Why Haven't UPSes Been Integrated w/ PC Power Supplies?

antiher0 asks: "A while back, while connecting the batteries to 20 UPS's at work, I had a revelation. Well... maybe it wasn't that subtantial, but I thought of something that noone I talked to could answer. UPS's work by storing energy in a standard battery (undergoing a transformation from AC to DC in the process). When the power goes out or a brownout occurs the energy stored in the battery gets converted into AC and is sent down the power cable to the end device where may be converted back to DC again (as in the case of a standard PC). These conversions between AC and DC are not very efficient. Why not just have a system that places the battery and logic board within the power supply of the PC? (or at least hooks up to the power supply, the battery need not physically reside in the power supply) By doing this, you streamline the whole process and make the whole thing a bit more convenient. There are, of course, more issues to deal with, but I think it'd be feasable." This is a good point. If PC power supplies were external, they could be integrated with the battery/UPS and maybe we could save a bit of energy by performing one less AC-to-DC conversion which could potentially save some wear on the battery. Is there any reason why something like this couldn't work?

Comments

It's all about the Benjamins

[green pizza]

Aside from PC Power & Cooling, the PC power supply tends to be 'cheaper, cheaper, cheaper'. Adding anything more than what a basic ATX power supply needs to operate will just drive up costs and help only a small percentage of users whilst everyone else complains. That, and it won't exactly be cheap or easy to design... greater complexity, more regulatory aprovals needed, more parts to fail, etc.

I would imagine that if such a combo UPS/power supply were to be introduced, most folks and reviews would still prefer to purchase and use their own favorite standard models. Folks like a choice, even if it means taking more wattage from the wall. Just look at modern x86 CPUs. Someone could make a modern all-in-one workstation based around a newer rev of the Crusoe or StrongArm and some cots chips to accelerate video, etc. Have the chip makers and your own design teams understand the need for power conservation. Could easily end up with a highly efficent, cool-running, and still powerful workstation if it was a well-designed and well-managed joint effort. But... there is no way it would be cheaper than building your own PC piecemeal and just getting a beefy power supply.
More (electrically) efficent hardware would be nice. Powerful hardware is always nice. All-in-one is neat. Choice is good too. A cheap price would be perfect.... but they just don't go together too well, plain and simple.

Re:It's all about the Benjamins

[adolf]

As long as we're mentioning PC Power & Cooling, some years ago these people produced a tower-sized power supply with built-in batteries. It's a slightly large beast, and likely wouldn't fit into most of today's cases at all. It also provides no means of status updates, so a graceful shutdown during a blackout would be rather difficult.

But, the thing works. We've got one in an ancient full tower AT case at work, which had its batteries replaced a few years ago. No trouble to report about it.

If anyone wants one, scout the hamfest/flea market circuit or Ebay. If memory serves, the only external clues that it is a UPS are that it is painted black, and a good deal heavier than other similar supplies.

Laptops have this :-)

[kilrogg]

Laptops already do this, and do it quite well. The efficiency of eliminating the DC-AC-DC conversion allows my laptop's "UPS" to last between 2-3 hours when a blackout occurs (well the power saving features of the laptop helps too).

I guess one of the problems with desktops is that the monitors still require AC power, so it'd be useless to have a battery integrated in to the box if it didn't have a DC-AC converter to supply power for the monitor. Then the power wasted to power the Monitor would probably make the savings from skipping the DC-AC-DC conversion for the computer not very worth while.

If you had a DC powered LCD screen, on the other hand, then it would probably make sense.

Already Exist....

[fwc]

You can buy these from various suppliers. Instead of pointing you towards any particular one, I'd just start with the results of this google search.

It appears there are three main types. Those which replace the existing atx supply, those which Plug into an PCI Slot and those which fit into a drive bay.

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Should UPSes be tossed?

[JabberWokky]

I've heard from many people that UPSes (or at least your typical "loaf of bread" under the desk type UPS), should be disposed of after suffering a power spike.

Now, I know that this applies to surge devices in power strips - I've opened them up and seen the fused breaker. I'd imagine that YMMV depending on the brand of UPS (I have APCs on all the equipement around the house, and a big honking APC under the main rack in my home office (my colo NOC has two massive IBM things each the size of my truck)), but I've always wondered how much damage the cheap, common UPSes (and computer case power supplies, for that matter) can take before they should be replaced.

And yes, I am posting at 5:47am, late at night, not at 5:47 in the morning. Can you tell?

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Evan

Re:Should UPSes be tossed?

[autocracy]

Simple answer: If it's APC, no - Don't chuck it.

REAL /.ers only have a karma of 49...

Re:Should UPSes be tossed?

[adolf]

Except for a few special breeds (think ferroresonant transformers, motor-generators, or other solutions involving huge chunks of iron), all surge protection (including the much-touted APC stuff) consists of inexpensive varistors.
They operate by shunting to ground when voltage potential rises above a certain point (usually ~250VAC), which hopefully absorbes the spike until a circuit breaker or fuse pops, and hopefully even after that, should there be sufficient potential to arc across the fuse/breaker.

After a number of cycles of this, they eventually fail.

All of them.

And there is no method (at least, none that I've seen) which can accurately determine when they're no longer capable of conducting, short of physical examination (hint: if it's blown into bits, it doesn't work) or destructive tests (ie, hit it with 300VAC and see what happens).

That said, they're cheap. They're readily available (Mouser Electronics or Digikey). They're easily replaced if you're handy with a soldering iron. And, while periodic replacement of them will preserve the surge protection capability of the unit, it will also void any warranty or insurance you might have had before with your potentially-broken device.

(And, no, those little LEDs marked "Protected" on your surge protector are not functional. It's just a resistor and an LED across the power line, so it's absolutely nothing more than a power light. By design.)

No magic, here.

-48VDC

[cnvogel]

On telco-equipment the standard input is -48V DC. You can get routers/switches and PC power supplies with this input, too.

In case of a blackout they simply run on 4 lead-acid batteries.

This may be very convenient when powering your computer from solar cells, but unfortunately these -48V supplies tend to be very expensive :-(.

Re:-48VDC

[Nos.]

Yup, that's exactly what the telco's use. I was lucky enough to get a tour of Bell's main office in Ottawa (Canada). The batteries are a little larger than you'd find in your average car, but that's exactly what they are. All connected up to the power coming into the building, and all the equipment is then hooked up to these batteries.

We actually have PBX here where I work, and its the same thing, about 6 batteries inbetween the building power and the PBX.

As a point of interest, if anyone remembers the big "telephony blackout" awhile back around Toronto, where even 911 calls were down, the folks at Bell in Ottawa explained what happened. Apparently someone was changing batteries, or working near them, and a wrench fell onto the batteries and happenend to connect the + and - connectors (which are bare metal). As a result, a lot of equipment fried. Guess their surge suppression wasn't quite up to snuff!

Re:-48VDC

[Chris Hiner]

Here's the answer I found in the telecom digest FAQ:
Q: Why use a negative charge (-48 volts) for Ring instead of a positive charge (such as +48 volts)?

A: The reason for doing this is galvanic corrosion protection. A conductor with a negative charge will repel chlorine ions, as Cl (chlorine) ions are negative also. If the line were to have a positive charge, Cl ions would be attracted.

This form of corrosion protection is called cathodic protection. It is often used for pipelines, bridges, etc. Such protection was very important in the days of open wire transmission lines.

From:
http://mirror.lcs.mit.edu/telecom-archives/archi ve s/new-readers/frequent-ask-questions-97
(Take out the spaces)

Redundancy

[SanLouBlues]

Because, I want to be able to replace a fubar power supply without paying for a new UPS. And if I upgrade to a new power standard (P4) I don't wnat to pay for a new UPS.
What's that you say? Integrate them but make the powersupply and battery components seperate? What's the point? It's easier to manufacture powers supplies for every consumer from one or two basic designs (desktops/laptops). KISS

Re:Redundancy

[Valdrax]

What's the point? It's easier to manufacture powers supplies for every consumer from one or two basic designs (desktops/laptops). KISS

I suppose you dislike DVD-ROM/CD-RW combos and embedded CPUs with builtin bus and network controllers too. Some consumers have a use for these things even though you feel that most do not.

Many times there are overwhelming reasons why you want to combine components. I think his reasons are quite good. After all, there is a significant waste of power in going from AC to DC, from DC to AC, and then back from AC to DC as you go from wall to UPS battery to power supply to computer components. There's no reason to shoot down the idea for everybody else. Sometimes simple designs are inadequate.

I think the only reason these haven't taken off is that many people haven't thought of it, and most OEMs wouldn't use them because they would jack up prices. If they became better known, I'm sure that the market for them (especially in the business world) would take off.

The answer to "why"

[Paul Carver]

To paraphrase Robert Heinlein, whenever someone asks "Why don't they . . ." the answer is always "Money".

The PC market is extremely cost competitive. The power supply is one of the least important components to most computer buyers.

Also, most computer users in general would turn all electronic equipment off in a storm. If you're on a reliable power grid, a storm is about the only time you might lose power. I can only think of two or three times in the last decade when I lost power when there wasn't a storm.

An added cost part that many people will never see the use of is a very hard sell in such a cost competitive product.

Such a beast exist.

[Lord_Hern]

AMSDELL sells the IPPS commander, a 200 watt UPS power supply that fits a standard ATX form factor. I have used one very happily for 2+ years now. w/o the monitor plugged in I get about 18 minutes runtime and with my 17 inch monitor drawing I get about 9 minutes runtime. YMWV Don't know about other form factors or other power ratings. Lord_Hern

That's not redundancy...

[Spamalamadingdong]

... that's multiple single points of failure and additional pieces of hardware.

The UPS is such a big chunk of hardware because it tries to output 110 volts 60 Hz. Putting it in the PC's switcher eliminates all those frequency and voltage constraints, and makes it vastly smaller, lighter and cheaper. Plus, you have other markets open up:

• People who want to put a computer in an RV, and don't want to run an inverter all the time they're away from mains power.
• People who use solar or wind power, ditto.

Your point about the power supply market having big economies of scale is a good one, but the number of consumers in California, New York and other areas which have a > 50% likelihood of being hit by blackouts in the near future makes a pretty good market by itself, and enough volume to justify a power supply aimed at their needs. If you could get it into Dell as one of their options, they'd sell like hotcakes.
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spam spam spam spam spam spam
No one expects the Spammish Repetition!

UPS integration

[dwoolridge]

Dan Berstein asks a similar question and finds one or two answers. It seems like the only (readily found) solutions are American Advanced Power and Amsdell.

What about long power outages?

[Kris_J]

I've just started work at a place with one site that frequently has extended power outages. Giving everyone expensive laptops is not really in the budget. Desktops don't have to small and light, so I wonder if anyone has built a low power desktop PC with a battery that lasts a couple of hours, and is, say 30%, cheaper than a portable of equal specifications.

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Re:What about long power outages?

[nick_davison]

The kicker in your question is that lasts a copule of hours.

PCs are built safe in the knowledge that they're connected to a constant supply of power and it doesn't really matter how much they use. It's not even the PC itself so much as that big glowing box on your desk as opposed to that little, dull, low-power draining one that folds out of your laptop.

Take a look at the domestic UPSs that are available. You'll notice that they're rated in time they last for a given power load. Unplug the monitor from the equation and they'll last dramatically longer. Now look at the size of them and their relatively short lifetimes. For a PC, I'd be suprised if anyone could make a battery that'd power them and a monitor for any length of time that'd actually be small enough to fit in the case.

Remove the monitor from the equation, replacing it with a low drain equivalent (which is where a chunk of the laptop cost comes in) and assuming you can provide that for about normal desktop costs, whack on any domestic UPS and you've got your solution for the sort of money you're talking about.

Unfortunately, there's not a low drain monitor option for about the same cost/quality as a CRT.

Re:What about long power outages?

[ajs]

Laptops really are not all that expensive. If you compare the cost of your average laptop with the cost of a PC+monitor, the difference is around $500-$1000 depending on how ballsy your "average" machine is.

Now, take into account that some fraction of the users in most companies are also going to want laptops. Now, take into account that the laptops will continue working without power, without a UPS. Now, you're starting to add up some change.

Next you should think about your PC admin. The difference to him/her is that, instead of having a clunky box that you have to crawl under desks to service, you have a small box ON TOP of the desk.

All the way around, laptops are the best choice for most causual users. Designers tend to not like laptops because the LCDs suck, but that's a small (or absent?) portion of most companies.

Money's one constraint, safety's another.

[unitron]

The rather warm inside of a PC probably isn't the best place for a lead-acid storage battery. The average home or office probably isn't a great place to keep many of the lead-acid battery types mentioned (automobile, marine, golf cart, etc.) They might give a lot more minutes of power than the sealed gel type in UPSes, but in addition to coantaining liquid sulphuric acid, they give off hydrogen fumes when charging (and some not too wonderful fumes when discharging as well).

Despite all of the AC to DC to AC to DC conversions involved and efficiency loss each time, the current system of inserting a UPS inline between the wall socket and the PC power supply is probably the best compromise currently do-able. You save money on a standardized PC power supply, you don't have to worry about leaking acid eating up your motherboard or hard drive or the battery exploding inside your PC, spraying acid everywhere, or dying an early death because of the heat, and you can get as small or as large a UPS as your needs and budget dictate.