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Discussion Starter · #1 ·
Ok, at the end of this first attempt at HTPC'ing and HT building, I'm going to have an investment of some $3000 sitting within 4 foot of an electrical outlet the I fear can be the disbursor of death should I get a spike.


Sags are less worrisome, but they bother me as well. Finally, I want CLEAN and CLEAR power for my stuff.


What can I use aside from a Rack Mount UPS (which is ugly as all get out).


And don't UPS's have issues with square waves vs. sine waves? Isn't electronic equipment (amplifiers I'm thinking here) pretty picky about what it eats?


I just don't want to plug it into the wall and go. That's stupid.
 

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UPS's do have digital output of power rather than analog. This can be described as squares rather than curves. This is the best option if you want clean power.


APC's is anopther option to look at. It also has its own disadvantages, but I would reccomend it over a UPS.


If you are concerned about it looks, remember it can be quite a ways away from the server you are powering. Which enables you to hide it somehow.
 

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The APC Smart UPS generate sine waves. Definitely go UPS for the PC. I also have a UPS for my projector. Rest of the equipment is off a line conditioner. The black rack mount apc units look nice...
 

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Quote:
Originally posted by chrontek
UPS's do have digital output of power rather than analog. This can be described as squares rather than curves. This is the best option if you want clean power.


APC's is anopther option to look at. It also has its own disadvantages, but I would reccomend it over a UPS.


If you are concerned about it looks, remember it can be quite a ways away from the server you are powering. Which enables you to hide it somehow.
Square waves? I've never seen or heard this before, are you sure? I would think that non-standard AC power would be potentially damaging to electronic equipment.


Ozy
 

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The cheap ups's generate square waves.
 

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Quote:
Originally posted by mjcumming
The cheap ups's generate square waves.
Thanks for the info, learn something new everyday. Turns out my APC UPS uses a stepped approximation (according to product literature). Perhaps I should borrow an O-scope from work and see just what I'm getting on battery.


Thanks again,

Ozy
 

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Discussion Starter · #7 ·
Spoke too soon! Found this excellent information on google groups Here .
 

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All my stuff (RPTV, HTPC, cablebox, VCR, receiver) is on an APC SmartUPS 1500. Takes care of brownouts, overvoltage, spikes/surges and is of course un-interruptable. Hi-def TV looks great (as does DVD), receiver sounds great. Works for me.


This UPS produces a sine wave. I'd not dismiss the cheaper ones that produce a stepped-sine wave either though: The only time that's an issue is when the power goes out and you're running on battery. So what if your receiver doesn't sound right when that happens. Do you really need to be listening to CDs while the power is out? It at least lets you shut things down properly and provides surge protection 100% of the time.


-Rob-
 

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There was a lengthy discussion of square vs sine waves in the projector forum a year or so ago. The purists felt the square waves would damage you projectors power supply - who knows? But for a modest increase in price I decided it was a mute point - get a ups that makes sine waves :)
 

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Quote:
Originally posted by Ozy666
Square waves? I've never seen or heard this before, are you sure? I would think that non-standard AC power would be potentially damaging to electronic equipment.


Ozy
Ozy,


Computers have "switching" power supplies that are not bothered by square waves - they essentially "chop up" the

wave anyway.


Because it is cheaper to make an inverter that outputs a square wave, which computers don't mind - the least

expensive UPS units intended for computers will output square waves when on battery.


However, the better units - like the APC Smart UPS series have inverters that output sine waves - like what comes

out of a wall socket. If you intend to power a non-computer component that may not have a switching

power supply - use a UPS that outputs sine waves like the APC SmartUPS.
 

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Discussion Starter · #11 ·
Don't all (switching or not) power supplies inherently by their very design contain circuitry and components that in effect level, stabilize and clean up the power somewhat before rectifying and inverting it over to DC?


I guess in my quest to make sure I have the 'spring water' of AC coming into my components, I really need to think about what the possibilities are which the components may run into. Plus the fact that consumer electronics are engineered with some degree of 'idiot factor' -- being that the electronics themselves are designed to operate within a range of potential household situations.


Some things that concern me are:


Lightning - anything but a sophisticated lightning aversion system will not suffice, but I can try to put my faith in a quick acting Panamax, for instance. I'm not sure of a UPS's ability to fuse out in time.


Surges - [being a temporary (up to 5 second) overvoltage condition] -- should be handled by the power supply circuitry and transformer and dissapated as heat.


Sags - [being the opposite of a surge] would be minutely taken care of by the capacitors in the power supply circuitry. But I'm not quite sure of how long and how deep of an undervoltage condition can be handled. Probably sub 1 second. I worry then about inductive kicks throughout my houses power grid and the fact that a sag could last for 3-4 seconds as a vacuum or TV draws it's first electron breath.


Spikes/transients - more of am EMI/noise issue, probably occur much more frequently than I'd like to admit -- but should be handled by the power supply circuitry (diodes, windings, caps, inductors).


Brownouts/Blackouts - no need to address this, but the potential would be nice to be able to gracefully shut down my amps and projector (Sony W400Q's need to run for several minutes after lamp off to continue cooling).


I guess my main issue is : what is enough, and what isn't.


I understand that putting a quality UPS inline with my equipment will probably meet all of the requirements above (sag/spike/transient/surge).


I just wonder if it's overkill and if a Panamax and/or good quality spike protector won't suffice.



Thanks all...
 

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I went Smart UPS so that I had enough run time to cool my projector. Look at the APC specs. I don't believe you need a line condition as well. It does this.
 

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I vaguely recall that there was a place that sells refurb Smart UPS (w/ new batteries) at great prices? Is there anybody around who could post a link?


Thanks!

_____

Axel
 

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I have an AE100 projector from the same batch that supposedly used bad power supply components. Since I bought it used on eBay (only 30 hours on it) and it came straight from Japan, I figured I'd have a hard time getting it repaired under warranty. It was at this time (~1.5 years ago) that out of fear, I purchased an APC Smart UPS on eBay [from PEII, they sell refurbished, (read this as "brand-new batteries" at cheap prices) APC units mainly to large companies]. After all this time (3227hours) my projector's power supply has never had a problem! This UPS supplies a sine-wave and so I also plugged in all my stereo equipment including a powered sub, antenna amp and 2 rotator controllers, a replaytv, DishNet sat receiver, wireless headphones, IR transmitting and relay units, several theater lamps and lights and fans... and finally my computer. The computer was the only thing I've had problems with. Whenever we turn on the dryer or washing machine or the furnance or air conditioner, its usually a 50/50 chance that the computer will reboot. After a year of this I finally had had enough one day and went right out and purchased a CyberPower UPS (squarewave) and used this exclusively for the computer... its been over 3 months now and no more reboots! The conclusion I've drawn from this is that computers prefer squarewaves I guess.
 

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I run my DirecTivo and HTPC off a UPS. Everything else is directly wired to the walls. If a large spike occurs then I will use my insurance policy.
 

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Quote:
Originally posted by jcarlsony2k
Don't all (switching or not) power supplies inherently by their very design contain circuitry and components that in effect level, stabilize and clean up the power somewhat before rectifying and inverting it over to DC?
jcarlsony2k,


Yes - but what else is the component doing with the incoming power.


For example, take your TV set. The standard NTSC signal for a TV - is 480i @ 60 Hz - the refresh rate on a regular

old TV is 60 Hz.


Where do you think the TV gets its "clock" signal from?


That's right - it keys off the 60 Hz power line signal.


Lots of electronics do that - they are dependent on the sine wave oscillation of the input power to provide a timing

reference.
 

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Quote:
Originally posted by jcarlsony2k



Some things that concern me are:


Lightning - anything but a sophisticated lightning aversion system will not suffice, but I can try to put my faith in a quick acting Panamax, for instance. I'm not sure of a UPS's ability to fuse out in time.
If you are concerned about a lightning strike hitting a power line and discharging into - that's a lost case.

A lightning discharge that has the voltage to leap hundreds if not thousands of feet through the air,

can't be stopped by anything in a Panamax.

Quote:


Surges - [being a temporary (up to 5 second) overvoltage condition] -- should be handled by the power supply circuitry and transformer and dissapated as heat.
UPS units will handle those just as well as regular surge suppressors.

Quote:


Sags - [being the opposite of a surge] would be minutely taken care of by the capacitors in the power supply circuitry. But I'm not quite sure of how long and how deep of an undervoltage condition can be handled. Probably sub 1 second. I worry then about inductive kicks throughout my houses power grid and the fact that a sag could last for 3-4 seconds as a vacuum or TV draws it's first electron breath.
Many UPS units will handle sags - even without drawing on the battery. They use "ferroresonant"

transformers. They don't store the energy in capacitors - but in the magnetic field of a big inductor - a transformer.


In fact, the ferroresonant transformer takes care of both sags and surges - by either drawing from or adding to

the magnetic field in the transformer.

Quote:


Spikes/transients - more of am EMI/noise issue, probably occur much more frequently than I'd like to admit -- but should be handled by the power supply circuitry (diodes, windings, caps, inductors).
UPS units will handle these as well. The idea of a UPS is to provide clean steady power. The cleanup circuitry

is less costly than the standby power function - so the cleanup circuitry is usually included.

Quote:


Brownouts/Blackouts - no need to address this, but the potential would be nice to be able to gracefully shut down my amps and projector (Sony W400Q's need to run for several minutes after lamp off to continue cooling).
Yes - that's why many people go with UPS units. They can allow you to shutdown the HTPC computer, and

run the projector through its cooldown cycle, and, in general, allow a graceful shutdown of the HT system.

Quote:


I guess my main issue is : what is enough, and what isn't.


I understand that putting a quality UPS inline with my equipment will probably meet all of the requirements above (sag/spike/transient/surge).


I just wonder if it's overkill and if a Panamax and/or good quality spike protector won't suffice.

.
A good UPS will do everything the Panamax does PLUS allow the graceful shutdown and cooling of the

components in the event of a blackout.
 
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