TheMGPremium
join:2007-09-04
Canada
kudos:1 | reply to whizkid3
Re: "pure sine" in UPS said by whizkid3:Yeah - with a crappy little UPS I can see that it could be possible.
Yeah when referring to a "stepped wave" I was referring to the kind of crap you get from a cheap UPS:
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Reviews:
 ·AT&T U-Verse
| Re: "pure sine" in UPS said by TheMG:Yeah when referring to a "stepped wave" I was referring to the kind of crap you get from a cheap UPS:
Is that with no/very small load by any chance?
Anyway most electronic devices wouldn't care too much...
Makes me curious to look at what my 6yo $40 re-branded APC outputs... will post tonight if I don't forget... |
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TheMGPremium
join:2007-09-04
Canada
kudos:1 | said by cowboyro:Is that with no/very small load by any chance?
Anyway most electronic devices wouldn't care too much...
Makes me curious to look at what my 6yo $40 re-branded APC outputs... will post tonight if I don't forget...
I have found the waveform to change very little with these types of UPS, regardless of output loading. Only thing that changes is you might get a bit of ringing with some loads.
Your $40 UPS most likely uses this exact waveform.
Cost is the only reason they do it. It requires less components and is highly scalable with little modification. |
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Reviews:
·AT&T U-Verse
| said by TheMG:Your $40 UPS most likely uses this exact waveform.
Cost is the only reason they do it. It requires less components and is highly scalable with little modification.
And you are right... same waveform, no change with a 40W resistive load.
Funny thing is it would be fairly cheap to make a somewhat sine wave with very, very little extra cost... but then it's most likely a marketing perspective when you can ask for $300 more although you spend $3 extra in parts... |
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| reply to TheMG
Re: "pure sine" in UPS
STEPPED - UPS output |
Seemed to run my computer fine with this output though I do recall that if it was powering a CRT monitor you would get this funny thin bright line that would float up the screen every few seconds. I still have both UPS' and aside from battery replacements they still work well, though I prefer the additional features of the newer models.
One thing I don't like about the older BACK-UPS is that the UPS will leak some current back out on the neutral wire during a power outage. APC had a little note about that buried in their site, but I found out via the more traditional way of being shocked by the damn thing.  |
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| Someone needs to check the compensation on the 10x probe...  |
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| Re: "pure sine" in UPS Indeed, seems just a tad off. 
If I can unbury my workbench I will have to repeat the test again. |
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