USB-C PD to power Dreamstation Bipap?

[spease]

Has anybody tried powering a Dreamstation Bipap via USB-C PD at 12v?

I’ve been looking for a solution for this, but the closest thing I’ve found are bare circuit boards or possibly using a Li-Ion laptop battery pack to implicitly convert USB-C input to a 12v barrel plug.

Is there anything special about the retail power supply compared to a typical 12V DC power supply?

Thanks.

[Goofproof]

Sounds like you want to reinvent a wheel, I'd start with drawing a circle. Jim

[spease]

There doesn’t appear to be any product that does what I want, which is namely to use a powerful enough USB-PD charger or battery output with the machine. This opens up a whole ecosystem of commodity products rather than an extremely limited set of “choices” and having to lug around battery/adapters specifically for the bipap (in addition to things for phone/laptop). The 80-some watt adapter for the machine is also much bulkier than a 100w USB-C charger.

This ecosystem is also likely to continue to grow with time due to the larger market for laptop accessories, so it’d be a good investment for the future - it opens up a lot of choices. If it’s technically viable.

[HiGreg]

One issue with providing Power through USB-C PD is that it can supply limited power/current at 12V. To meet the specifications of the Dreamstation, a power supply needs to supply 12V at 7 amps. USB-C PD is currently (ha!) limited to 3 or 5 amps. So it’s not as simple as just hooking up a USB-C power adapter. I’m putting together a USB PD sink module that gets 20V/5A from an adapter with a buck module that converts to 12V/8 Amps without a fan. It took some searching, ordering modules from China, waiting, and some electronics expertise. So far I’ve tested it with 50 Watt resistive load and it regulates to 12V within 2-3%. I’ve ordered the proper power connector, and am prepared to add the specific resister required for the Dreamstation to recognize the supply.

We’ll see how it handles the pump/motor in the CPAP, but I’m hopeful it will work. Overall, with an 87W USB-C power adapter, it’s not much smaller than the brick, but the adapter and 5-Amp USB-C cable can serve double duty during travel.

[HiGreg]

Just a simple follow up. A great source of information on CPAP on batteries is this thread by CapnLoki: viewtopic/t114012/Choosing-a-Battery.html

Edit to add: also, every listed xPAP machine in the ResMed Battery Guide shows that they stay under 2A if using DC-DC converter and no heat/humidifier: https://www.resmed.com/us/dam/documents ... lo_eng.pdf

Also, elsewhere on the board is this:

"[...DreamStation...] use[s] the same type of plug (same dimensions, but right angled) as the A10 but they use a simple 20k ohm resistor to +12V on the center pin.
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.
Outside barrel of plug is Ground
Inside Barrel of plug is Positive
Center pin is positive."

Note that the standard size resistor in the required range is 22K. i measured 25k between center pin and inside barrel on my power supply.

The battery tests from CapnLoki indicate that without heater or humidfier, the DreamStation will stay below 2A of current at 12V. I have found a module that can be programmed to a fixed 12V and max 3A. This should be sufficient for powering the DreamStation with a very simple (and small) cable. After removing USBA connector (not needed for this application), the module looks to be about 13x6mmx25mm. My plan is to hook it up to a 7.4mm barrel connector with pigtail and the resistor, then shrinkwrap the whole thing. Super tiny! I'll see in a month (as parts come in) if this works.

[Rickshaw530]

I have found a module that can be programmed to a fixed 12V and max 3A. This should be sufficient for powering the DreamStation with a very simple (and small) cable. After removing USBA connector (not needed for this application), the module looks to be about 13x6mmx25mm. My plan is to hook it up to a 7.4mm barrel connector with pigtail and the resistor, then shrinkwrap the whole thing. Super tiny! I'll see in a month (as parts come in) if this works.

Did you build it? What was the outcome?

[drbirdman03]

I am also interested in finding out if this worked for the OP.
I am going long-distance hiking this summer and am trying to find a way to use the CPAP while on the trail, and a solar rechargeable usb-c PD bank seems like a great option, in terms of power:weight ratio. Without the need for the inverter or or other irrelevant technology, the PD powerbank is very lightweight, compared to other "solar generator" options, like rockpals, goal zero, jackery, etc.

I have ordered the materials to try exactly this too, and I will try to post when I get it all put together.

[Jrperki]

I had a Z1 travel CPAP that I ran off a USB PD power brick and a cable I made with a USB PD trigger chip. It finally gave up after several years and I just got a Z2. I haven't had a chance to unbox it yet but I think the same cable will work. The pd power brick is a $37 Miady 26800mAh PD Portable Charger Power Bank with 30W USB C Output for Nintendo Switch. The trigger adapter $7 was a Acxico 1Pcs Type-C USB-C PD2.0 3.0 to DC USB Decoy Fast Charge Trigger Poll Detector Charging Module ZYPDS Ultra-Mini Single Function. I ran it at 15V to get sufficient current to power the Z1. I could have purchased the parts cheaper if I ordered them from China. This solution will probably void ALL warranties but I don't care because it is significantly lighter and cheaper than any other solution I have found. I can run my cpap for at least 2 nights and use the same power brick to charge my phone and camera batteries. I chose the 26800 size brick because it is the largest allowed on all the airlines I checked.

[Next362]

I did this shortly after getting my original Dreamstation (Before this post), there is nothing special about the power requirements, but, if I remember correctly the barrel connector has 3 connections. 2 + 12v wires and 1 -, the positive need to have a small resistor between the 2 + wire to work properly (like any Laptop that has a 3 wire connector that gives a message about an invalid power adapter on boot, they do the same "trick" a specific resistor on the 2 positive lines, that resistance is the "ID" that tells the device it's legit). I don't know if it will work without this, but I just bought the Auto adapter and modified the input from a car connector to a hardware in a tiny box with a USB PD trigger for 20v @3a (60w) and a stepdown converter for 12v stabilized output (this creates a bit of waste power, but the 12v @3a PD Profile (36w) will absolutely not work. I built it for travel, it will not work with the heater or humidification tank, so those need to be removed for using it, but it works in a power outage or travelling lite with a 20,000ah USB PD 60W battery for ~10 hours, and works with any USB Wall wart that can do 20v @3a. The parts can be purchased on amazon to whip it together in about 15min for about $60. Having a baseline electronics, soldering, and PD knowledge is all you really need.

Power cord (that you need to add a resistor to): https://www.amazon.com/gp/product/B085L ... UTF8&psc=1
Power cord (Higher cost but no need to wire a resistor, you can cut off the big choke near the auto plug): https://www.amazon.com/gp/product/B07G7 ... UTF8&psc=1

USB Triggers:
Enclosed with Barrel Jack: https://www.amazon.com/gp/product/B07SJ ... UTF8&psc=1
Bare board (would need attached to something, or enclosed in Hotglue/epoxy): https://www.amazon.com/gp/product/B081Y ... UTF8&psc=1

20v to 12v stepdown: https://www.amazon.com/Converter-Voltag ... 9GKB73QQW9

Enclosure big enough for all this and wires: https://www.amazon.com/gp/product/B0107 ... UTF8&psc=1