A/C vs. D/C

Most CPAPs sold nowadays run on DC. The wall current is AC from 100 to 240 volts and 50 or 60 hz (depending on which country you're in). Therefore, the CPAP machine uses a transformer (or brick).

Apparently, Fisher & Paykel CPAP machines are the exception; they run on alternating current. They do seem to be compatible with the voltages and frequencies used throughout the world.

If you want to go camping or have a backup battery, this is possibly a disadvantage.

This having been said, I used this brand of CPAP from 1999 until 2009 with great success and no compatibility issues (despite frequent international travel).

As are most XPAPS made today, Mr. Obvious, very informative. Jim

Goofproof wrote: ↑

Tue Feb 26, 2019 10:24 am

As are most XPAPS made today, Mr. Obvious, very informative. Jim

My point was that F&P CPAPs run on alternating current, which might have certain advantages and certain disadvantages. Not having an external power brick might be an advantage to some. Not being able to use a battery without an inverter might be a disadvantage.

I didn't see you having a point. The point is almost all XPAPS used now, use both, some use Power Bricks, some have the same type of parts built inside of them. Smart manufacturers, include options for both power options. That's the point I see. Jim

In the end it all comes down to the hamster running inside a wheel to turn a generator. Give the hamster, food and water, hope he wants to run.

They ALL run on AC, which they convert to DC. For most electronics. the converter is the "soap on a rope". For others it is internal, making the machine heavier. Decades ago I had a Toshiba laptop that had the power supply built in and I liked having no "brick". But the computer was heavier, and warmer!

Apparently, F&P CPAPs have true A/C motors (no conversion to D/C). Somehow, they'll work with 110 or 200 volts and with 50 or 60 cycles.

D.H. wrote: ↑

Mon Mar 04, 2019 6:17 pm

Apparently, F&P CPAPs have true A/C motors (no conversion to D/C). Somehow, they'll work with 110 or 200 volts and with 50 or 60 cycles.

bullcrap. If they were "true A/C motors (no conversion to D/C)" they wouldn't be able to vary the speed to achieve different pressures.

Stop talking about stuff you have no clue about.

Resmeds have AC motors... 3 phase AC motors, or "brushless DC motors" in the parlance of drone people... but 'brushless DC" motors are actually 3 phase induction motors.

Respironics probably do to, in fact, I'm sure they ALL do, otherwise they couldn't produce accurate speed control to keep the pressures exact.

palerider wrote: ↑

Mon Mar 04, 2019 7:38 pm

D.H. wrote: ↑

Mon Mar 04, 2019 6:17 pm

Apparently, F&P CPAPs have true A/C motors (no conversion to D/C). Somehow, they'll work with 110 or 200 volts and with 50 or 60 cycles.

bullcrap. If they were "true A/C motors (no conversion to D/C)" they wouldn't be able to vary the speed to achieve different pressures.

Stop talking about stuff you have no clue about.

Resmeds have AC motors... 3 phase AC motors, or "brushless DC motors" in the parlance of drone people... but 'brushless DC" motors are actually 3 phase induction motors.

Respironics probably do to, in fact, I'm sure they ALL do, otherwise they couldn't produce accurate speed control to keep the pressures exact.

I can't help but believe we are going to get a very specific definition of what "true" means. That is, if D.H. were a true Scotsman.

Dog Slobber wrote: ↑

Tue Mar 05, 2019 11:10 am

palerider wrote: ↑

Mon Mar 04, 2019 7:38 pm

D.H. wrote: ↑

Mon Mar 04, 2019 6:17 pm

Apparently, F&P CPAPs have true A/C motors (no conversion to D/C). Somehow, they'll work with 110 or 200 volts and with 50 or 60 cycles.

bullcrap. If they were "true A/C motors (no conversion to D/C)" they wouldn't be able to vary the speed to achieve different pressures.

Stop talking about stuff you have no clue about.

Resmeds have AC motors... 3 phase AC motors, or "brushless DC motors" in the parlance of drone people... but 'brushless DC" motors are actually 3 phase induction motors.

Respironics probably do to, in fact, I'm sure they ALL do, otherwise they couldn't produce accurate speed control to keep the pressures exact.

I can't help but believe we are going to get a very specific definition of what "true" means. That is, if D.H. were a true Scotsman.

Very specific, and irrelevant, if past postings are any indication.