Hey guys,
I would just like to ask if the new IMac 21.5 in. (late 2012) is compatible to run with a UPS (uninterruptible power supply) that emits a modified sine wave output when on battery?
Thanks in advance!
iMac, Mac OS X (10.7.5)
Hi Shootist, thanks for your insights!
I am very truly sorry for insulting your genius but, in answering my question with another question, are you saying that a UPS emitting modified sine wave when on battery will work with the new IMac because it works with other PCs? I am not disputing that parts of an IMac are different with those in other PCs, but I am afraid that you're response is a little deficient with all due respect .
Well, if you must know, some PCs and some earlier Macs are precisely having trouble running on a modified sine wave UPS. Such troubles consist in the computer's PSU making noise, the computer constantly restarting, or even the computer shutting down completely when on UPS battery. I say some because it seems to affect some but not all Macs or PCs. There are opinions floating around the internet that such troubles may be caused by the incompatibility between the modified sine wave UPS and a computer whose PSU has an active PFC. On the other hand, there are those that express opinions that the incompatibility of the modified sine wave UPS is not with all PSUs with active PFCs but only with certain brands of PSUs. But then again, they are just opinions and are far from being definitive.
So you see Shootist, I think you can forgive me for just asking a specific question in relation to the new IMac. I just want to know, preferably from those who own the new IMac and has it plugged into a modified sine wave UPS, whether that set-up poses none of the troubles I identified above.
Hence, I ask again: Is the new IMac compatible to run with a UPS that emits modified sine wave output when on battery?
What would make you think an Apple computer that uses the same exact parts as any other computer on the market today, Intel Inside like most all Windows computer, would not work with a Good name brand UPS.
What do you think is going to happen to the Mac, that wouldn't happen to a Windows PC, with this modified sine wave output?
In all honesty if you are using your Mac and the power goes out and the battery backup takes over it is time to Save your work and Shut the system down.
UPS's are for that reason. Not to continue working on the computer for any extended period of time. They are so you CAN save what you are working on and do a proper shut down so drives/files/OSs do not get corrupted. If you need to work on battery only then you should buy a notebook as they are designed to run on Battery Power only.
Well hopefully you can tell by the number of other responses that your concern isn't found by other users of this forum.
If it is such a concern then buy a Pure Sine Wave type.
All hardware in all consumer type computers made today are basically the same. They all use Intel CPUs and chipsets and either ATI/AMD or Nvidia graphic. Sure some parts may be slightly different but in the end they all must do the same thing.
I know this is a very very old thread, but I just wanted to point out that Shootist007 is completely incorrect. It's fairly obvious he knows nothing of active power factor correction, something that's been around for decades in industrial electrical equipment and is just now making it's way to high-end computers.
To answer your question: No, a modified sine wave inverter will not work with an iMac reliably, because the power supply DOES use active PFC which looks for the pure sine peaks and measures RMS. Some of the newer iMacs will just shut off if you feed them MSW instead of pure, because the active PFC can't correct the waveform enough.
At least Shootist007 did manage to get one small point almost correct: newer PCs are using active PFC now too, so most likely any MSW inverter is only going to work on older equipment (both PC and Mac).
Thanks for answering my question Rob328!
About two years ago, or some years before that even, the concern about the possible incompatibility between PSUs with active PFCs and modified sine waves were not yet definitive, much less widely known. It was good to hear the educated input of someone who knows what I am talking about and settle the issue for me, at least from a theoretical standpoint. It may be two years too late, but I sure heck appreciate it!
Again, thanks!
P.S. I actually held off from buying a modified sine wave UPS for my iMac. 😉
Modified Sine Wave UPS for IMac 21.5 in. (late 2012)
