Finally! Somebody is posting a battery/DC power thread to ApneaBoard!

[OMyMyOHellYes]

OK -

I see where PR has out a DC cord that hooks up to the Dreamstation units and an automotive cigar lighter plug.

There has been talk/speculation as to the requirement for a mystery signal along a third wire as a requirement to make a Dreamstation run.

Anybody have experience with this? I ask because the PR system doesn't make you go through a brick - it is a simple two wire cord assembly. Or looks like it. Has anyone gotten the cord or taken it apart to see what makes it tick? It seems if it is really just a two wire cord (with two inexplicably ginormous RF chokes), then what/where is the mystery third conductor signal coming from? And if it is maybe a resistor molded in the plug end, shouldn't I just be able to run off a battery/DC source if I cut off the cigar plug and the RF choke on that end and replace with a PowerPole connector to hook up to my battery backup???

OMMOHY

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[sdb7802]

I bought the DreamStation dc cable and it's got a 20K ohm resistor molded in the plug. The resistor is connected between the center pin and the inner barrel (+12V). Outer barrel is ground.

Some testing with a power supply and a decade box shows the DS needs to see between 18.9K to 26.2K to power up and run without an error screen. The blower will not start with the wrong resistance.

You're right that the cable is just two-wire zipcord with humongous beads and you should be able to chop off the cigar plug and attach the powerpole connector. The cigar plug has a fuse, led, and resistor.

[OMyMyOHellYes]

Well, not the greatest thing (and actually, I can't see that it serves much, if any, purpose, except to force folks to buy that particular cord), but it beats having to buy a $100 brick. I wonder what would happen if I just started cutting off plasti from around the ferrite. Two half cores with plastic molded around them around the wire? Or, just cut off the plug end at the ferrite and add a PowerPole at that point!

OMMOHY

[OMyMyOHellYes]

Well after some ruminating and reviewing the earler thread http://www.apneaboard.com/forums/Thread-...ery-Cables I was wondering what the impact would be of running a PRS1 with the cable for the Dreamstation. Yes I know that PR warns the cables are not compatible, but it seems 12 V outer gnd, inner barrel pos, same same as the PRS1, with the center pin unaccounted for.

I wonder what it would think about the center pin? NOT that I NEED it, I hope to be GTG for the next several years with what I got now, but if I was a forward thinker, that could make things simpler to just cut the plug off of the Dreamstation DC cord and terminate it with PowerPoles, as if I had a Dreamstation, so that when I may get one .......

Has anyone disassembled a PRS1 and seen if that center pin goes anywhere or is just vestigial on that machine? It's a shame we can't get out hands on wiring diagrams for these machines. Or more a shame that the manufacturers make changes like this just to mess with everybody. I wonder if we might find a PRS1 DOA to do an autopsy on ....

OMMOHY