Power supply build quality pictorial. part 2

[Behemot]

Re: Power supply build quality pictorial. part 2

No, that wouldn't help. It's more to do with the topology. It's a flyback converter, not a forward converter, which produce far more ripple.

Oh, a single transistor in there, I can see it now…

[tom66]

Re: Power supply build quality pictorial. part 2

Flyback at 350W??

You do get single switch forward, you know, among other topologies.

With ripple current through the caps being a concern (it is often designed so they can use cheapest off brand cap possible) no one would make a flyback computer SMPS... right? Please tell me no one has tried to do so...

[Behemot]

Re: Power supply build quality pictorial. part 2

Yeah, could be single-transistor forward as well, you are right, just thought c_hegge had it in his hands before you see…

[lti]

Re: Power supply build quality pictorial. part 2

http://www.jonnyguru.com/forums/show...2548#post62548

I don't know what they did to get that kind of ripple.

[c_hegge]

Re: Power supply build quality pictorial. part 2

http://www.overclock.net/t/1310456/p...00w-psu-review

Phaedrus reckons it's a flyback, not single forward, which would explain the ripple. It would also explain why Leadmen often explode under <250W Loads

[Behemot]

Re: Power supply build quality pictorial. part 2

The fuse might be counted as OPP or SCP, but since it's rated way too high for the 250W we have here, I'm not counting it.

[c_hegge]

Re: Power supply build quality pictorial. part 2

Yah. I thought the same thing. I'm sure Leadman probably think that the fuse will be fine as OCP, though

[tom66]

Re: Power supply build quality pictorial. part 2

It's often hard to tell them apart; the only difference is a flyback of that size would need a massive energy dump resistor. A forward converter would use a single return diode.

[Wester547]

Re: Power supply build quality pictorial. part 2

And it has a pretty good transient filtering stage The only reason I'm using it is because it has such a low load to power. I have a Hipro with the same exact specs on the label as yours, but it has 470uf 200V Elite caps on the primary, all the rest are Teapo. Mine was manufactured in May, 2007. They're good little supplies. Efficiency is meh, I got 72%-76% out of mine. It powered a Pentium D, 2GB RAM, 7300GT, and 3 hard drives no problem for over a year, other rigs it was in used less power and it's still kicking.

I know this is very far back, but... I'm curious... often, PSUs will be below 70% efficient when the load is very light... did you get 72% efficiency out of that PSU even with a very light load (when the computer was idling)?

[Pentium4]

Re: Power supply build quality pictorial. part 2

That was under low to medium load. The computer that idled around 55W, the PSU only got around 69% efficiency, 76% was around 50% of its labeled wattage

[Shocker]

Re: Power supply build quality pictorial. part 2

No, I don't think it would be a flyback like everyone else suggested. If it was then it wouldn't have the large toroid.

[japlytic]

Re: Power supply build quality pictorial. part 2

Power Systems PS-1715 from LeCroy 93xx scope

470uF 200V Nichicon GF x2 prinary side units.
820uF 6.3V Nichicon PF for soft starting.
2200uF 6.3V Nichicon PL before and after +5.2V (6A) and -5.2V (8A) output inductors.
220uF 35V Nichicon PL before and after +15V (4.5A) and -15V (4.5A) output inductors.
1000uF 25V Nichicon PF at 15V fan output.

UF5402 x2 (in common cathode configuration) each for +15V and -15V rails.
SB540 x2 (in common cathode configuration) for -5.2V rail.
20CTQ040 for +5.2V rail.

MAC228A AC adaptation TRIAC with MJE13003 driver.
MJH16006A primary switcher with BUK454-800B auxiliary switcher.
KBU6J primary rectifier.

Even the monitor section (made in Taiwan) used quality Japanese electrolytics.

[PeteS in CA]

Re: Power supply build quality pictorial. part 2

IIRC, the 93xx LeCroy scopes were from the early 90s. The MJH16006 is a bipolar transistor. The original MJE1300x series was dubbed by Motorola the "Switchmode series" the first series of parts they designed specifically for SMPSs (the MJE1300x was in TO-220, while the TO-3 - actually, TO-204, but the difference is subtle - parts were the 2N654x). There was a Switchmode II series, and the MJE1600x was Switchmode III series; "MJH", IIRC, means a TO-247 package. At the time this P/S was designed, Nichicon's PL series was probably its best Low-Z series; with RoHS compliance. the series name was changed to PM.

[SuperDuty]

Re: Power supply build quality pictorial. part 2

An early 90's Phihong PSA-1454 145W AT power supply, that thing is built like a tank, the case is made of 1mm thick steel ! It came from an unbranded case from a local assembler, and if I recall correctly, it was powering a TI 486DX2-80 based system.



The fan is a ball bearing Matsushita brushless fan.
Primary caps are large 200V 470uF Nippon Chemicon, the rest are a mix of Rubycon and Nicon (are these good?).




The main transformer is huge for such a low power :


Overall a very nice quality PSU. The weird bit is that the wiring is coming out of the side of the case instead of the back.

[Behemot]

Re: Power supply build quality pictorial. part 2

Nicon is not a good brand I think, and 1 mm steel is pretty common amongst mediocre and better PSU's.

[c_hegge]

Re: Power supply build quality pictorial. part 2

Looks reasonably well built. At least the caps are adequately sized for the job, even if they aren't the best brand.

[Wester547]

Re: Power supply build quality pictorial. part 2

I have a question about APFC PSUs... since (if I'm not mistaken) an APFC design increases the ripple frequency on the output as well as the input, does that mean with a half-wave rectified output (single ad two switch forward) and schottky barrier rectifiers on the secondary that the freewheeling diode is still necessary in APFC PSUs (to avert reverse voltage spikes because of half-wave rectification on the output), on the secondary, or is it different?

[Behemot]

Re: Power supply build quality pictorial. part 2

Freewheeling diode has nothing in common with PFC at all. It has to be there to close a circuit where secondary inductor acts as a voltage source. This circuit works when switcher is off and no power is being transmitted to secondary.

The power is basically transmitted in bursts which than power the load on secondary and also charge inductor. When no power is transmitted, inductor discharges. This lowers output ripple as otherwise there will be no power at all when switchers are off and power is not transmited, resulting in regular voltage drops. You could deal with that using huge bulk capacitance, but it is somewhat non-practical as you can use just inductor and reasonable sized caps…

I have thee feeling I have already told you this, haven't I? Maybe it was not that clear…

[SIDMX]

Re: Power supply build quality pictorial. part 2

Acteck/Edge Systems AFB500-P 500W

Primary caps-------2x 560uf/200v
5VSB Switcher-----2N60
Primary Switchers --2x JME13007
12V Rectifier-------Mospec F12C20
5V Rectifier--------Mospec S16C45
3.3V Rectifier------Mospec S10C45
5VSB caps----------2x 470uf/10v
12V caps-----------1000uf/16V
-12V caps----------470uf/16V
5V caps------------1000uf/10V
3.3V caps----------2X 1000uf/10V

Well there's not so much to tell about this POS except that this thing actually shutdowns and don't explode when overloaded or shorted, all caps are ChengX and sadly the market in my country is flooded by this lousy brand/type of PSUs, in fact it is the most used in generic PCs, altough not by me.

It looks to me like a 180W-200W PSU but what do you think ?

[Behemot]

Re: Power supply build quality pictorial. part 2

With some modifications it may do 350 W quite fine, 400 W max.

At what power does it shut down?