ResMed S9 and external power/UPS supply

mldenison wrote:I purchased a DC power pack (for another purpose). I noticed they have some nifty AC Power packs as well.

I wonder if they would be more suitable than a UPS designed for coputers and the like?

http://www.powerportstore.com/power.htm ... 20SUPPLIES

Mort

Yes, these are what people are building here, trying to do it for a lot less money. The battery is the most expensive part at $80 to $100, and that is not included. The converter can be purchased for $45 for the modified sine wave that S-9 humidifier can run on. The battery box is about $20, the trickle charger is about $20 and the lighter plug also around $20. The unit is nice that it is all attached together, but w/o a handle, it would be hard for some to move at around 50 lbs. It would be more efficient with-out converting it to ac then back to dc and Resmed can't seem to get one to the market. Maybe someday they will, but people are trying to get a back-up power source for possible power outages this winter.john

jlk wrote:Here's my take on the thing, this is the brick opened up,(notice the white dog hair at the 9:00 oclock position, that would be Max) the white wire has 24 volts on it, the red wire is the ground, and the black wire has 3 volts on it, with the unit running or not. I think the 3 volt wire turns a solenoid (electrical switch) on inside the S-9 to allow it to power up. it's labeled "res bus" on the circuit board, meaning "signal wire".

I can't tell from the pic. Are the three wires soldered to the pc board, or plugged onto connectors? If the latter, how about disconnecting the 3 volt wire and substitute another 3 volt source such as a couple of 1.5 volt batteries and see if that makes the unit work. If it does then it would be a simple matter to come up with a 3 volt source from the main battery configuration I discussed earlier.

Ideally, if you had an oscilloscope you could get a picture of the 3 volt line while the unit is switched on & off and while it's running. That way you could see if there's actually some sort of varying signal on it, or if it's just a steady 3 volt signal. I can't fathom any need for a varying signal back to the power supply except to foil the use of ordinary 24 volt power supplies. Or, maybe it's there to supply standby power to keep the memory live while the 24 volt part of the PS shuts down completely to eliminate a 'phantom' load. Some countries, and companies, are more conscious about reducing power consumption than typically you find in the US.

idamtnboy wrote:I can't fathom any need for a varying signal back to the power supply except to foil the use of ordinary 24 volt power supplies.

Keep in mind that CPAP kit is supposed to be plug and play as far as possible for users who have no skill or interest in how it works.

Resmed has two mains power adapters currently available. There is the standard 90W supplied as part of the normal delivery package which can power the S9 + H5i, and a smaller 30W one which will power an S9 only and as far as I can tell is intended for use in-flight from at-seat mains power outlets (and similar situations), which may be energy limited.

The extra line may be related to handshaking between S9 and the power adapter to determine the class of power supply attached, so that the S9 does not attempt to deliver power to the H5i if the attached power source does not have the capacity to do so.

From a plug and play point of view, that would be very sensible thing to do. There was a lot of bitching here about the DC-12 adapter for the S8, but it was a very good plug and play solution which addressed a wide range of possible issues with battery powering across a broad spectrum of use cases (including use by long distance truckers), and made it as fool-proof as possible.

Cheers,

Bill

idamtnboy wrote:

jlk wrote:Here's my take on the thing, this is the brick opened up,(notice the white dog hair at the 9:00 oclock position, that would be Max) the white wire has 24 volts on it, the red wire is the ground, and the black wire has 3 volts on it, with the unit running or not. I think the 3 volt wire turns a solenoid (electrical switch) on inside the S-9 to allow it to power up. it's labeled "res bus" on the circuit board, meaning "signal wire".

I can't tell from the pic. Are the three wires soldered to the pc board, or plugged onto connectors? If the latter, how about disconnecting the 3 volt wire and substitute another 3 volt source such as a couple of 1.5 volt batteries and see if that makes the unit work. If it does then it would be a simple matter to come up with a 3 volt source from the main battery configuration I discussed earlier.
Ideally, if you had an oscilloscope you could get a picture of the 3 volt line while the unit is switched on & off and while it's running. That way you could see if there's actually some sort of varying signal on it, or if it's just a steady 3 volt signal. I can't fathom any need for a varying signal back to the power supply except to foil the use of ordinary 24 volt power supplies. Or, maybe it's there to supply standby power to keep the memory live while the 24 volt part of the PS shuts down completely to eliminate a 'phantom' load. Some countries, and companies, are more conscious about reducing power consumption than typically you find in the US.

The wires are soldered to the board, but there is plenty of room to safely de-solder them.
I don't have an oscilliscope but that would be a good test also to see exactly what is going on there. I don't know if the designers would go as far as a varying signal or not. It suppose it would be pretty easy to do in the design phase if they wanted. john

billbolton wrote:

idamtnboy wrote:I can't fathom any need for a varying signal back to the power supply except to foil the use of ordinary 24 volt power supplies.

Keep in mind that CPAP kit is supposed to be plug and play as far as possible for users who have no skill or interest in how it works.

Resmed has two mains power adapters currently available. There is the standard 90W supplied as part of the normal delivery package which can power the S9 + H5i, and a smaller 30W one which will power an S9 only and as far as I can tell is intended for use in-flight from at-seat mains power outlets (and similar situations), which may be energy limited.

The extra line may be related to handshaking between S9 and the power adapter to determine the class of power supply attached, so that the S9 does not attempt to deliver power to the H5i if the attached power source does not have the capacity to do so.

From a plug and play point of view, that would be very sensible thing to do. There was a lot of bitching here about the DC-12 adapter for the S8, but it was a very good plug and play solution which addressed a wide range of possible issues with battery powering across a broad spectrum of use cases (including use by long distance truckers), and made it as fool-proof as possible.

Cheers,

Bill

Resmed said they were putting a 12 volt converter out last summer. There are people that expected that and now with winter coming want another option to power their S-9. That is what is wanted, a plug and play 12 volt power supply. There are people waiting for the third option that was supposed to be available last summer. When will it be available? That is why we are looking at options to pick-up where Resmed left off, If they can't/won't do it, we 'll figure out how to. john

billbolton wrote:

idamtnboy wrote:I can't fathom any need for a varying signal back to the power supply except to foil the use of ordinary 24 volt power supplies.

Keep in mind that CPAP kit is supposed to be plug and play as far as possible for users who have no skill or interest in how it works.

No argument about that from me! Some of us are just trying to figure out if we can come up with a solution for a battery backup in the absence of a desired unit from Resmed. If we come up with a workable solution I'd be willing to put one together for someone who wants one but needs it to be as 'plug and play' as practical. As you know, the goal is to come up with a solution that uses battery power as efficiently as possible. I'm sure Resmed's current solution using an inverter and a deep cycle battery isn't simple plug and play for many people.

Anyone have a DC- 24 volt power supply for the Resmed VPAP AUTO 25 or VPAP ST that they are willing to sell, please pm me. john

I love it when you boys put your heads together.
John your right, we have been waiting for a Resmed solution but they said in Aug, then in Nov. Now it's December.
Your also right about the plug and play.....nothing to complicated.

If the power goes out in the night I want to be able to sleep in my bed, not sitting up on the sofa.
I nearly go into a panic just thinking about the power going out.
We did get a small generator, but that intail going out to the garage, using dolly to bring it to back of house.
Finding the right extention cord in the drawer where there are at least 15 cords.
Plu everything in then stand outside and try to pull the cord hard enough (don't forget the choke) to start the dam thing.

By the time I do this the power will likely be back on and I'll be mad as hell.

jazzer4 wrote:By the time I do this the power will likely be back on and I'll be mad as hell.

Plus, if this happens about 4 AM you'll be so awake by then you wouldn't get back to sleep anyway!

I'm bumping this topic. We (as in you guys) have been thinking about it I hope

Once again people are posting about power outages.
RESMED ARE YOU LISTENING?

Hello, something was suppose to be out for this in Aug, Nov, then Dec. STILL NOTHING.....RESMED ARE YOU THERE??

https://www.cpap.com/productpage/DC-Pow ... Bipap.html

I think this power supply is the same connector that the S-9 needs, it also is 24 volts. Anyone have one of these in their possession? john

What do you need off it? I have one.

I am very curious about how much voltage is on the small pin in the connector and does it fit into the S-9. There has been a lot of discussion about where to get a connector that will plug into the S-9. I was reading a post about John B. Fisher's battery set-up and noticed the connector appears exactly like what we have been looking for. To think it may have been right under our nose the whole time. Your dc set-up is converting 12 volt current to 24 volts as far as I can tell, Is that correct? Do you know anyone you physically see that has an S-9 that you could check if the power supply you have will plug into the S-9, even unpowered? I think we may be onto something that Resmed has been promising for months now and not delivered. john

I don't have access to an S9