My battery backup setup

[Sleepster]

Would you see if you can find the post showing the circuit? I looked but found nothing.

I think it's this one, but I'd have to wade through the whole thread to be sure. And even then, I'd be much more confident simply buying the ResMed converter.

http://www.apneaboard.com/forums/Thread-...#pid165303

[vk3hjq]

This works on an S9 Autoset, just by adding +3.3V & 2.7K resistor to pin 3

Pin 1 + 24V (S9 White wire)
Pin 2 - GRN  (S9 Braid wire)
Pin 3 + 3.3V Sense pin (small one) (S9 Black wire)

John vk3hjq





justMongo Actually that circuit should not generate EMI.  It's a linear series regulator; not a switcher.  We see them right close to the resmed power bricks because they are switchers.  
Thanks Mongo for the answer about the EMI and for the photo of the cores in use.

I couldn't figure out WHERE any EMI could be coming from, and, even if it was there, how would it affect the ResMed machine, which is, essentially, just a fancy fan?

I guess EMI can affect the cellular modem, but, even so, the ResMed device itself, having a 3-phase brushless motor inside, certainly generates more noise than does this linear power supply.

I updated the graphic, and corrected the attribution to reflect that it's Steve's baby. We're helping out on the graphic making it easy for others to assimilate. I think the fact we drew something that "looks" like discrete components is nice in that a schematic would turn some people off (who don't know how to read them anyway).

On the fuse, it looks like the ResMed supplies max out at 3.75 amps, so, how does a 10 amp quick-blow fuse sound to you and to Steve?

Steve: Any update on the testing of the voltage?

The MOST IMPORTANT thing is the voltage on the ResMed power bus.
If we use batteries, they can fluctuate between, oh, I don't know, maybe 10 volts each to 15 volts each? That's 20 to 30 volts, which is ok for the regulator (just barely); but what about the ResMed device?

[georgelewisray]

OFFGRID - ResMEd AutoSense or VAuto - OFFGRID

(1) LESS $100 ::: Works GREAT ! ! ! , super easy just needs cigarette lighter outlet.
ResMed sells a 12VDC power supply with cigarette lighter plug. (part# 37297)
-- I HATE the darn cigarette lighter plugs because they often wiggle and lose connection/power , , so I end up needing to somehow provide a string lashing to keep tension on plug so it stays secure/connected.
-- The humidifier is a big power draw so I went from MAX humid to NO humid when in teardrop trailer with one little 12V (24 series) deep cycle battery and battery did OK and I did OK with no added humidity.

(2) More than $100 , More complicated , Works GREAT .
Inverters: I like the Victron Brand as they are pure sine power, seem high quality and provide very modern features.
-- Complication of setting up batteries and chargers is not for everybody.
-- Note: $50 BlueTooth smart dongle allows phone App to monitor inverter. We have the 1200W big inverter in shed with batteries , well pump and generators. From the cabin to the shed is about 20ft and I can be in cabin anywhere near the wall that is close to the shed and use the app to check battery voltage and inverter status and watch power consumption level.
-- Note: Victron sold worldwide so the type plug for USA is part of model # . i.e.NEMA 5-15R
Small stuff: $125-ish 375 watt, Victron Energy Phoenix True Sine Wave Inverter 12/375 120V VE.Direct NEMA 5-15R
-
Big Stuff: $400-ish 1200 watt, Victron Energy Phoenix True Sine Wave Inverter 12/1200 120V VE.Direct NEMA 5-15R
-
The 1200 Watt will: (1)  run our hot water pot for coffee tea (just will run it) , (2) run our 3qt instantPot for cooking.

******

   

[vk3hjq]

   

You can get these off ebay very cheap
____________________________________________________________

This works on an S9 Autoset, just by adding +3.3V & 2.7K resistor to pin 3

Pin 1 + 24V (S9 White wire)
Pin 2 - GRN  (S9 Braid wire)
Pin 3 + 3.3V Sense pin (small one) (S9 Black wire)

John vk3hjq





justMongo Actually that circuit should not generate EMI.  It's a linear series regulator; not a switcher.  We see them right close to the resmed power bricks because they are switchers.  
Thanks Mongo for the answer about the EMI and for the photo of the cores in use.

I couldn't figure out WHERE any EMI could be coming from, and, even if it was there, how would it affect the ResMed machine, which is, essentially, just a fancy fan?

I guess EMI can affect the cellular modem, but, even so, the ResMed device itself, having a 3-phase brushless motor inside, certainly generates more noise than does this linear power supply.

I updated the graphic, and corrected the attribution to reflect that it's Steve's baby. We're helping out on the graphic making it easy for others to assimilate. I think the fact we drew something that "looks" like discrete components is nice in that a schematic would turn some people off (who don't know how to read them anyway).

On the fuse, it looks like the ResMed supplies max out at 3.75 amps, so, how does a 10 amp quick-blow fuse sound to you and to Steve?

Steve: Any update on the testing of the voltage?

The MOST IMPORTANT thing is the voltage on the ResMed power bus.
If we use batteries, they can fluctuate between, oh, I don't know, maybe 10 volts each to 15 volts each? That's 20 to 30 volts, which is ok for the regulator (just barely); but what about the ResMed device?

[vimo1970]

Greetings @Sdb7802 wondering if you could help me diagnose what could be wrong possibly with my power adapter for a 5 year old Autoset S9 (Yes I know it's dated but don't want to spend on a new one yet as this was fine for me) I got the typical Check Reamed 30/90W power adapter message a few weeks ago. That did go away after some fiddling with the connector but it's now back again and not going away. I did check voltages, both on the pins and later on various points on the PCB (could find 3 places I could measure in the back) and they were fine at 24V and 3.3V. Further the 3.3Vpin to ground resistance (disconnected) shows me around 2.75K increasing slowly to about 2.86K (not sure of that is that some capacitor in parallel charging slowly?) which seems at the limit of the 5% tolerance but should be Ok I guess. Yet the message refuses to go away. I also tried creating my own 3.3V supply (cutting up the power adapter cord as a last resort to bypass the earlier 3.3V) with a LM1117 3.3 with a 2.7K in series taking its input off a 5V adapter. That also doesn't seem to help. You mentioned about some other regulator not working, do you think the LM1117 3.3 would have an issue as well?

I did think I could just order a replacement supply they are still a tad expensive (20% cost of a new machine), and those are.unfortunately non returnable in India. And I am wondering now after all these experiments if the problem is actually in the machine or its f/w, not the adapter so don't want to throw away money getting an adapter that won't help. 
Any pointers will be most helpful. Thanks in advance.

[vimo1970]

Greetings @Sdb7802 wondering if you could help me diagnose what could be wrong possibly with my power adapter for a 5 year old Autoset S9 (Yes I know it's dated but don't want to spend on a new one yet as this was fine for me) I got the typical Check Reamed 30/90W power adapter message a few weeks ago. That did go away after some fiddling with the connector but it's now back again and not going away. I did check voltages, both on the pins and later on various points on the PCB (could find 3 places I could measure in the back) and they were fine at 24V and 3.3V. Further the 3.3Vpin to ground resistance (disconnected) shows me around 2.75K increasing slowly to about 2.86K (not sure of that is that some capacitor in parallel charging slowly?) which seems at the limit of the 5% tolerance but should be Ok I guess. Yet the message refuses to go away. I also tried creating my own 3.3V supply (cutting up the power adapter cord as a last resort to bypass the earlier 3.3V) with a LM1117 3.3 with a 2.7K in series taking its input off a 5V adapter. That also doesn't seem to help. You mentioned about some other regulator not working, do you think the LM1117 3.3 would have an issue as well?

I did think I could just order a replacement supply they are still a tad expensive (20% cost of a new machine), and those are.unfortunately non returnable in India. And I am wondering now after all these experiments if the problem is actually in the machine or its f/w, not the adapter so don't want to throw away money getting an adapter that won't help. 
Any pointers will be most helpful. Thanks in advance.

So just to clarify I set up the connection something like this graphic I found on this thread. Except I have used a separate 5V supply and an LM1117 3.3 V regulator instead of the Buck converter shown here. And of course have wired the 3.3V regulator ground back to the braid of the cable so it shares the ground with the 24V. But no luck with getting the machine to accept the power supply.

---

Actually I realise that in my power adapter cable the braid appeared to be the common ground for the 3.3V as well as the 24V, the black was the 3.3V through the 2.7K and the white was the original 24V (actually measured as about 24.5V o/c which should be acceptable i guess)

[timpani]

I almost went with a 100Ah AGM battery but I decided to go with one of those lithium-ion power packs. I could run my PR DS1 for a week since I was using the DC adapter (no power loss due to DC, AC, back to DC) plus I can drain it right down till it's protection circuit cuts it off. It's much more portable too. It can hold over 95% of it's charge for 6 months and I don't need a tender. I'm a little concerned about the AGM route, even though it's "sealed" lead-acid, that there are still some potentially toxic outgassing.

[speed3914]

I used to have the battery and power cord setup for my DS1 as a backup. Now I have a whole house generator system so it's not an issue.

[vimo1970]

This works on an S9 Autoset, just by adding +3.3V & 2.7K resistor to pin 3

Pin 1 + 24V (S9 White wire)
Pin 2 - GRN  (S9 Braid wire)
Pin 3 + 3.3V Sense pin (small one) (S9 Black wire)

John vk3hjq





justMongo Actually that circuit should not generate EMI.  It's a linear series regulator; not a switcher.  We see them right close to the resmed power bricks because they are switchers.  
Thanks Mongo for the answer about the EMI and for the photo of the cores in use.

I couldn't figure out WHERE any EMI could be coming from, and, even if it was there, how would it affect the ResMed machine, which is, essentially, just a fancy fan?

I guess EMI can affect the cellular modem, but, even so, the ResMed device itself, having a 3-phase brushless motor inside, certainly generates more noise than does this linear power supply.

I updated the graphic, and corrected the attribution to reflect that it's Steve's baby. We're helping out on the graphic making it easy for others to assimilate. I think the fact we drew something that "looks" like discrete components is nice in that a schematic would turn some people off (who don't know how to read them anyway).

On the fuse, it looks like the ResMed supplies max out at 3.75 amps, so, how does a 10 amp quick-blow fuse sound to you and to Steve?

Steve: Any update on the testing of the voltage?

The MOST IMPORTANT thing is the voltage on the ResMed power bus.
If we use batteries, they can fluctuate between, oh, I don't know, maybe 10 volts each to 15 volts each? That's 20 to 30 volts, which is ok for the regulator (just barely); but what about the ResMed device?

Hi John 
As I mentioned in another post I used the same connections when trying to solve issues with my Resmed Auto S9 power adapter.
Though voltages are checking out fine 24V 3.3V and the sense to ground resistance comes in at very close to 2.7K (2.75K due to tolerance) I'm still getting the same Check Resmed 30/90W power adapter message. 
Only thing is I am using an LM1117 3.3 not a Buck converter. The LM1117 itself takes its inputs from a 5V adapter. 
I noticed in some posts on this thread about connecting a 47K from the 24V to the sense pin, to get 1.8V at startup for a brief while. Is that something I need to do in addition to the 2.7K in series with the 3.3V sense pin?

[vk3hjq]

Hi there,

Correction on this circuit digram, DC-DC Buck Step Down Converter Regulator Module 3.3V

Should read
Pin 3 Black not Braid
Pin 2 Braid not Black

John vk3hjq