Power supply build quality pictorial. part 2

[Grave14]

Re: Power supply build quality pictorial. part 2

Crown CM-PS850 Superior anybody can talk about this power supply?

Low price. What is quality? They have about 10 models ...

Crown - what is the company? Who makes them for the power supply?

[Pentium4]

Re: Power supply build quality pictorial. part 2

So you don't have one, you're just curious and looking at possibly buying one?

[370forlife]

Re: Power supply build quality pictorial. part 2

Got any pictures or a link to a website/review site? Knowing most of these small, more localized companies it is most likely a poor quality, outdated unit that is far overrated.

[Grave14]

Re: Power supply build quality pictorial. part 2

Crown CM-PS850 Superior - only photos, no tests

Another PSU Crown - no tests:

Crown CM-PS450

Crown CM-PS600 Superior

Capacitors Cheng Cheng-X... Chang... ZHIFA

[PeteS in CA]

Re: Power supply build quality pictorial. part 2

Interesting. I can't speak any Slavic languages (some days I wonder if I can speak English) or read Cyrillic Script, but those are some good pictures. I wonder if the terminals on the AC inlet are adequate for 850W. A glass fuse for 12A or 15A? Is that safe? If that fuse blows, it might shatter and spread glass fragments inside the power supply. The input common mode inductor and X-capacitors are not installed - not good for conducted noise suppression. The Y-capacitors look like they could be safety rated parts, which is good. The heatsink on the bridge rectifier may be good. 1500uF is good capacitance for the input side electrolytics, if they really are 1500uF; being rated for 105C is also good. Being an unknown brand is not good, unless they are not stressed much. The two big input electrolytics, the big brown sleeved film capacitor and the IC that may be the PWM ("AZ7500EP", possibly a version of the venerable TL494) suggest to me: the inverter topology is half bridge; the switch frequency is under 50KHz; the switch devices might be bipolar transistors. I like the large main transformer and the fairly heavy heatsinks. The output inductors appear to use the lower loss type of the most common output inductor materials, which is good. The output wires block airflow to the output electrolytic capacitors to a degree that they will get very little cooling. Put together with those being unknown brand parts, that is not good.

So, you're in Kazakhstan, which probably means you have limited resources available to you. I'm not demeaning your country, just trying to think realistically. I think the least strong aspects of that power supply will be the output capacitors (unknown brand, poor airflow), the start-up capacitor for the PWM (a common point of failure) and the output capacitor for the +5V Standby output (another common point of failure). All that said, the power supply has some things that look good, and some things that look not so good. My guess is that if you load it with less than 600W and the fan doesn't fail (something to watch!) it should last for more than 3 years (possibly 5 years or more). The unknown brand capacitors are a concern, but so-so quality parts can last quite a while if only subjected to moderate stress. So if you think you will get a new computer in the next 3 or 4 years (or plan to buy another power supply), this power supply could suit your purpose.

I tried to avoid using American English slang and figures of speech, but if something I said is not clear, please do not hesitate to ask me to clarify my meaning.

[370forlife]

Re: Power supply build quality pictorial. part 2

Notice all the silkscreening by the fuses says "600W". It might do 600W based on the secondary silicon and by the size of that transformer and heatsinks. How well it does 600W is anyone's guess. Probably not well.

I agree that it is a Half Bridge design. It looks like a very close copy of an old SuperFlower design that actually did pretty well up until at least 700W. If you pay attention to component layout as well as the number of taps on the transformer, they are almost identical save a few of the input components, which easily could have been changed sometime in the platform's life.

EDIT: These small unnamed Chinese companies that appear all the time always, I mean always, screw up a good design in some way. Though the SuperFlower performed well, this knock off will not.

[Behemot]

Re: Power supply build quality pictorial. part 2

A glass fuse for 12A or 15A?

You would be surprised what power rating some glass fuses have…

[Grave14]

Re: Power supply build quality pictorial. part 2

Interesting. I can't speak any Slavic languages (some days I wonder if I can speak English) or read Cyrillic Script.........
..................

Thank you!
Selection of power supply units have small. A Crown 850W good price - $ 75-100
The rest are from PSU $ 200-300 (800W-900W)

*

[PeteS in CA]

Re: Power supply build quality pictorial. part 2

Notice all the silkscreening by the fuses says "600W". It might do 600W based on the secondary silicon and by the size of that transformer and heatsinks. How well it does 600W is anyone's guess. Probably not well.

I agree that it is a Half Bridge design. It looks like a very close copy of an old SuperFlower design that actually did pretty well up until at least 700W. If you pay attention to component layout as well as the number of taps on the transformer, they are almost identical save a few of the input components, which easily could have been changed sometime in the platform's life.

EDIT: These small unnamed Chinese companies that appear all the time always, I mean always, screw up a good design in some way. Though the SuperFlower performed well, this knock off will not.

Now you mention it, I think the half bridge topology is another good reason to keep this under 700W.

[Jooo]

Re: Power supply build quality pictorial. part 2

Crown CM-PS850 Superior - only photos, no test

I wouldn't trust it... It has something to do with these cheapo Alpine PSU's, I'm 99 percent sure they have the same manufacturer. Alpines have terrible reviews on Amazon.

http://www.amazon.co.uk/gp/aw/d/7135799380

Just look at the box:

Alpine:

Crown:

I think this might be the same PSU too: http://www.amazon.co.uk/gp/aw/d/B005FW0Q48

[lti]

Re: Power supply build quality pictorial. part 2

Nokia ACP-7U

Yes, that's it. There is no filtering.

The last picture shows the temperature protection device. It measures 0.1Ω at room temperature, and it appears to go open at 125°C. It wasn't touching any component, so I don't know how well it really works as a protection device.

[ddscentral]

Re: Power supply build quality pictorial. part 2

Judging from their website ( http://www.crown-cis.kz/ ), Crown looks like another no-name rebrand company to me.

I usually try to avoid anything coming from such companies because they mostly sell rebadged Chinese junk.

[kaboom]

Re: Power supply build quality pictorial. part 2

Judging from their website ( http://www.crown-cis.kz/ ), Crown looks like another no-name rebrand company to me.

I usually try to avoid anything coming from such companies because they mostly sell rebadged Chinese junk.

Absa-loopey!

"Crowns" of the late '90s were rebadged Deers. Model numbers weren't even "Crown" specific. That's right- "Crowns" would be LC-xxx-AT and LCB-xxx-ATX.

The "ATX" ones were even worse. They were in fact AT supplies, but with a little circuit board fastened to the top of the two heatsinks for 5VSB and AUX power.

Those AUX supplies were a bit unstable, so there was a large load resistor across its output. Needless to say, all of those little boards got quite discolored. And RFI? Fughettaboutit- buzzsaw city.

"Oh Deer."

[shovenose]

Re: Power supply build quality pictorial. part 2

The crown PSU looks like a mediocrely decent unit as long as you don't push it hard - except for a horrible cap selection!

[kaboom]

Re: Power supply build quality pictorial. part 2

The crown PSU looks like a mediocrely decent unit as long as you don't push it hard - except for a horrible cap selection!

What else is new?

[cheapie]

Re: Power supply build quality pictorial. part 2

Nokia ACP-7U

Yes, that's it. There is no filtering.

The last picture shows the temperature protection device. It measures 0.1Ω at room temperature, and it appears to go open at 125°C. It wasn't touching any component, so I don't know how well it really works as a protection device.

A linear phone charger? There must be a regulator in the phone or something.

[Pentium4]

Re: Power supply build quality pictorial. part 2

Crown CM-PS850 Superior - only photos, no tests

Cheap crap or not, holy hell that is one beefy half bridge unit! I think that's the first time I've seen 1500uF input caps

[c_hegge]

Re: Power supply build quality pictorial. part 2

Cooler Power GX850. Looks to be a CoolerMaster knock off. It isn't too bad, except that it's not an 850W. It made it up to 500W on the load tester before one of the two 12V rectifiers went out. Interestingly, though, I only had about 40A worth of 12V load. With a pair of 30A schottkys, I would have expected to be able to go a bit higher, even in forward topology. Maybe the fact that the PFC choke blocks almost all airflow off the secondary heat sink (and doesn't leave that grille space free) might have something to do with it. The secondary heat sink stayed too hot to touch long after the primary heat sink and other parts had cooled down. The caps are BH and GoldLink, and the fan is a 140mm Yate Loon Ball Bearing. Not bad for a no-name unit. I believe the OEM to be Golden Tiger.

When I fix it up, I'll replace the 12V schottky rectifiers with 40A parts.

[Wester547]

Re: Power supply build quality pictorial. part 2

I don't see a half bridge coupling capacitor on the primary side so I'm assuming that's forward topology. That means the secondary side's current ability rectifier wise is derated by 43%. With the PFC choke blocking airflow to the secondary heatsink and the secondary heatsink being too hot to touch for so long, it's no wonder the rectifiers shorted at 40A. Unless, of course, the schottkys in question are lying about their current ability. Those BH capacitors on the secondary side probably aren't helping anything, neither are the HEC primaries.

[domas]

Re: Power supply build quality pictorial. part 2

Nokia ACP-7U

Yes, that's it. There is no filtering.

The last picture shows the temperature protection device. It measures 0.1Ω at room temperature, and it appears to go open at 125°C. It wasn't touching any component, so I don't know how well it really works as a protection device.

Oh so many components inside! I think it might work with just 1 rectifying diode, why spend money on all 4?

It is not even switch-mode.

This sets a new standard for BAD.