UPS for FreeBSD

[Darren Pilgrim]

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.