.ti.com/tool/lownoisesplitrailnoniso-boost-ref , this would allow a simple ( easily attainable li-ion battery ) in the 3.7V range to be used and generate decent rails for an amp, it is pretty small once implemented too  - this module gives 40mA which should be plenty for a portable. 

..dB

 

[Avro_Arrow]

  great project guys. 
 
any thoughts on buck/boost power modules . Thinking of something lilke the TI module  http://www.ti.com/tool/lownoisesplitrailnoniso-boost-ref , this would allow a simple ( easily attainable li-ion battery ) in the 3.7V range to be used and generate decent rails for an amp, it is pretty small once implemented too  - this module gives 40mA which should be plenty for a portable. 
 
..dB

Great suggestion.
I'm subscribing to KISS on this project though
 
Maybe we can do a more exotic "balls to the wall" project next

 

[wakibaki]

It's worth remembering seeedstudio.com and iteadstudio.com (slight differences in offerings and prices). You can get 10 off 5*5cm PCBs and 10*10cm PCBs for very reasonable prices. You can split (panelize) a 10*10 board to get 2 off 5*10 boards. Seedstudio in particular do a very good price, I try to buy 2 lots of 10*10 PCB and another small item (solar panel), this takes the price to just north of $50 (last time I ordered) which means postage is free. You have to split the boards yourself. I've bought many batches of boards there, I've never had any complaint and delivery is usually about 10 days to the UK. 
 
The service is so attractive, particularly the 5*5 and 10*10 sizes, it's started to influence the way I design.
 
w

 

[tomb]

 

 
Talented DIY-er's like FallenAngel are in the small numbers, unfortunately.  As for the rest of the unwashed masses, versatility = more highly-skilled work required and support issues that go with it.  My vote is for everything integrated, if possible.

Yes, I'm listening to everyone...but thinking mostly about the less experienced to make it easier for them to build.
On the other hand, I want to leave some flexibility for the tinkerers.
 
So, CVCC  charger, I've posted the circuit before.
As many AAA cells or LiPo as you can cram in the case with some room left over for the board.
Dual color LED to indicate low battery voltage. Again, I posted this before.
Three channels with LME49990 and LME49600
TLE2426 for the rail splitter.
Hammond 1455C series case. Maybe Tom can grace use with his excellent case engineering skills...hint, hint.
 
I almost have something to design...

Sorry - missed that before.  Thanks for the compliment.  I can hardly refuse after that.

 

[Avro_Arrow]

 
Here are some preliminary schematics:

 
Charger
 


Voltage Monitor
 

 
Rail Splitter
 

 
Signal Channels
 

 

[Avro_Arrow]

 
So, is there enough interest for me to start doing a layout?

 
Question, comments? 

 

[khbaur330162]

Still in.

 

[RagunaAsh]

I'm definitely interested! I know this is being made in the spirit of the PPA, but has there been any thought on exactly what kind of output power this would have? And (dare I ask) final cost?

 

[vixr]

I'm in