Philips Respironics power supply questions

Hi All,

I have a REMstar 560p CPAP machine that is 3+ years old and it's failing. I have 2 power supplies for that machine because I travel a lot and it's nice to leave one permanently beside my bed at home. I just got a new DreamStation dx500t11 as a replacement. It appears to use the EXACT same power supply. All of the specs listed on the stickers are identical to the specs on the new power supply. All three power supplies are genuine Philips Respironics parts. They're all 80 watts and the output numbers are the same. They look pretty much identical. I tested the polarity of each connector and it's the same for all three.

However, when I plug in one of the older power supplies, the new DreamStation powers up and then puts up a message saying [check power]. I cannot clear the message and the machine will not work with either of my previous power supplies even though it stays powered up. I don't get it.

I may have to break down and buy a FOURTH power supply to have as a traveling spare for this new machine. If you have any insight, I'd love to hear what you think.

Thanks!

SnootMask wrote:Hi All,

I have a REMstar 560p CPAP machine that is 3+ years old and it's failing.

how?

perhaps you can fix it, and use it for the travel machine.

Look at the output plug. Make sure they are the exact same diameter inside and out. Exact same length of plug. And look at the contact points inside and out. Make sure that the two power supply plugs are truly the same. There are ton of different sizes of these type plugs. Somethings not right here.

I have the Remstar S1Auto 560p. Uses the 80w power supply like you say. I looked up the Dreamstation and it appears to use the same power supply also. What you say does not make sense. If they have the same input/output specs, same polarity and same size plug they should be compatible. Maybe the new machine has a way of determining that it has an old power supply plugged in. I wouldn't put it past the manufacturer to make you buy a new power supply even though they have the same specs. Your probably going to have to contact the manufacturer to find out the answers you seek. Please let us know if you figure it out.

Wait a second. You said the old machine is bad. Maybe it's the old power supplies that are bad and not the machine. Would be weird that both old power supplies are bad though.

FYI, the output is 12 volts, 6.67 amps, and 80 watts. As long as the fitting is identical and the prior things match, you should be OK.

My son's pr system one used one size of adapter to go from machine to power supply, with his new dreamstation he was given a different connector. Its the same thing if you go from a pr system one to a pr 60 series, you need a different adapter... look it up at cpap.com. Trust me, I'm in the same boat, went from system one to 60 series and need to buy a different connecter.

The PR system one 550 used a 60 watt power supply with a smaller Diameter power connector.
The PR system one 560 came with a 60 watt power supply and then a 80 watt for use with the upgraded Heated Hose Humidifier.
all 560 use a Larger Diameter power connector.
The dreamstation 80 watt Power supply uses the same Diameter power connector as the 560 80 watt but something is different.
You can't use 560 power supply on a Dreamstation but you can use the 80 Watt Dreamstation power supply on the 560

https://www.cpap.com/productpage/pr-dre ... upply.html

Read this statement:

https://www.easybreathe.com/secure/file ... ctions.pdf

"While Respironics DreamStation Series devices operate from 12V direct
current, the DC port on these devices require a proprietary signal in order
to recognize a valid power source; therefore, the use of a 12V power
adapter is required in order for the CPAP Battery to power these devices."

dcheddar wrote:Read this statement:

https://www.easybreathe.com/secure/file ... ctions.pdf

"While Respironics DreamStation Series devices operate from 12V direct
current, the DC port on these devices require a proprietary signal in order
to recognize a valid power source; therefore, the use of a 12V power
adapter is required in order for the CPAP Battery to power these devices."

Wow, that is sneaky of them! I did get that message once with the correct power supply, but disconnecting and reconnecting fixed it!

Same specs , but the Dream Station needs to find the "Proprietary signal" from the power supply. So my hunch was right. Sorry to hear you have to buy another power supply.

Why do they do this? Just to force you to buy their product? Since all cords that are sold with the "UL" are understood to be safe by the insurance industry (when new), there would not appear to be any legitimate safety reason for doing this.

Note that the UL was set-up by the insurance industry in response to claims that were denied (or that the industry wanted to deny but couldn't) because consumers were using "unsafe" cords. The remedy was that the insurance industry would certify appliances as safe so they would not be hit with claims caused by unsafe appliances and avoid litigation. This was good for consumers, as they knew their appliances were safe and they know that if an accident occurred, their claim could not be denied for this reason. Electrical appliances are certified in other countries by the government or by similar industrial groups.

I assume it's so people don't mistakenly use the wrong power supply and damage the machine. Nice for the manufacturer also since they can sell more product.

Rob K wrote:I assume it's so people don't mistakenly use the wrong power supply and damage the machine.

that does make sense, since there are a lot of different things out there using a similar or identical plug.

Rob K wrote: Nice for the manufacturer also since they can sell more product.

how's that work, since you can't buy a machine without a power supply??

The machine is sold with the power supply, but if you need to replace it or want to keep a separate on in your carrying case (as the original poster does), you are forced to buy their product! Also, if you want to use a battery, you have to buy something they sell to generate the signal!

The original poster has to buy another power supply. The old ones are the same spec to work with the new machine, but they don't have the proprietary signal. The manufacturer will sell more product in this case. I don't imagine it happening too often though. I believe it's mostly to keep people from using the wrong power supply.

Rob K wrote:The original poster has to buy another power supply. The old ones are the same spec to work with the new machine, but they don't have the proprietary signal. The manufacturer will sell more product in this case. I don't imagine it happening too often though. I believe it's mostly to keep people from using the wrong power supply.

So this is interesting. I don't doubt that it's the case - this kind of thing is done in many other types of products as well. What causes me pause though is that the 12v adapter cord (for car/battery) for the Dreamstation (https://www.cpap.com/productpage/pr-dre ... -cord.html ) doesn't really look like it would be likely to have active circuitry in it that could generate such a signal. The two round things in the cable are very likely just noise reduction coils. I guess they could put the special circuitry in the cigarette lighter adapter plug..it just seems not terribly likely. Whatever the signal is, it has to be something that's not DC..and thus able to be filtered out for detection. When I get a chance I'll take my Dreamstation power supply and hook it up to my oscilloscope to see if I can tell what the special signal is (assuming it's not something that's transient). This is all sort of academic of course, but I am curious. That adapter cable is way expensive and that certainly makes it more likely to have some funky signal generator in it :/.