palerider wrote:I believe you missed my point, which is that there is no DC motor in the Resmed S9/AC10 machines.

I did completely miss this, and I haven't a clue: If not a brushless DC motor, what generates the air pressure?

The Buck Converter Board "- Output" doesn't need a connector, it's common with the "- Input" connection. And actually, the 24V Converter "Ground Wires" are also common with each other. (I might have preferred a "floating Ground" output implementation, but that's not what they did). The 24V Converter...

and the DC motor (brutually reactive, asymmetrical square wave) Only, it's not, not even close... which does tend to call your other "SWAG"s into question. Yeah, I was waving my hands pretty wildly... and couldn't even spell 'brutally', I was getting so over-excited. In any case, I've now finished ...

Thank you both for correcting! I had assumed a "90W" CPAP, like a Resmed A10 (rather than a 10W XPAP)

FYI, for other crazy people wanting to experiment with DIY 12V to 24V adapter: $2.64 delivered, 150W boost converter: http://www.aliexpress.com/item/150W-DC-DC-Boost-Converter-10-32V-to-12-35V-6A-Step-Up-Voltage-Charger-Power/32650647286.html $3.99 delivered, 100W boost converter with LED voltage d...

How about NEMA ML1-P and ML1-S twist lock connectors? Alligator Clips can spring loose, the grip is really finicky. And "cigarette plug" adapters can't handle all the Watts which your connectors need to supply. A NEMA standard for mini-twist lock, 2-wire applications exists; the most compact is call...