JayDee wrote: ↑Thu Sep 17, 2020 5:41 am
Whatever/whenever ResMed announces the next model, I'm hoping they dump that proprietary power supply and just stick to plain ol' boring 12 volts.
-JD
There's a good reason to use 24v. Quick electricity lesson that you may or may not know. Wire size (diameter) depends on the current draw of a device. Higher current needs thicker wires. The device itself uses power, which is voltage times current and is measured in watts. Let's say the device uses 80 watts (my current cpap and my prior cpap both have 80 watt supplies). The resmed device at 24v draws a maximum of 3.3 amps. The respironics device at 12v draws a maximum of 6.6 amps.
So resmed could use a more flexible wire cable and avoid the cable overheating. The power input jack is less likely to overheat. (I've repaired many a laptop computer with that problem).
Both companies require you to use a dc power cable. The respironics cable merely has filtering, the resmed has a voltage converter as well. They can both be powered on 12v.
The downside is that the voltage converter can't be 100% efficient. I don't know the efficiency of this converter. 90% is a good approximation. That does mean that for the same power needs the resmed device will need about 10% more battery capacity.
So like everything there are tradeoffs. I'm not defending one choice over another but I'm saying it isn't as arbitrary as it may seem.
Sleep loss is a terrible thing. People get grumpy, short-tempered, etc. That happens here even among the generally friendly. Try not to take it personally.