Apnea Board Forum - CPAP | Sleep Apnea
Will a 20 volt DC converter work with the S9? - Printable Version

+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: Will a 20 volt DC converter work with the S9? (/Thread-Will-a-20-volt-DC-converter-work-with-the-S9)

Pages: 1 2

Will a 20 volt DC converter work with the S9? - toller - 02-26-2016

I have a 90 watt 12vt DC to 20volt dc converter; stabilized and all that. Will the S9 operate on 20 volts rather than 24? Has anyone done so? I'm desperate to be able to go camping and my tether to 120 volts is raining on my parade, and the cost of a new dc converter is prohibitive for me.

RE: Will a 20 volt DC converter work with the S9? - pholynyk - 02-26-2016

Unfortunately, the S9 requires 24V supplied through an odd three conductor coaxial plug. It has a center pin, an inner sleeve, and an outer sleeve. Power is on the two sleeves, and I suspect the inner pin identifies the power rating of the power adapter. My old Lenovo T61 laptop has a similar plug. And an old Dell laptop I found, too.

RE: Will a 20 volt DC converter work with the S9? - toller - 02-26-2016

(02-26-2016, 10:27 PM)pholynyk Wrote: Unfortunately, the S9 requires 24V supplied through an odd three conductor coaxial plug. It has a center pin, an inner sleeve, and an outer sleeve. Power is on the two sleeves, and I suspect the inner pin identifies the power rating of the power adapter. My old Lenovo T61 laptop has a similar plug. And an old Dell laptop I found, too.

In fact the converter I have is a Lind de2045-1320 DC power adapter for Dell and Inspiron laptops.

Is the unfortunate part that it is 20v and not 24 or the odd plug? I thought perhaps some of you may have tried the 20v power adapter.

RE: Will a 20 volt DC converter work with the S9? - pholynyk - 02-26-2016

I guess the unfortunate part is that we don't know the exact function of the center pin, and we don't care to risk our nighttime companions.

RE: Will a 20 volt DC converter work with the S9? - toller - 02-26-2016

(02-26-2016, 11:17 PM)pholynyk Wrote: I guess the unfortunate part is that we don't know the exact function of the center pin, and we don't care to risk our nighttime companions.

I understand perfectly. I feel very much the same way.


RE: Will a 20 volt DC converter work with the S9? - justMongo - 02-26-2016

Actually, I do not think it's coaxial; but 3 pins and a shell.
The actual plug being a KPPX-3P
[Image: KPPX-3P.jpg]

RE: Will a 20 volt DC converter work with the S9? - pholynyk - 02-27-2016

Oops. Thanks for the correction, jM. I wonder why they changed to the coaxial plug for the A10.

Does anybody know the function of that third pin, the skinny one?

RE: Will a 20 volt DC converter work with the S9? - OMyMyOHellYes - 02-27-2016

(02-27-2016, 06:21 AM)pholynyk Wrote: Does anybody know the function of that third pin, the skinny one?

So ResMed can suck more money out of their customers.

They make it so you have to buy THEIR hundred dollar 24 v converter as opposed to just hooking up a perfectly good 24 v source which they may already have or which would be better suited to the pt's needs or task.

Yes, I have a great deal of contempt for ResMed over this issue. But no more than ResMed shows to their customers when they pull crap like this.

OMMOHY

RE: Will a 20 volt DC converter work with the S9? - eseedhouse - 02-27-2016

(02-27-2016, 07:20 AM)OMyMyOHellYes Wrote:
(02-27-2016, 06:21 AM)pholynyk Wrote: Does anybody know the function of that third pin, the skinny one?

So ResMed can suck more money out of their customers.

Well, this connector is a standard one and Resmed doesn't make it themselves, so it must have some other use. I'm not saying that they don't want to suck customers our of their money, just that it is not a bespoke one of a kind connector.

Usually in 3 pin connectors the third one is connected to ground. See yer standard 3 pin wall plug for instance.


RE: Will a 20 volt DC converter work with the S9? - justMongo - 02-27-2016

There is no "ground" per se. That is, there is no "Earth" like there is on a 3 prong AC line plug.
Plus, in house wiring, the ground conductor must be capable of carrying the same current as the hot.
i.e. -- in a house, 20 Ampere circuit, the hot ,neutral and ground are all 12 gauge wire.

I believe it works as 1 fat pin for power. One fat pin as the return.
The "skinny" pin is some sort of sense pin. Note it's limited current capacity.
The shell is connected to a braided shield for EMI suppression.
We have measured Voltages on these pins in old threads.

[Image: KPP.jpg]