Just a bunch of pics


One more information about the whining noise the Pyra does (I've already posted about this in the other thread, so most of you will already know):

As it looks like, we don't need to use Tantalum capacitors.
Nikolaus found a different solution by replacing somr parts.
Here is his detailed explanation (from the other track):



So basically, the tps2505 (the "wonky chip") drives the capacitors with an audible frequency - which is causing the noise. By replacing it with different ones, we can change the frequency into a non-audible one.
From the datasheet it sounds like the new chip uses PFM to maintain light-load efficiency, so isn't there a concern that we'll get sub-harmonics that will still cause audible noise? From the datasheet:
During Power Save Mode, the part operates with a reduced switching frequency and lowest supply current to maintain high efficiency.
 
I'm sure you've checked all the usual sources for conflict-free, but the Tantalum caps in some specs are not too much more expensive; tantalum in general is pricier than you like but the conflict free.. 10x the price is okay in small quantity? I've never looked too hard, but we have Kemet supplying them all over .. I think even digikey has them. Theres a local Kemet supplier 10 minutes from my house, but I think he only carryes the .1uF through-hole units, not the 0305 or smaller SMT units. Bloody pricey .. strip of 100 of them was like $60 or something, but conflict free (or a scam, one or the other...)

random link:
https://www.digikey.ca/product-detail/en/kemet/T491A105K016AT/399-3678-2-ND/818539
10c ea at digikey for these 1uF ones,at quantity of 2000.

jeff
 
I think tantalum caps are plan z or something by now. They've got a plan A and they're very keen on it (using two chip instead of the one wonky chip and upping the charge frequency to something above 1MHz.

Regarding the analogue vs digital debate, the last two hurdles encountered (the sirring noise and the RAM voltage drop) were very analogue in nature; a bump charging circuit is an analogue device, and voltage drops are analogue.
 
@EvilDragon What is the status of the plastic insert that goes in the lid with the metal surround? And the metal surround? Would those be the last non-electronics pieces still missing?
 
I actually typed that I thought they would be anodized and never submitted the post.

Still, it would be great to have some silver colored ones. I do have sandpaper, though.
 
@rygD As I understand it, anodizing produces an oxide layer, which then is a very good substrate for dye but also means physical protection. Wouldn't hen sanding the coloured part off mean getting rid of that protective layer and reducing the overall material.

Nevermind, it just occured to me, that we are talking about the logo plate. For some reason I had casing in mind.
 
Is this Metal Frame around the Logo Stainless??
The Pyra should be quite long living, you can change the CPU Board and the Battery, whitout the need of a new device
But I don’t want a rusty Pyra in 20 Years..
 
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