Logisys 575W

[momaka]

Re: Logisys 575W

Good job! This PSU now looks much better. However, there are still a few things you can do to make this power supply complete.
First, add PI coils between the output caps (there are still a lot of jumpers there and that's not good). If this power supply has empty spots for more schottky diodes on the 5v or 12v rails and you have a junk PSU laying around, extract them from there and add them in this power supply. This will better distribute the heat on the secondary heatsink and you might be able to pull more current from each rail. Keep in mind, though, that with the transformer and primary switchers you have right now, you're going to be limited to about 250 watts total. Any more than that would not be safe.
As for the primary caps, 820uF is probably an overkill. 680uF should be adequate. Save a dollar or two from that and buy some small caps instead to replace the rest of the BH caps (if there's a 47uF or 22uF cap, make sure to replace that as those are important sometimes - example: Bestec PSU with bad 5vsb design). If you decide to replace the heatsinks, don't use steel.
Otherwise everything looks ok for a backup power supply. Nice work so far.

[370forlife]

Re: Logisys 575W

I just thougt, if they silk screened the board for all that, why not put it on?

etnietering, how much did it cost for all those parts?

[etnietering]

Re: Logisys 575W

@ momaka - Thanks for the advice - I have a question though:
for the Pi filters, do I need to find an inductor that is rated for the full capacity of the rail? There are two spots for them, the +5vsb (which is rated at 2A), and the +3.3v (which is rated at 28A). Finding a 2A inductor will be no problem, but finding a 28A inductor to fit in that tiny area probably will be.

I did find 2 47uF @ 50v caps, next time I order things I can replace them. Do they need to be the low ESR types, or will general purpose caps do? The rest of the electrolytics are all 2.2uF-10uF, do those need to be replaced too?

For the primaries, I just measured the space and found the biggest ones I could stuff in there. getting the 680uF ones will save me about a dollar.

It does have space for another 12v rectifier, and I do have some junk PSUs sitting around, but I don't think I have the tools/skills to take the (relatively) big heatsinks out and get them back in and have it work right. If I'm feeling brave though, I can give it a shot.

@370forlife - I imagine they use the same board for several power supplies (mine has 'ATX-2000' on it like somebody else mentioned), but for the cheapy ones (this was $15), they don't populate the unnecessary components. The costs went as follows:
Panny FM 680 @ 16 - $0.316 x4 = $1.304
Panny FM 1200 @ 16 - $0.45 x2 = $0.90
Panny FM 1500 @ 10 - $0.45 x2 = $0.90
Panny FC 2700 @ 6.3 - $0.756 x2 = $1.512
X cap - $2.30
Y caps - $0.318 x2 = $0.636
Coils - Free!
bleeder resistor - a couple cents

for a total of $7.552

and the work left to be done on it:
1x 6A 1000v bridge rectifier (I decided the 8A was overkill) - $1.79
2x Panny TS-ED 680uF @ 200v - $7.62
2x 47uF @ 50v - a dollar maybe
and the other inductors will cost a few dollars, unless I can find them for free from coilcraft

oh also - I went with panasonic for the x and y caps. I've found though that if I go with vishay for these, I can get them for about half as much. is it possible to have good and bad capacitors of these types? Or are they all the same, and I'm just wasting money getting the panasonics?

[ratdude747]

Re: Logisys 575W

Ohh ya, it actually is a deer, but actually a nicely built deer if it weren't for the caps.

see i was right

still, a few deers ore ok after a recap, i hope you recapped it.

[370forlife]

Re: Logisys 575W

It still has the original YC caps

Rails are still stable and it does its job well(ish) still.

I would rather have the deer version vs the ATNG version, the ATNG had Fujiyuu on the secondary.

[ratdude747]

Re: Logisys 575W

It still has the original YC caps

Rails are still stable and it does its job well(ish) still.

I would rather have the deer version vs the ATNG version, the ATNG had Fujiyuu on the secondary.

doesnt matter which brand, they both suck. recap that thing and be done with it.

[370forlife]

Re: Logisys 575W

I'd have to say YC is better than fujiyuu due to their super sensitivity to heat.

Besides, non are bulged and all the rails are in spec under a ~250W load. I won't worry about it until the shit hits the fan, especially since its just a backup (what my free TP550 will be soon anyways...)

[ratdude747]

Re: Logisys 575W

exept when the shit hits the fan so does your cpu/mobo half of the time

[KeriJane]

Re: Logisys 575W

YC caps taking out the Motherboard & CPU?

Only after they get a couple of Hard Drives first and someone starts hollering about how crappy Hard Drives are nowdays....

Then the motherboard.

Never seen a CPU get it recently though. I saw one of them bad 'ol Athlons with no overtemp protection.... someone knocked off the heatsink (maybe by dropping the pooter down the stairs?) and FOOM! CPU bonfire!
(Keri! my computer smells funny!)

Have Fun,
Keri

PS. Does anyone want a jellybean jar full of pretty YC caps? Well, OK, it's not especially full. But it will be someday!

[momaka]

Re: Logisys 575W

for the Pi filters, do I need to find an inductor that is rated for the full capacity of the rail? There are two spots for them, the +5vsb (which is rated at 2A), and the +3.3v (which is rated at 28A). Finding a 2A inductor will be no problem, but finding a 28A inductor to fit in that tiny area probably will be.

Yes, they do have to meet the full capacity, but if you have some junk PSUs that you're not going to use, see if they have those PI coils. Usually the 5v PI filter will also fit 3.3v. But if you can't find any, you can make your own if you have some thick copper wire (make sure it's close enough in thickness to the 5v coil) - just find a round object that's 3mm in diameter or more and wind the wire around it (untill the winding is 20-30mm in lenght), then soldier the wire ends to the PSU and remove the object. End result should be a core-less PI filter. I've seen one like that on the 3.3v rail of an old but well built Morex PSU. Since it's core-less, it doesn't have much inductance, but I guess it's better than jumper wire anyways. It's also recommend you put glue on the coil - this should prevent vibrations and high-pitched noise.
5vsb PI coil should be easy and inexpensive to get online.

I did find 2 47uF @ 50v caps, next time I order things I can replace them. Do they need to be the low ESR types, or will general purpose caps do? The rest of the electrolytics are all 2.2uF-10uF, do those need to be replaced too?

Yes, these caps should be low ESR. KY and KZE (United Chemicon), PW and HE (Nichicon), or FC and FM (Panasonic) should all be suitable replacements.
The 2.2uF-10uF electrolytics don't need to be replaced as they almost never go bad. But you can if you want to.

oh also - I went with panasonic for the x and y caps. I've found though that if I go with vishay for these, I can get them for about half as much. is it possible to have good and bad capacitors of these types?

Those caps are for safety and line suppression, but they almost never fail. As long as you're not getting a cheap one with no safety approvals, you should be okay. Vishay is a well known company, their X/Y caps should be as good as the Panasonics.

And by the way, don't bother with the 12v rectifier. You're right, it's just too much work.

PS. Does anyone want a jellybean jar full of pretty YC caps?

Sure, why not. I have an old Deer with blown Viva caps on the 3.3v that could use some updating. A Deer is not complete without the YC caps nowadays .
Shipping will probably cost more than a bag of new *good* caps, though.

[etnietering]

Re: Logisys 575W

ok, well, I finally got everything ordered that I needed, and finished turning my POS into something you might actually be able to use. the rest of the replacements went as follows:

input caps:
2x fuhjjyu 470uF @ 200v -> 2x Panny ED 680uF @ 200v

output caps:
2x BH 47uF @ 50v -> 2x Panny FC 47uF @ 50v

+5vsb Pi filter:
jumper -> 6.8uH 3.5A inductor

+3.3v Pi filter:
jumper -> crazy coil I found in my desk

bridge rectifier:
4x 3A 1000V diodes -> 1x 6A 600V real bridge rectifier, upon which I put heatsinks made from Dr Pepper cans.



And now for my favorite part, the pictures

All the parts I put in - huge input caps, little output caps, mega inductor, not so mega inductor, and the bridge rectifier


Got everything on the secondary side done - you can see the copper colored mega coil, the littler coil between the two big black caps, and just the top of one of the little caps to the left of the black ones, the other is right next to it


Giant new input caps one of the fuhjyyu's was bulging a at the top! yikes!


And here's the new bridge rectifier, with the strange heatsinks that resemble a squid.


Here's a top down shot, you can see all the latest improvements, as well as the LEDs I added last time, and you can almost read the dr pepper logo


And then I started playing with my macro settings, and got this neat picture. It's a lot more impressive at 9MP though...



I wish I had an oscilloscope, to see how much of an improvement all of my work made. Oh well...I would actually feel confident using it as a low power backup now, which was the whole idea. On the package that the input caps came in from digikey, it said the country of origin was the USA. How crazy!

Thanks everybody for all the help

[momaka]

Re: Logisys 575W

Nice work there! It's much more respectable now. Shouldn't have problems with ripple and noise even at 200-250 watts.
By the way, have you tried powering it on yet? Hopefully those upgrades kicked that little Logisys devil out of the power supply .

[ratdude747]

Re: Logisys 575W

damn those are wimpy heatsinks...

[370forlife]

Re: Logisys 575W

Regarding the heatsink:

http://www.allelectronics.com//index...&p=1&template=

[Newbie2]

Re: Logisys 575W

I think I got competition here!

Too bad I can't get my bridge rectifier to work right in my L&C unit (it buzzes for an unknown reason) and secondary side inductors are something I don't have and I don't have any good thick copper wire to make a cheap one.

But still, after my L&C is beefed up, I want a showdown! L&C vs. Logisys!

[Newbie2]

Re: Logisys 575W

damn those are wimpy heatsinks...

I don't think the bridge rectifier even needs a heatsink, all power supplies I've seen don't have one. His Dr. Pepper can heatsink is a little extra.

[etnietering]

Re: Logisys 575W

@momaka - thanks! I trust it a lot more now. I did have it powered on, and was pulling almost 80 watts from the wall running a bunch of fans and some CCFLs. I also found another X cap in a junk power supply, which I added to the power cord socket. I still wish I had an oscilloscope so I could see what benefits I get from all this though...

@ratdude747 - do you mean the ones I made, or the ones it came with? well, they're both wimpy. I agree with Newbie2 that the bridge rectifier most likely doesn't need a heatsink (something else would shut down/blow long before it), but I wanted to see if I could make something resembling a heatsink out of a pop can. And more cooling = better, so why not?

@Newbie2 - I still need to build a load tester thing....but then sure we can have a battle of the crappy PSUs

[370forlife]

Re: Logisys 575W

I don't think the bridge rectifier even needs a heatsink, all power supplies I've seen don't have one. His Dr. Pepper can heatsink is a little extra.

Usually only needed in units about 550W and over.

The seventeam thundering 1000W just has three bridge rectifiers without heatsinks than two with a heatsink.

[momaka]

Re: Logisys 575W

The power supply's heatsinks aren't that wimpy really. I have a 300 watt Macron Casing power supply and the heatsinks are almost the same (and I'm pretty sure that thing will do 300 watts as Macrons are known good). So I think your heatsinks are adequate too.
The bridge rectifier heatsink is not needed, though. Besides, cans are too thin to make into heatsinks (probably no heat transfer too). There's also a posibility of the long fins shorting something, so I would just remove it.

Other than that, your power supply is done. Addition of the second X cap was good idea.
----
I have some power supplies too that I'm planning on upgrading. We really should have a match or something (but I don't know when I'll work on mine).

[etnietering]

Re: Logisys 575W

ok I took your guys advice and removed my cheesy heatsink from the rectifier. I knew from the beginning that with that psu, I probably didn't need it, but I didn't think it could make things worse. It's rated for 6A, and there's no way that piece of junk is going to be pulling that much current...

I took some pictures, but at the moment my main computer is out of commission - windoze didn't like being copied to an SSD >_< I'll upload them once I get it back running

The X cap that I put in is .47uF, and added to the .33uF one I put in before that makes a total of 0.8uF This one I got out of an ancient AT power supply....it could very well be as old as me!