Date: Thu, 27 Nov 2014 13:22:49 -0800 From: Darren Pilgrim <list_freebsd@bluerosetech.com> To: nightrecon@hotmail.com, freebsd-questions@freebsd.org Subject: Re: UPS for FreeBSD Message-ID: <54779629.302@bluerosetech.com> In-Reply-To: <m581p1$65m$1@ger.gmane.org> References: <CAHieY7QGp2ELF-R91eu=vSrPsimVmVNJQ4kfucQ56PR7EEZmig@mail.gmail.com> <m57qdq$did$1@ger.gmane.org> <54777AB1.9010800@bluerosetech.com> <m581p1$65m$1@ger.gmane.org>
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On 11/27/2014 12:32 PM, Michael Powell wrote: > Darren Pilgrim wrote: > > [snip] >>>> Or any other off-the-shelf inexpensive UPS that I can buy at Staples or >>>> Best Buy that will work with FreeBSD via USB to shut down the server >>>> gracefully. >>> >>> Been looking at the CyberPower ones myself lately. If this is for a >>> desktop type box with an active PFC power supply go pure sine-wave. The >>> higher the efficiency rating of the power supply the more touchy they are >>> wrt the non >>> pure sine wave variety. Almost all modern desktop power supplies today >>> are active PFC, so the pure sine-wave is becoming a 'must-have'. >> >> Sine-wave approximating inverters do bad things to any power supply with >> a regulator cap (which is everything that won't catch fire on its own). >> The issue is the high frequency components and the hundreds of under- >> and over-voltage events per second inherent to the stepped square >> waveforms used (every step is a spike or sag). >> >> UPS manufactures know this is bad, so they try to hide it by calling it >> "modified sine wave", "quasi sine wave", "simulated sine wave", "PWM >> sinewave", etc., and hope you're dumb enough to fall for it. I have yet >> to see a consumer UPS that doesn't do this. >> >> You need to buy a server-grade UPS to get something that won't damage >> your electronics. APC SmartUPS, Cyberpower PFC Sinewave or Smart App, >> Eaton 5P/PX or 9 series, Tripp Lite SmartOnline, etc. > > I absolutely agree. I have a large line conditioner I pulled from a mini- > frame that was being decommissioned and scrapped. It filters line noise, > spikes, transients, high-freq noise, etc, and contains a constant voltage > transformer that can even buck up short line voltage sags. There is no such > advantage to having/using such a beast only to place a non pure-sine wave > UPS between it and the computers. Defeats the purpose of having it in the > first place as such units will only reintroduce all the crap the line > conditioner cleans up. > > Of course, the obvious idea would be to put the UPS in front of the line > conditioner, but that's also a no-go for various other reasons. > > Was just bringing this up to say: spend the extra money and get something > good. My main background early in life was analog electronics and RF, before > I got into computers. I've been looking around for something inexpensive for > home use, but my show-stopper spec is I won't use anything that isn't pure > sine wave. And that translates to $$$. Haven't found anything yet that is > inexpensive and satisfies my requirements. A 750VA or 1000VA SmartUPS can be had for around $250, and every now and the big box stores and Walmart carry them for around $300. Not too bad considering what you get.
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