?Problems with DC12V adapter for Aircurve 10

palerider wrote: ↑

Thu Oct 01, 2020 1:14 pm

Sounds like you have another bad converter.

Palerider - you mean transformer on the adapter cord?
Converter is a component in the RV electrical system that translates 120v to 12v, it works fine.

khauser wrote: ↑

Thu Oct 01, 2020 2:37 pm

Norma, how big are the 6V batteries in Amp Hours?

One concern of connecting two 6V batteries in series is that they both have to be at about the same state of charge or one will limit the other.

The humidifier draws the lion's share of energy in any xPAP I've seen. So your observation is interesting. More tests will tell.

It's possible you got a second bad adapter, but that would require seriously bad luck.

But it behaves, as I've said, like power starvation.

210ah (at 20 hours), but as I said this happens with shorepower (which uses the converter and no battery).
Yes, batteries are the same state of charge, cells have equal specific gravity, and same manufacturing date.

Hmm, maybe I should turn off the converter for a few days to test that part. But as I said, it is only a couple years old and everything else runs fine and it is one of the better brands (as is the entire powercenter - holds breakers, fuses, and includes the converter/charger, ats, etc.).
Norma

I have zero experience with RV converters.

The Resmed cord is not typically referred to as a transformer ... there is no transformer inside it. It's a boost converter (https://en.wikipedia.org/wiki/Boost_con ... %20(load).).

Unlike the diagrams in the Wiki article, it is probably controlled by a dedicate boost controller IC. (By probably, I'm around 99% sure). That IC gets its power to run as part of the input. If the output draws enough to exceed what can be provided, the IC will stop, and that will stop the boost circuit, and the whole thing starts over. That's the reboot I refer to.

Since we believe the batteries are up to snuff (sounds like they are), the options are:
- a wiring problem along what I was saying earlier
- a bad adapter
- a bad bilevel that is drawing more power than can be delivered by the adapter

We talked about how you can rule out the first problem. If going direct to batteries works, the adapter is OK and there's an issue with wiring, else its either wiring or the machine.

The ResMed DC to DC converter supplies 90W, which matches the power brick for your unit.

Figuring out whether it's your Aircurve or your DC to DC converter that's the problem will be difficult, but I wouldn't think your Aircurve would work well if it drew too much power even when on the power brick.

palerider wrote: ↑

Thu Oct 01, 2020 1:11 pm

Norma45 wrote: ↑

Wed Sep 30, 2020 4:21 pm

I saw some posts (elsewhere I think) about making sure the wire was straighter and did that

Whoever said that doesn't know anything about electricity.

Actually wiggling a wire and it working (especially in some positions and not others) means there is a bad connection somewhere (wiring not connected well, touching something it shouldn't and creating a short, etc.) and if it happens regularly on new parts it would point to poor manufacturing (not making good connections).

Norma45 wrote: ↑

Thu Oct 01, 2020 2:42 pm

palerider wrote: ↑

Thu Oct 01, 2020 1:14 pm

Sounds like you have another bad converter.

Palerider - you mean transformer on the adapter cord?
Converter is a component in the RV electrical system that translates 120v to 12v, it works fine.

The thing from Resmed is a 12v to 24v DC-DC converter. It's not a 'transformer'.

I don't know what your RV stuff is called.

khauser wrote: ↑

Thu Oct 01, 2020 3:05 pm

I have zero experience with RV converters.

The Resmed cord is not typically referred to as a transformer ... there is no transformer inside it.

Actually, there ARE transformers in there, packed in with a whole lot of other circuitry.

Just to leave information for others who come across this problem.

Doing tests, I confirmed it was what I thought it was - when the aircurve10 demands more power it can exceed what the adapter can deliver.

For me, I sit between 10-14 pressure most of the time.
I use the humidifier but not the heated tube.
With the humidifier on level 4 or before, the dc adapter worked fine (one exception below).
Humidifier level 5 or above, I can have problems with the machine rebooting.
The exceptions - things that can pull even more power and cause a problem at settings that are normally ok....
On an exceptionally cold night (likely more power is needed to heat the water),
Or if the humidifier tank runs out of water (didn't have enough to get thru the night).

There might be more exceptions.

I have finished this discussion for me, so I won't be back to check any replies.