My weekend from hell (or should I buy a UPS?)

Ha!


The 2000/2001 California power "crisis" (re:Enron flicking the switch on/off and rolling brown/black outs to bump up prices...) made me go out and buy UPS systems for home.


3 Cyberpower 1500 units. 2 for the computer/server room, and one for the HT room. These also have some power cleaning in them too - though not too high end.


I feel more secure that if the power goes out again (not happened in a long time while the HT has been running) my PJ won't be damaged ... hopefully.


- Rick

I AM LUCKY TO LIVE IN ARIZONA

NO POWER PROBLEMS


YOU HAVE FAR TO MUCH INVESTED

IN YOUR H.T. IN BOTH TIME AND MONEY

TO LEAVE IT TO THE TENDER MERCY'S

OF A UTILITY PROVEN UNRELIABLE





XANATOS

OH NO

WELL TO LATE NOW

I GUESS I HAVE CALLED

DOWN THE CURSE OF THE H.T. GODS ON MY HEAD


AND I HAVE A BIG OLD LIGHTNING MAGNET

IN MY BACK YARD A C BAND SATELLITE DISH

A VARY TEMPTING TARGET



XANATOS

F&*(@*&$( power company.


I'm still out.


Don't move to NY.



Gotta order a UPS I guess. I wouldn't go with anything below a big SmartUPS anyway, for exactly the reason nkopoian pointed out: they offer a pure sine-wave. A SmartUPS isn't ideal for your power amp, but its perfect for everything else in the equipment rack.

Quote:
Does anyone know how exactly these things do Sine-Wave reconstruction? Has anyone looked at the sine wave of these devices using a 'scope to really see how well they reconstruct the sine wave when they're feed an over/under-voltage?


Sort of hard to do actually as you'd need a worst case scenario to really see how well the reconstruction is done.


Reason I'm asking is because of the huge price differences between models available that do sine-wave reconstruction only:


APC has a couple of models ( LR1250 for 1250VA and LR600 for 600VA) which sell for dirt cheap at around $150 average. No batteries in these - they're purely for filtering and sine-wave reconstruction as long as your input's between 85-150VAC. Much cheaper then their actual UPS products.


Now on the 'audiophile' end, PS Audio has the PS600 (only 720W max) for $2400US and it also does complete sine wave but at x10 the price!


The PS600 is most likely better, but I'd have to buy two making the price $4800 instead of $375 for the APC's!


How *much* better is the question I suppose!


Kal

Actually, the PS Audio Power Plants are Power Generators and NOT a UPS. If the electricity goes down, they won't function.


A UPS uses a battery, so when the power goes down, it generates power using the battery.


OTOH, the PS Audio Power Plants are also AC Power Generators - it uses the electricity from your wall sockets to power its own system that in turns generates an AC power. The uniqueness of their devices is that the AC generated is very good - very close to a pure sine wave - with little/no disturbances/kicks/etc. etc. This results in the downstream components to produce better DC voltage to power their circuitry - resulting in lower noise floor, etc. etc.


UPS-es are just boxes that have battery and they don't do anything special in generating the AC out - on some cheaper models they even generate square wave instead of sine wave.


Whether the difference between the 2 sine waves generated by both products, and the resulting difference that comes with it on the downstream components are revealing enough and/or worth the extra $4500 difference is up to you to decide .

Originally posted by budiman
Actually, the PS Audio Power Plants are Power Generators and NOT a UPS. If the electricity goes down, they won't function.


A UPS uses a battery, so when the power goes down, it generates power using the battery.


Yes, exactly. I stated in my post above that I was only looking at comparing devices that do sine-wave reconstruction, not UPS's (I guess this is sort of off-topic to the thread then I suppose).

OTOH, the PS Audio Power Plants are also AC Power Generators - it uses the electricity from your wall sockets to power its own system that in turns generates an AC power. The uniqueness of their devices is that the AC generated is very good - very close to a pure sine wave - with little/no disturbances/kicks/etc. etc. This results in the downstream components to produce better DC voltage to power their circuitry - resulting in lower noise floor, etc. etc.


Exactly. I'm just wondering how the other APC sine-wave generators are different from the PS-Audio. APC's web site tells you NOTHING about how their sine-wave reconstruction actually works.


Ideally I'm just wondering if anyone's put a 'scope on the output of some of the more expensive (ie: PS-Audio) sine-wave regenerators vs. some of the cheap ones (APC) during a bad voltage lag or over-voltage condition. While the PS-Audio will most likely look cleaner, I'm just wondering what the cheaper models DO NOT do correctly.


Kal

Guys,


I work for APC


The output of the LR1250 is from an isolation transformer, it basically takes the power into a 1:1 transformer with surge protection. It has multiple taps that switch quickly to regulate the power going out to the load. That is how it maintains a constant voltage output.


AS for the UPSs, the less expensive (I am not allowed to call them cheap) units convert the DC of the batteries to a simulated AC called a step approximated wave. If you look at it on a scope, it looks like steps going up and down, both above and below the zero crossing line. This type of power is OK for computer power supplies and most electronics.


The pure sine wave units convert DC using transistors that pulse quickly, and by regulating how long they are turned on, you can control how they charge AC capacitors. The final output is exactly like the utility power you see coming into your home. That is why they are the UPS of choice.


Regards,


Nick

Originally posted by spearce:
Kal did my favorite pasttime here, take the thread off-topic. How dare he.


Sorry Tim! I couldn't resist!

I'm looking at either UPS or voltage regulators with some smarts, in that if the line goes below say 90V AC or over 130V AC that it trip off and just stay off, even if I'm not home, until I manually reset it. Clearly a UPS would provide "clean" power until battery failure. Some of the other devices out there that aren't a UPS might provide the behavior I'm after. Hmm


My thoughts exactly! (so maybe I'm not off-topic! Ha! ). The products that provide UPS in addition sine-wave correction seem to be a LOT more expensive the the units that only do sine-wave correction. All models seem to do some sort of filtering that should [in theory] block any transients sent by the power company when power returns to normal. Running an entire HT on even the biggest UPS would probably only give you 5 minutes of power anyway - what's the point? If you had an bulb projector I could see putting that thing on a UPS to ensure that it cools off properly if ever there's an outtage as the bulb can shatter if you just unplug the unit all of a sudden.



Originally posted by nkopoian
Guys, I work for APC


This forum is simply amazing! Thanks for posting Nick!

The output of the LR1250 is from an isolation transformer, it basically takes the power into a 1:1 transformer with surge protection. It has multiple taps that switch quickly to regulate the power going out to the load. That is how it maintains a constant voltage output.


Interesting! I guess the +/- 5% swing on the 117VAC output (manual states the output is anywhere from 111VAC to 123VAC) is because there's a limited number of taps...... you'd have to add x5 as many if you wanted only a +/- 1% error. This would also cause more switching which is not a good thing either.

AS for the UPSs, the less expensive (I am not allowed to call them cheap) units convert the DC of the batteries to a simulated AC called a step approximated wave. If you look at it on a scope, it looks like steps going up and down, both above and below the zero crossing line. This type of power is OK for computer power supplies and most electronics.


Yep - this is what I wanted to make sure I wasn't getting into - these are ok for most electronics that use switched mode power supplies, but it's not the best idea for most audio equipment.

The pure sine wave units convert DC using transistors that pulse quickly, and by regulating how long they are turned on, you can control how they charge AC capacitors. The final output is exactly like the utility power you see coming into your home. That is why they are the UPS of choice.


This sounds like the best of the 3 it seems. Is this true?


So simply put, what APC product would *you* choose if all you cared about was power line filtering and AV sine-wave recontruction to fix sags and overvoltages? If the last option's the best it looks like we may need to buy the product with a UPS built in even though it looks like we may not really benefit from the UPS feature...


Thanks!


Kal

i have done my fair share at cursing the power company , here in the okanagan we have a utilty that sounds alot like what spearce is experiencing in new york, these clowns here have already burnt one 50 inch t.v. (790$ repair) semi-toatsed one fridge (1000$) to replace , use the old one for a beer fridge, and when i ask these idiots what the probelm is with all of the power outages they say that since the power company was sold to the u.s. its not their responsebility, so to protect from future power surges i had to resort to installing surge protecters on everything, computer, crt projecter , all appliances, etc. so spearce you aren,t alone....there should be a class action lawsuit brewing someplace for all the people that had all their electronics destroyed by" reliable" power suppliers...........