02-11-2016, 10:17 PM
(This post was last modified: 02-12-2016, 12:03 AM by justMongo.)
Two issues with using a computer UPS.
1) There battery is a SLA battery with much less A-Hr capacity than you can get for the same money.
-- The UPS just will not last the night.
2) Many UPS use a stepped Sine approximation when running on backup battery.
-- This does not work for some newer computer power supplies with active power factor correction.
-- For the same reason, it may not work with the power brick for a CPAP.
Then you have the double conversion mentioned by Sleepster. Wasted energy.
I would bet that the PR 12V cable also has a reverse polarity protection diode -- possibly a Schottky for low forward drop.
There are different solutions for different scenarios. For camping -- that's one scenario.
For home backup, the most elegant solution I have seen was proposed by, I think, OMMOHY.
A big 12 Volt SLA scooter battery, a switch mode power supply for charge and float charge; and a Super PWRgate PG40s Schottky diode bridge to autoswitch the load from Power supply to Battery; and permit recharge and float charge.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
I've found that the A10 will run from a +24 volt power supply (non-ResMed) when the center pin is connected to +3.3 volts thru a 2.7k ohm resistor. I use a +3.3 volt three-terminal voltage regulator fed from the +24 volt power supply. The resistor functions as a pull-up resistor to +3.3 volts and tells the cpap the power rating of the supply. I've tested this on two units.
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.