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My battery backup setup
RE: My battery backup setup
Cleaning it up...

[Image: 2hxmwr9.jpg]
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RE: My battery backup setup
(06-16-2016, 09:23 PM)justMongo Wrote: The bridge is incorrectly hooked up; and the resistor should be 2.7K

Ooopps. My mistake.

Thanks Mongo!

That's what I love about peer review!
You were able to take my schematic binary and update it without having to start from scratch!

That's wonderful!

BTW, I couldn't get angles in the wires like you did, but otherwise, here's the updated 30KB binary DipTrace schematic1.dch and schematic2.dch.
[Image: tCiyIo.gif]
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RE: My battery backup setup
(06-12-2016, 10:53 PM)sdb7802 Wrote: I'm going to use the two 12V 8AH batteries in my fairly new UPS to test the circuit. I've ordered some Schottky diodes, so hopefully I can run the test by the end of the week.

Completed tests successfully.

With A10 set to 10cm fixed (hum & hose heater off) and mask blocked off except vent holes, the runtimes were:

33.5 hrs without diodes.
32 hrs with schottky diode bridge.

That's using two 12V 8Ah batteries in series. The A10 draws about 0.25A with these settings. The runtime would be less for actual use, but IMHO the allowable input voltage range of the A10 would not preclude direct connection to a 24V battery set. Or through a schottky diode bridge.

I tried the following schottky diodes with success:

OnSemi 80SQ045N (8A, 45V)
Vishay MBR1045 (10A, 45V)

A couple of others that should work are:

Fairchild SB1245 (12A, 45V)
MCC SR1045 (10A, 45V)


As far as changing the 3.3 volt regulator to a LM2936Z-3.3/NOPB for its greater breakdown voltage; the input cap can stay the same (0.1uF 50V ceramic), but the output cap must be changed to a 22uF 10V tantalum. The output capacitor must have an ESR between 0.3 to 8 ohm for regulator stability. Two suitable parts that are readily available online are:

AVX TAP226K010SCS
KEMET T350E226K010AT

In summary, we are go for liftoff. I would label the diode bridge as optional.
Just my personal opinion.  My posts are not medical advice or a statement of fact.  Please consult a qualified physician or other qualified medical personnel.  Please comply with all applicable laws, codes, regulations, and protocols.
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RE: My battery backup setup
Has anyone thought of using a simple resistive voltage divider instead of the 3.3V regulator? For example, if we can determine the actual resistance of the internal "pull-down" used inside the S10 device, you can build a suitable divider network that will put the correct VOLTAGE at the sense pin.

This would simplify the setup tremendously. You would basically float the sense pin between two resistors. When it was plugged into the unit, the internal resistance would be added to the voltage divider and the voltage would be at the level that the unit expects.

All you would need to do is determine what the voltage is at the sense pin for a 90W supply (after the sense resistor), and you could build a simple divider to do the job.

The amount of current that the sense pin draws will determine the values of the resistors you would have to use (just 2 of them).

Dave Cameron
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RE: My battery backup setup
justMongo -- At least you could have purchased an American boat to go with your Australian xPAP.

Have you thought about hardwiring "MAXI Fuse Holders with Ring terminals and 75 Amp Powerpole Connectors" and using a battery box to prevent accidental discharges and potential fires?

"The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane." -- Marcus Aurelius
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RE: My battery backup setup
There are very few accidental discharges. There are lots of negligent discharges. They are best prevented by treating every firearm as if it is loaded; never allowing the muzzle to cover something you are not willing to destroy; keeping your finger off the trigger until your sights are on the target and you are ready to fire; and always be sure of your target and what lies beyond it.

OMMOHY
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RE: My battery backup setup
(06-14-2016, 11:16 PM)sdb7802 Wrote: I should probably point out that Philips Respironics has already joined the ResMed proprietary club with the introduction of the DreamStation line.

They use they same type of plug (same dimensions, but right angled) as the A10 but they use a simple 100k ohm resistor to +12V on the center pin.

Correction: Make that 20K ohm.

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.
Just my personal opinion.  My posts are not medical advice or a statement of fact.  Please consult a qualified physician or other qualified medical personnel.  Please comply with all applicable laws, codes, regulations, and protocols.
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RE: My battery backup setup
I made a post a few weeks back with all the actual values that didnt seem to make the forum.... Now I lost the paper, but if there is interest I will redo the testing.

So I was able to get a working setup with a cheap 12V-24V 10A converter from E-bay, and using a 47K ohm resistor between the +24 and the center pin. This provided the right voltage at startup so the machine would operate with all of its features, and I have not noted any issues with running it that way. There is no diode bridge or regulator involved.

I pulled the power cord from a old Dell laptop to get the connector and cable.

I did all the probing with the factory AC adapter, and determined what the resistance was between the 3.3V volt supply and the center pin. By grounding the pin, I determined that the resistance is right about 2.5 k ohms for the adapter I have.

I then plugged it in and watched the voltage when the machine booted up, and recorded the voltage to determine what the voltage it was looking for on boot. It was right around 1.8V (I will have to probe again for the two values). The machine seems to have a fixed resistance, and then switches on another resistor to test the adapter, then goes back to the fixed, and then starts some sort of data stream.

I first tried to build a voltage divider to lower the voltage on the pin. I could never get it to work quite right. I then just hooked up a 22K resistor in series, and used a 47K variable to find the range at which the machine would boot with all its features. I found that using a single 47K between 24V and the center pin yielded exactly what I needed - about 1.8V on the startup.

I have run this setup on two machines, and used it for 6 nights hooked to a 250aH 12V battery in my trailer. Worked fine every time.

Overall I am impressed at how efficient this setup is. I compared it to my friends "factory" DC adapter, and this one uses about 10% less power. The DC-DC converter I am using is listed at 96% efficiency.



(06-27-2016, 05:52 PM)ve7ltd Wrote: Has anyone thought of using a simple resistive voltage divider instead of the 3.3V regulator? For example, if we can determine the actual resistance of the internal "pull-down" used inside the S10 device, you can build a suitable divider network that will put the correct VOLTAGE at the sense pin.

This would simplify the setup tremendously. You would basically float the sense pin between two resistors. When it was plugged into the unit, the internal resistance would be added to the voltage divider and the voltage would be at the level that the unit expects.

All you would need to do is determine what the voltage is at the sense pin for a 90W supply (after the sense resistor), and you could build a simple divider to do the job.

The amount of current that the sense pin draws will determine the values of the resistors you would have to use (just 2 of them).

Dave Cameron

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RE: My battery backup setup
Just had an idea. Purchase my own ac power supply, cut the output cord and wire it such that a switch in one position would be normal use. Throw the switch the other direction, small inverter to power only id handshaking, with plug for powering off 24vdc power scooter batteries. Would require a dpdt switch, prefer slide switch as toggle might get bumped in the night. Power draw on inverter would be minimal, as it is only powering handshake use, verses trying to power everything from inverter.

Any thoughts from others out there. This way, if you prefer humidity etc, if you have enough battery, no problem. You are not going to burn up resmed 12-24v converter.

I believe such an idea would work.

This was written prior to seeing the schematic and comments above. Thank those involved for the information.

Can anyone tell me if this is the connector required to plug into an AirSense 10 or AirCurve 10?

<link removed>

I also foumd same connector on ebay with cord for less money



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RE: My battery backup setup
I believe this is the simplest circuit, if I understand you correctly.
   
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