[Equipment] 12VDC adapter

[jweste749]

Has any one tried to use a 12VDC to 120VAC 300W inverter using a modified wave form(squared sine wave) to power a System One CPAP machine

[PaulaO2]

Try this thread:
http://www.apneaboard.com/forums/Thread-...r-goes-out

and this one
http://www.apneaboard.com/forums/Thread-...or-camping

oh, and this one:
http://www.apneaboard.com/forums/Thread-...ane-season

[archangle]

As far as I can tell, Respironics has never given any guidance on whether you can use any kind of inverter on their machines. Some of the online sellers say you can use an MSW supply with the PRS1 machines.

ResMed says S9 machines are safe for MSW, but MSW may damage an S8 humidifier. The S8 blower unit is safe with MSW as long as the humidifier is not used. They say MSW will damage an S8 humidifier.

I think (THINK) PRS1 machines are probably OK with MSW, since they use an external power brick to power both the blower and humidifier. The blower and humidifier and heated hose run off of DC from the power brick.

I wouldn't use MSW on the humidifier for Legacy or M series machines.

[Bernie]

As far as I can tell, Respironics has never given any guidance on whether you can use any kind of inverter on their machines. Some of the online sellers say you can use an MSW supply with the PRS1 machines.

ResMed says S9 machines are safe for MSW, but MSW may damage an S8 humidifier. The S8 blower unit is safe with MSW as long as the humidifier is not used. They say MSW will damage an S8 humidifier.

I think (THINK) PRS1 machines are probably OK with MSW, since they use an external power brick to power both the blower and humidifier. The blower and humidifier and heated hose run off of DC from the power brick.

I wouldn't use MSW on the humidifier for Legacy or M series machines.

What is the actual output voltage (under load) of the power brick that is used with the ResMed S9 and H5i humidifier? It seems to me that I read somewhere that the voltage was 24V DC and elsewhere I read that it is 12V DC. Could a 24V or a 12V (as the case may be) storage battery be used directly as an emergency supply instead of having to go through the ResMed regulator adapter?

[PaulaO2]

Or do what I do. I have a deep cycle gel battery, an outlet that is two clips (one for each terminal) that ends in the usual 'cigarette lighter' hole. Then I have an inverter I use for my laptop while in the truck (and not driving! LOL). I plug the inverter into the outlet, going from 12v to 120v. When the power goes out, I plug the CPAP into the inverter. Done. No extra money going to Resmed for a 'special' adapter. I don't use the humidifier in that situation because any device that is designed to generate heat is going to drain a battery really fast.

[Bernie]

Or do what I do. I have a deep cycle gel battery, an outlet that is two clips (one for each terminal) that ends in the usual 'cigarette lighter' hole. Then I have an inverter I use for my laptop while in the truck (and not driving! LOL). I plug the inverter into the outlet, going from 12v to 120v. When the power goes out, I plug the CPAP into the inverter. Done. No extra money going to Resmed for a 'special' adapter. I don't use the humidifier in that situation because any device that is designed to generate heat is going to drain a battery really fast.

I'm aware of the 12V/120V inverter method, but wanted to avoid the extra losses in the conversion process. Actually, the main thing I wanted to know is the actual output voltage under load of the larger ResMed power brick. I guess I'll just have to measure it myself.
Thanks for the reply.

[Sleepster]

Has any one tried to use a 12VDC to 120VAC 300W inverter using a modified wave form(squared sine wave) to power a System One CPAP machine

The native voltage for this machine is 12 V DC. Instead of inverting the electricity from the battery to 120 volts AC and then running it through the power brick that converts it back to 12 V DC you could just connect it directly to the battery.

You'd be best to go with the two cables provided for this purpose as they contain fuses and are recommended by the manufacturer.

Check out SKU 1001979 from Supplier #3 on our Apnea Board's Supplier List.

[archangle]

What is the actual output voltage (under load) of the power brick that is used with the ResMed S9 and H5i humidifier? It seems to me that I read somewhere that the voltage was 24V DC and elsewhere I read that it is 12V DC. Could a 24V or a 12V (as the case may be) storage battery be used directly as an emergency supply instead of having to go through the ResMed regulator adapter?

It's 24VDC. Look on the label for the power brick.

There's a third wire, though.

Consensus seems to be that the third wire tells the blower unit which power supply it's attached to, so it knows whether it can power the humidifier and/or heated hose.

Speculation is that it may be "interlocked" to keep you from using a non-ResMed power supply, but nobody's come up with any details.

[Bernie]

What is the actual output voltage (under load) of the power brick that is used with the ResMed S9 and H5i humidifier? It seems to me that I read somewhere that the voltage was 24V DC and elsewhere I read that it is 12V DC. Could a 24V or a 12V (as the case may be) storage battery be used directly as an emergency supply instead of having to go through the ResMed regulator adapter?

It's 24VDC. Look on the label for the power brick.

There's a third wire, though.

Consensus seems to be that the third wire tells the blower unit which power supply it's attached to, so it knows whether it can power the humidifier and/or heated hose.

Speculation is that it may be "interlocked" to keep you from using a non-ResMed power supply, but nobody's come up with any details.
[/quote]

Good information! I'll try to follow through and I'll let you know what I find out.

[SuperSleeper]

I simply purchased the S9 DC Converter....

Not cheap at around $85, but it's designed for the job by ResMed and it works, and no power loss through an inverter with worries about pure vs. modified sine wave.

Sometimes 'ya gotta bite the bullet and go with what works best.