Power supply build quality pictorial. part 2

[Pentium4]

ePower EP-550P5

Speaking of ePower...this one has been sitting in my room for a long time so I finally decided to recap it. At first I thought this looked really overrated for 550W. But it almost seems like it could be 500W with 550W peak.

It uses double forward topology. The bridge rectifier is 15A. The crazy thing is that it's rated for 15A with a heatsink, and only 2.1A without a heatsink, so I added one to it. The two FETs on the primary are 18A. The two Fhy caps read ~820uF. The interesting thing about them is that they read very low ESR for primary caps. They both read 0.02Ω.

The secondary silicon consists of two 30A schottkys in parallel for the 12V, and a 40A rectifier each for 5V and 3.3V. It looks to me like there was an option to have two rails on this unit but they decided not to install the OCP shunts by the wires.

Check out the mangled 5VSB wire! Fixed that too. Gave it all new caps. Just from sitting for 4 years, the Asia'X caps were starting to fail. They all tested good ESR but their capacitance all were outside 10% tolerance, some being 15% out of tolerance already, all on the high side of course.

That white fan connector is cool because it splits to two 3 pin fan headers, and two molex connectors with just 12V and com, and sends 5.67V to all of them. I tried testing it with a very cheap chinese fan, and the thing couldn't even start with 5.67V, how sad is that? I have some quality sleeve and ball bearing fans that would start up with as low as 3.5V.

[Wester547]

Re: ePower EP-550P5

The bridge rectifier is 15A. The crazy thing is that it's rated for 15A with a heatsink, and only 2.1A without a heatsink, so I added one to it.

Those ratings in the datasheet are without any airflow, with the assumption that the bridge rectifier will rely upon convection cooling. With the added airflow of the fan and that heatsink, the bridge rectifier could probably do 20A continuously, assuming the other components are up to it of course. Without a heatsink, it could probably do 4A or a bit more with the airflow at hand.

The interesting thing about them is that they read very low ESR for primary caps. They both read 0.02Ω.

Well, as you well know, ESR depends heavily on the length of the leads, the thickness of the dielectric, and the conductivity of the electrolyte. Also, some degree of drying up must occur after the companies who produce these capacitors (namely the good ones) run those standard torture tests and then measure the capacitors at room temperature or lower. IMO, assuming they are new or NOS, electrolytics, with their leads cut short, would ideally have an ESR value that's lower than that of the datasheet (the datasheet does list the values as "maximum"). So I'd say it's normal. ESR will also decrease with higher ambient temperatures and increase with lower ambient temperatures.

And those Asia'X probably read high capacitance because the dielectric on their anode thinned from having them just sit for 4 years. That, or the electrolyte is becoming aggressive toward the rest of the materials, the dielectric and aluminum foil included.

[Pentium4]

Re: ePower EP-550P5

Those ratings in the datasheet are without any airflow, with the assumption that the bridge rectifier will rely upon convection cooling. With the added airflow of the fan and that heatsink, the bridge rectifier could probably do 20A continuously, assuming the other components are up to it of course. Without a heatsink, it could probably do 4A or a bit more with the airflow at hand.

Cool, thanks for clearing that up for me. Even 8A with a heatsink probably would have been suitable in this application. It's nice to see overspeccing parts though, especially from hit or miss companies like ePower. By the way, they need to update their website SO BADLY. Look on their main web page ( http://epowertec.com/ ) under "New Product" and then when you click on "More" and then click on "Download mail in rebate form" It shows "Request must be postmarked before June 17, 2005" I attached a pic in case they take it down:

Well, as you well know, ESR depends heavily on the length of the leads, the thickness of the dielectric, and the conductivity of the electrolyte. Also, some degree of drying up must occur after the companies who produce these capacitors (namely the good ones) run those standard torture tests and then measure the capacitors at room temperature or lower. IMO, assuming they are new or NOS, electrolytics, with their leads cut short, would ideally have an ESR value that's lower than that of the datasheet (the datasheet does list the values as "maximum"). So I'd say it's normal. ESR will also decrease with higher ambient temperatures and increase with lower ambient temperatures.

Yeah, I'm just used to seeing 0.08-0.13Ω ESR on high voltage caps. And these ones aren't the cheesy regular styled lead HV caps, they're actually snap in.

And those Asia'X probably read high capacitance because the dielectric on their anode thinned from having them just sit for 4 years. That, or the electrolyte is becoming aggressive toward the rest of the materials, the dielectric and aluminum foil included.

Or both, because it's Asia'X "quality"

Most of the thinning probably occurred on my watch. When I acquired this PSU, those caps were 2 years old. Now they're 4 1/2 years old. Most of the date codes on them were from the 6th week of 2011. I will let them sit longer and see how they test in 6 months to a year.

[Wester547]

Re: ePower EP-550P5

Cool, thanks for clearing that up for me. Even 8A with a heatsink probably would have been suitable in this application. It's nice to see overspeccing parts though, especially from hit or miss companies like ePower. By the way, they need to update their website SO BADLY. Look on their main web page ( http://epowertec.com/ ) under "New Product" and then when you click on "More" and then click on "Download mail in rebate form" It shows "Request must be postmarked before June 17, 2005" I attached a pic in case they take it down:

That's funny. But this gem from the web archive might be even funnier for you:

http://web.archive.org/web/200610250...m.tw/about.asp

Notice what Sacon says on their old website...

"We might not be the most experienced --- but our technology is definitely the best!!"

Or both, because it's Asia'X "quality"

I just came to the realization that the capacitors are only 4.5 years old in terms of shelf life. That's appalling, they're already reading high capacitance. I think it's safe to call those Fuhjyyu clones failed.

[LDSisHere]

Re: Power supply build quality pictorial. part 2

I picked up this server power supply at work just before someone threw it out. I wanted to pull it apart to see what was in it and I figured I would share it here even though it is not an ATX supply. I did not bother to figure out how this supply worked, as I had no need to repair it.

I am going to let the pictures speak for themselves but I have to say I was very surprised to find a full blown PIC micro-controller in the middle of this supply.

[Behemot]

Re: Power supply build quality pictorial. part 2

Can still get lot of nice silicon from it…all DC-DC.

[LDSisHere]

Re: Power supply build quality pictorial. part 2

Can still get lot of nice silicon from it…all DC-DC.

You are right about all the goodies I can scavenge. The boards and parts are all being kept that is for sure. Those big caps and FETs can be expensive to buy. There are also a lot of TO-220 package devices I have yet to remove.

One of the big 20N60's was shorted and probably lead to the failure of the supply.

The complexity of this supply blew me away. When the daughter boards have daughter boards (granddaughter boards?) you know there is a lot going on and a lot of effort was put into the design.

[Agent24]

Re: Power supply build quality pictorial. part 2

I suppose it has to be complex when it's pushing over 100A on 12v!
And no wonder the fans are 11,000 RPM...

[momaka]

Re: Power supply build quality pictorial. part 2

Would still be worthwhile fixing, IMO (maybe don't sweat putting too much effort into it, but try the simple stuff first, and if it works... great!). With 100 A on the 12V rail, you can use it to power a car amp in your house, like this guy:
https://www.youtube.com/watch?v=U__WjDU92Kk
...
or for welding

[pfrcom]

Re: Power supply build quality pictorial. part 2

Acquired these two recently - seem like reasonable quality to me - interested to know what the power supply aficionados think of them

Asus A-36F
First three pics - apologies for the blurriness
Teapos in the secondary look OK

Task TK-940TX
Last four pics
Snazzy dual fans with wire grilles
Secondary caps look OK - couple look like Elna vent pattern

[c_hegge]

Re: Power supply build quality pictorial. part 2

Oh 'deer' me, that task has Koshin caps . It does look pretty well designed otherwise, though, especially for something from deer season. It might even do 400W (although I'd be reluctant to push it past about 350W, depending on the silicon)

[Dan81]

Re: Power supply build quality pictorial. part 2

Oh 'deer' me, that task has Koshin caps . It does look pretty well designed otherwise, though, especially for something from deer season. It might even do 400W (although I'd be reluctant to push it past about 350W, depending on the silicon)

I have a Fortrex ST-400W (Deer) built like that Task. It's the 2003 design though,despite datecode being 2005 (05N). Based on the following info,will it do 400W?

Info:
D13009K switching transistors
2N60 5VSB transistor
3.3 and 5v have SBL3040PT both
12v has UF1002FCT (10A ultrafast) - going to replace it with a S20C45 or SC20C60
EI-33 ASH transformer
PI coils
Approved Y caps (they have RU markings and all that stuff)
20AWG wires for everything

Any chances to have it put out at least 300-350W if not 400W? It has the same big heatsinks,they're thick like Bestecs,and you're not going to hear this anywhere but I found real X caps,with the RU logo and stuff.

Came with a worn out Xinruilian fan and a boring grille on the back. I cut out the grille and put another one along with a AVC DS0802512UP033 fan that has a "1B1S" bearing.

It apparently has been already recapped as 5vsb uses 1000uf 16v Panny FL (2x).Secondary caps are mostly Rubycon ZL and one MHZ,along with 2 Teapos. AC receptacle is mounted on a small PCB,presumably PPFC.

Basically,it's a mix of TELVM's Tuallin (LC-B350ATX) and goodpsusearch's Deer DR-A300ATX,since the secondary heatsink has that L shape to make room for the huge PFC choke. Primaries are blue 470uF 200V YC caps.

Also,the fan uses a 2 pin connector,but on this PCB (X-B2002 Rev:2.3) they seem to have traced the + pin to 5v as opposed to 12v on the Y-B200ATX versions. Good thing,as the AVC literally sounds like a hairdryer when on 12v. It sounds nice on 5v though.

[goodpsusearch]

Re: Power supply build quality pictorial. part 2

250W continuous, 300W max

[pfrcom]

Re: Power supply build quality pictorial. part 2

No comments on the Asus A-36F ?

Here's better pics

[c_hegge]

Re: Power supply build quality pictorial. part 2

It looks decent, probably capable of 360W. I can't tell for sure who the OEM is. It kind of looks like a HEC, but hard to say. Enhance is another possibility.

[Behemot]

Re: Power supply build quality pictorial. part 2

It's Enhance Electronics.

[goodpsusearch]

Re: Power supply build quality pictorial. part 2

Enhance. Decent, worth recapping!

[c_hegge]

Re: Power supply build quality pictorial. part 2

Of course. I can see that with the black and white main wires. The heatsinks got me. I'm used to enhance using those massive heatsinks with fingers everywhere (like http://www.overclock3d.net/gfx/artic...084641659l.jpg).

It's definitely a keeper, though.

[Dan81]

Re: Power supply build quality pictorial. part 2

250W continuous, 300W max

With the current 10A 12v rectifier it has?

[goodpsusearch]

Re: Power supply build quality pictorial. part 2

I wasn't referring to the secondary section of the psu. The combination of 33 sized transformer and 470uF primary capacitors (assuming they are real 470uF caps and not 330uF) makes it a 250W power supply.