Where are all the parts?

[Agent24]

Re: Where are all the parts?

Nice! Loving the Windows 3.1 styled clock too...

[weirdlookinguy]

Re: Where are all the parts?

Microsoft buys Skype
Case of irony.

[kaboom]

Re: Where are all the parts?

Skype even did microsux a favor. With skpye 5 and newer, 'skype' is just another skin for internet exploder.

After executing, it fills "tempor~1" with a bunch of crap. Have any of you tried 5.3 and then had trouble downgrading back to 3.8 or 4? I ask this because of what I've seen on 'puters I've worked on.

WLG, that was my reaction after 'exploring' around on a neighbor's computer, looking at the 'mess' left behind.

-Paul

[ratdude747]

Re: Where are all the parts?

guys- could you move the skype discussion to here:

https://www.badcaps.net/forum/showthread.php?t=14560

its off topic and my announcement thread has seen no views.

[Shocker]

Re: Where are all the parts?

I wouldn't put a 40V rectifier on the +12V in a half-bridge design. 60V minimum, 100V better. And why a 30A rectifier on the +12V in an old AT unit??? The original wires would not be aluminium, but tinned copper. Remember the dangers of aluminium wiring in homes???

I also have a 200W AT Hipro that looked decent, except that there was NO INPUT FILTERING when I got it. I eventually added filtering components I salvaged from other PSUs. The X capacitors are 2 x 0.33uF from L&Cs, the Y capacitors (2 x 2.2nF) and ferrite coil from a different Hipro.

The Hipro I got the Y caps and coil from is worthy of mention here. One of those special Compaq ones, +3.3V 15A, +5V 11A, +12V 5A, +12.8V 7.5A, 220W total. GBU6K bridge, 560uF Panasonic UP primary caps, STPS30L40CW for +3.3V, STPS1545CT for +5V, BYW99-W200 for +12.8V, P40NF0s for +5V and +12V. Nichicon, Chemi-con, Panasonic, Taicon secondary caps. Some small Teapo SEK scattered around the unit.

Anyway, back to the other Hipro. PBL405 bridge, 330uF Rubycon USP primary caps, 2SC4242 switchers. ESAC65-004 for +5V (couldn't find a datasheet), "C25M" for +12V. Secondary CapXon GL, 2200uF and 1000uF for +5V, 2200uF for +12V. None of them are bulging. The small caps are Teapo SK 85°C .

Remember Newbie2's L&C rebuild??? I might try rebuilding an L&C myself one day. Just out of curiosity. Any questions???

[Th3_uN1Qu3]

Re: Where are all the parts?

I wouldn't put a 40V rectifier on the +12V in a half-bridge design.

I've used 45v ones with no issues, and i've seen a couple designs where they had 45v ones from the start. It isn't going to hit breakdown unless your mains voltage is *very* high, and even so it would only do it at low load, because as load increases the voltage on the primary caps decreases when the PSU does not have PFC. At worst it'll create a little extra heat.

[Scenic]

Re: Where are all the parts?

Nice! Loving the Windows 3.1 styled clock too...

Attached it just for the heck of it.
If doubleclicking the .gadget file (in Vista/7) doesn't do anything, type "shell:gadgets" (without the quotes) into the start menu search bar thing and hit enter. That opens the folder where all gadgets are stored. Unpack it there and it'll then show up in the Sidebar gadgets thing in windows.

[sorry for OT]

[Shocker]

Re: Where are all the parts?

At worst it'll create a little extra heat.

Actually THIS can happen:

https://www.badcaps.net/forum/showth...?t=8171&page=7

All in a matter of 40 seconds.

If I do an L&C rebuild, I'll use at least a 60V rectifier. I have an S20C60C lying around.

You mentioned replacing KZG with KZE elsewhere. They aren't even somewhat close, and I wouldn't dare try it.

If you do it anyway, so be it. But if you tell people to do it, you should get banned from the forum.

[Th3_uN1Qu3]

Re: Where are all the parts?

If you want to be rigurous, scope the transformer at maximum mains voltage and zero load and see the peak voltage. Then you will know exactly what the voltage rating of the diode should be.

As for me being banned from this forum, let's let the administration decide, shall we? The forum has an ignore list you can use if you don't like to read my opinion.

[Shocker]

Re: Where are all the parts?

If you want to be rigurous, scope the transformer at maximum mains voltage and zero load and see the peak voltage. Then you will know exactly what the voltage rating of the diode should be.

As for me being banned from this forum, let's let the administration decide, shall we? The forum has an ignore list you can use if you don't like to read my opinion.

It's a case where "barely enough" is not enough.

BTW, I'm working on the L&C. PBL405 bridge in place of the 2A05 diodes, the 560uF Panny UPs, SBL2040CT for +3.3V, SBL3040PT for +5V, S20C60C for +12V, added pi coils (from three different PSUs) to all six outputs. The coil I chose for the +5V will make inserting the caps a bit of a squeeze. Don't even ask about jamming 12.5mm caps into there. The input filtering (excluding MOVs) was already in place.

[Shocker]

Re: Where are all the parts?

Oh and I know the ignore list. I already put bigcape on it. But I'm not ignoring you...yet.

[Agent24]

Re: Where are all the parts?

I never saw the point of ignore lists - well I can see the point - but blocking out what someone writes just because you don't like them doesn't really make sense to me.

I have never known anyone to always say things I never agreed with or which weren't useful.

In saying that I am not trying to be judgemental about anyone's potential blocklist decisions, just voicing an opinion!


On the other hand, I really can't see what's wrong with a 40v device on a 12v rail either. Surely 12v is far within the limits of 40v?

[goodpsusearch]

Re: Where are all the parts?

Actually, I remember at that psu that when I used the 30A schottky at 12V, the secondary heatsinks got very hot when I tested the power supply without load and that should have got me suspicious.

[Th3_uN1Qu3]

Re: Where are all the parts?

On the other hand, I really can't see what's wrong with a 40v device on a 12v rail either. Surely 12v is far within the limits of 40v?

It's due to the peak voltage of the transformer. A computer PSU is a regulated SMPS, and to keep regulation it needs to have some headroom built-in. In SMPS, regulation is done by varying the pulse width, the height (ie peak voltage) stay the same. If you disable the feedback loop of a PC PSU and let the controller run at max duty cycle you'll get something like 25v out, but you'll also get a ton of noise over it as there is no more regulation and the noise isn't smoothed out. This shows that there is headroom available at the transformer for double the output voltage or more. However, as load increases this becomes significantly less.

Needless to say, don't try this with the original caps in as they'll pop in your face.

Above those 25v there's also the voltage dropped across the output inductor, so yes, in some cases, the peak voltage available at the transformer can be higher than 45v. There's only one method that will show you what diode you need and it doesn't have to do with any rule of thumb as there are none. Scope it.

[PeteS in CA]

Re: Where are all the parts?

In SMPS, regulation is done by varying the pulse width, the height (ie peak voltage) stay the same.

IOW, the peak voltage of the square wave the rectifier sees (ignoring ringing and noise) is much higher than 12V, and varies with the AC line voltage. It could be triple or quadruple the O/P voltage, depending on the supply's designed minimum AC voltage and how the transformer was designed. Then there is ringing, which can go higher still. A conservative rating choice would be 100V or higher (and I am aware that the forward voltage will be higher, especially if an ultrafast rectifier is used). 60V will probably work OK, while 40V or 45V would be pushing your luck pretty hard.

[Agent24]

Re: Where are all the parts?

Thanks guys, that makes sense now

blocking out what someone writes just because you don't like them doesn't really make sense to me.

I have never known anyone to always say things I never agreed with or which weren't useful.

Probably should explain that ^ better - anyone could interpret that as a statement "I don't like you but I'll listen to you anyway" - I have no issue with anyone on this forum, so don't get me wrong and think I'm secretly hating anyone here!

[c_hegge]

Re: Where are all the parts?

In SMPS, regulation is done by varying the pulse width, the height (ie peak voltage) stay the same.

So that's essentially varying the duty cycle.

It's interesting that HardwareSecrets always say the duty cycle is typically fixed at 30% or so. Obviously, they are wrong if the duty cycle is in fact varied.

[Shocker]

Re: Where are all the parts?

Working on PSUs is fun

I added two MOVs and upgraded the +5VSB diode from a 2A to a 5A.

I can use a 1500uF Chemi-con KZH from DPS-350AB-7 (the same PSU I got the MOVs from) for the +12V. I don't have caps for the other outputs.

Also: 50th post!!!!!

[PeteS in CA]

Re: Where are all the parts?

The duty cycle is varied to compensate for line and load changes. That's how SMPS regulation is achieved.

[PeteS in CA]

Re: Where are all the parts?

The main reason for the duty cycle varying is line voltage changes. Load changes cause the duty cycle to change a little to compensate for the small voltage drop changes in the switch devices, rectifiers, windings in the transformer and inductor, and PCB traces.