12 volt battery adapter for Philips Respironics CPAP DreamStation

[Tech6]

Hi! 

This is my first post and hopefully someone has some experience on this matter. I am planning to build an adapter in order to connect my Philips Respironics CPAP DreamStation to a 12 volt battery, but as I read somewhere there is a voltage divider inside the connector which set the voltage on the center pin of the connector - or sense pin. Has anyone dealt with this?

[Tech6]

I forgot to add a quick draw on both the PSU and the cable connector.

[mnemon81]

I recently bought this car adapter ( https://www.amazon.co.uk/dp/B0B92X8KNQ ) which I am testing with the power station, so far so good. You could combine it with https://www.amazon.co.uk/Magiin-Cigarett...B0787TXTSY and you are sorted

[Tech6]

I recently bought this car adapter "link" which I am testing with the power station, so far so good. You could combine it with "link" and you are sorted

Thank you so much mnemon81! 

Yes, these will do the job and I may end up purchasing one of these, but I rather build one myself if someone kindly could share the resistor values inside the connector.

[mnemon81]

Ok, so i took car adapter apart and there is no resistor, however when I measured the resistance between both ends it showed 24.89 kilo ohm which would indicate some resistance at the tip which plugs into the dreamstation

[Tech6]

Ok, so i took car adapter apart and there is no resistor, however when I measured the resistance between both ends it showed 24.89 kilo ohm which would indicate some resistance at the tip which plugs into the dreamstation

Very kind of you mnemon81! 

I will make a quick schematic with the 24.89 kohm resistor tomorrow Saturday when I wake up just to be sure that I got it right. Thanks again! ? 

[Tech6]

Hi again mnemon8!


Now, this new drawing includes the car adapter and a series resistor as well – placed as I understand from your post – but there are a few points that would be good to know and as follow below.

• Are there only two wires coming into the car adapter or are there three with two of them, plus 12 and sense wire, joined together and the third to minus as in my schematic.
  
  
• Could the inside of the center tip of the car adapter hide a resistor? Of course there must be, if that would be the case, one wire that connects +12 volt directly to the DC-plug inner ring.
  
  
• Could you please also measure the resistance between minus – outer ring of the DC-plug – to center pin of the DC-plug and with the probe still on minus also the inner ring?
  
  Thank you! 
  
  
  
  

[mnemon81]

Hiya

There is only 2 wires coming from car plug. Dreamstation plug is sealed so I can only assume that resistor ≈ 25 kohm is contained within that plug between the plus and center pin.

If you search for " Dreamstation 25 kohm " in google, it shows few posts with people resolving the issue, including pictures

[Tech6]

Hiya

There is only 2 wires coming from car plug. Dreamstation plug is sealed so I can only assume that resistor ≈ 25 kohm is contained within that plug between the plus and center pin.

If you search for "  Dreamstation 25 kohm " in google, it shows few posts with people resolving the issue, including pictures

Thank you so much for all your help mnemon81! 

I will do a search on the 25k resistor right away!

[Apneaway]

Not sure if it is for home or car use. I use my unit with an UPS at home. This not only can provide spike protection to the unit but also power when there's a power outage. Just need to get an UPS that the beeper is able to be disabled. I believe I can use an inverter if I need to use it in my car.