Back again, Lower is higher also??

[newhit]

I've been browsing around the market for a high end PSU, 750-1000W. I've checked a few schematics of various PSU's and it seems that quite a few are the same for different models. Tagan 900/1100, Etasis 750/850, Enermax 850/1000, Xclio 850/1000. I think Silverstone have something similar with the Strider 850/1000. I realize that I do not have access to full cct diagrams to prove or disprove what I'm guessing at here and probably could not decipher the differences anyway if I had the diagrams but is there some devious plot manifesting itself around the manufacturers to get extra cash out of us by just putting a bit extra on the labels that cannot be disputed and so can be marketed legitimately.............errr, allegedly .

I am not making any accusations here, just querying the similarities that appear at first glance.

[madmat]

I'm not understanding what you're trying to convey. What exactly is your point?

PSU's don't do everything that they're rated for on the 3.3V, 5V and 12V rails? Is that it? If so, yes of course they don't. You've left out the 5VSB rail and the -12V rail. Those are consuming power as well. Granted it's a small amount but it is wattage nonetheless.

If you're trying to say that the lower wattage unit is the same as the higher wattage unit I've just gotta ask one question: What have you been smoking and do you share? No they're not the same. The design might be based off the same PCB and share a lot of the same circuitry and in some cases components but where it matters most, in the transformers, rectifiers and power MOSFETs you'll find that the lower wattage units have cheaper, lower spec'ed parts.

[jonnyGURU]

Originally Posted by madmat

What have you been smoking and do you share?

I'd just leave it at that.

[madmat]

ROFLMAO!

[Spectre]

Originally Posted by newhit

I've been browsing around the market for a high end PSU, 750-1000W. I've checked a few schematics of various PSU's and it seems that quite a few are the same for different models. Tagan 900/1100, Etasis 750/850, Enermax 850/1000, Xclio 850/1000. I think Silverstone have something similar with the Strider 850/1000. I realize that I do not have access to full cct diagrams to prove or disprove what I'm guessing at here and probably could not decipher the differences anyway if I had the diagrams but is there some devious plot manifesting itself around the manufacturers to get extra cash out of us by just putting a bit extra on the labels that cannot be disputed and so can be marketed legitimately.............errr, allegedly .

I am not making any accusations here, just querying the similarities that appear at first glance.

Ummmm?

So having various capacities in a model line is a problem?

Well don't ever buy a car...because performance options will blow your mind there.

[jonnyGURU]

If you're going to use the car analogy.... You have two cars with the same displacement (let's say 3.0.) One is a push rod and one has dual overhead cams (+12V rail) which has more horse power? They're both 3.0...

A lot of PSU's have the same 3.3V and 5V capability and it's often fairly low because computers don't use that much 3.3V and 5V.

A lot of PSU's have 20A on each +12V rail (if they have split up +12V rails) because as long as each rail is not capable of putting out more than 240VA, it's considered "ATX12V."

But most PSU's DO NOT have the same total combined output capability on the +12V rail. For example, look at the two Infiniti models:

http://www.jonnyguru.com/PSU/Infiniti720W/DSC00743.JPG

Both have 3.3V @ 25A, 5V @ 30A, total combined for 3.3V and 5V @ 160W and three +12V rails at 28A, 28A and 30A. But the total combined output of the +12V is 624W on the 650W and 672W on the 720W.

No conspiracy theory, please. The jet fuel weakened the steel that in turn caused the tower to collapse. The steel did not need to melt for this to happen, therefore there's no reason to theorize that the buildings were detonated by explosives.

[newhit]

OOPS!,

I realize I appear to have lost the plot but I definitely can see identical pcb's and transformer part numbers being used in different units. Is there some design factor that allows this to happen?

Madmat, I definitely saw the exact same trannies in use and, looking at the Etasis, the same PCB part numbers. But you are saying that the components are higher wattage. OK, that seems to be an answer.

I'm not leaving the planet, or hitting the substance abuse trail. It just seemed odd that's all.

I definitely don't want to cause ructions here. Thanx for the replies anyway.

[jonnyGURU]

Yes. It's very common practice to take an existing PCB and upgrade all of the parts to a higher output components. And higher output does not necessarily mean larger size.

[madmat]

Yeah, there are plenty of TO220 (I think that's the case designation at least) MOSFETs that vary in wattage but they're all the same case so they're the same size. The higher output parts cost more. Don't believe it? Hit up www.partsexpress.com and look up power MOSFETS for yourself.

[C'DaleRider]

I think what he's missing in all this is the viewpoint from a manufacturer's side.

If I were going to produce a line of power supplies and was trying to cover a fairly broad spectrum of price points....hence wattage outputs...how would I do it as economically as possible?

I could either produce a different pcb for my 750W, 850W, 900W, 1000W units......or use the same pcb for all of them.....thereby dropping my development and per-unit cost drastically, not to mention reducing my inventory costs.

I could spec a completely different transformer for each unit.....or I could use a higher spec transformer for most of them and maybe use a different for the higher output units.....like one for those under 900W and another for 900W and greater. So I 'd have only two to stock and keep track of instead of 6.....again, dropping my sourcing costs, development costs and inventory costs.

I'd most likely use as many parts over and over in all my supplies as I could...and I'd probably only change what parts I absolutely had to to meet the different outputs I had to produce. The fewer different parts the manufacturer has to use, the cheaper each unit becomes to manufacture.



Going back to the car analogy.......I guess he should be glad he wasn't buying cars back in the '60's through the '70's. He'd really have been seeing conspiracies with all the variants of engines and outputs from them....like all the different HP outputs from all the different 327's and 350's GM stuck in all sorts of vehicles. Of course, that 350 in the Chevelle SS wasn't quite the same as the 350 in the Impala station wagon, but they sure looked alike. Same with the big block 454......some were HP monsters, some weren't. But outwardly they all resembled one another quite uncannily. Even had a lot of the same accessory mounting spots and brackets.

I'm actually surprised he's not screaming about cpu speed markings since it's pretty general knowledge that cpus, like the Intel C2D cpus, are all from the same silicon and they are speed rated according to testing after production......those that pass at the highest speed needed, like 3GHz, are binned to that. Those that cannot pass muster there are binned downward until they pass....like at 2.16GHz. Of course, since Intel's yields seem to be so good right now with their parts, that may be one reason that the lowly e6300's are overclocking like mad, just like their e6700 counterparts. The low-rated parts may have passed at faster speeds, but since yields are so good, they just downrate the chips to lower speed rating for sale....since Intel knows they'll sell way more cheaper and "slower" cpus that the top-end and more expensive cpus.