(06-06-2016, 02:32 PM)justMongo Wrote: You're pretty much stuck using the ResMed 12VDC to 24 VDC up-converter.
If I stick with the ResMed device when camping, the up-converter seems to be the way to go, for finesse.
Of course, putting two 12VDC 35Amp-Hour gel cells in series gives us 24VDC, so then all we need to handle is the 3.3VDC voltage regulator with 2.7KOhm sense resistor circuitry...
(06-06-2016, 02:32 PM)justMongo Wrote: So, the question should be, what current is drawn from the battery in that configuration.
It will draw about 1 Ampere. check this document: http://www.resmed.com/us/dam/documents/a...lo_eng.pdf
See page 20.
Thanks for locating that information that we can nominally assume about 1 amp for standard cpap settings. For an 8-hour night, that's 8amp hours, so, it seems like two nights would do with, at a minimum, a 16-amp-hour battery, so, the often stated 35 Amp Hour battery should be fine for a weekend, right?
(06-06-2016, 02:32 PM)justMongo Wrote: Seems you have access to a PR machine... Then you can use 12 VDC directly.
Yes. You are correct.
My good friend and I both abhor non-standard power supplies and cables (we met at an Apple conference, where we lamented their "walled garden" approach).
When I told him about the hugely non-standard ResMed AirSense 10 Audoset power supply requirements, he immediately gave me access to his standard-power-supply-fed Philips Respironics Bi-PAP Auto Bi-Flex 750P pictured below, so that I wouldn't have to deal with the purposefully-non-standard ResMed power supply issues.
He said I only need to give it back if his current machine breaks down.
This 12VDC device "says" it sinks 5 Amps maximum, but, just like with the ResMed, I suspect it's less than half that on average. Given 2.5 Amps, and 7 hours a night, a two-night campout should consume 2.5 amps over 14 hours, which would dictate a 35 Amp Hour battery.
(06-06-2016, 02:32 PM)justMongo Wrote: Someone like Sleeprider will be able to translate your setting from A10 to PR machine.
As you noted, Sleeprider is advising me for the task of matching the settings of the non-standard-power A10 to the standard-power 750P for camping purposes:
Given that the non-standard-power ResMed is set to automatic of 10 to 20 cm of water with a pressure relief of about 2 cm of water, so far I've set my friend's standard-power Respironics 750P to the following settings, which I am testing as we speak:
- Mode = Auto
- Max IPAP = 20.0
- Min EPAP = 7.0
- Max PS = 3.0
- Flex Type = None
- Rise Time = 0 <---------- this appeared when I set flex type to none!
- Bi-Flex = 3 <---------- this disappeared when I set flex type to none!
- SYSTEM = X2
- LOCK SYS = off
- Ramp Time = 0:10
- Ramp Start = 7.0 <---------- this dropped from 7.5 to 7.0 when I set flex type to none!
- Auto on = on
- Auto off = on
- Mask alert = on
- Humidifier = off
- Show AHI = on
- Split night = off
I think the 750P has a default minimum pressure support of 2cm of water, so, tonight I will probably change the Minimum EPAP to 8 (from the 7 that Sleepster recommended above) so as to better match the 10cm to 20cm APAP settings of the non-standard-power ResMed machine.
I'll test these settings again tonight, so that I have a ready-made 12 volt standard-power-supply cpap machine available to me, so that I don't have to deal with the issues that ResMed put on the table just to make the power supply non standard.