Cheap PSU: Piece of junk or semi-decent?

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

I've included two big 680uF Panasonics in the order, just to be sure.


While the caps arrive I'm considering other tweaks. This Allied PSU came with a daughterboard soldered to the main connector with some transient filtering elements:

Guess the two yellow things are Y-caps (one is live on earth, the other neutral on earth), but they are very small. Is it worth replacing them with two larger cyan Y-caps I have around?

I could replace the ferrite coil with a larger one scrounged from other broken PSU's output area. Would this be coherent, or nonsensical?


I'm also adding a rocker switch, as this PSU came without switch but with an extra female header for a monitor. I've extracted the female header and are fixing the rocker switch in the vacant hole.

It's a scrounged SPST switch and my idea is to solder a piece of black live wire from the daughterboard to one pin of the switch, then from the other pin of the switch to the PCB (as I've seen in other PSUs with switch). Will this be OK, or I better get a DPST switch for both live and neutral?

[goodpsusearch]

Re: Cheap PSU: Piece of junk or semi-decent?

I've included two big 680uF Panasonics in the order, just to be sure.


While the caps arrive I'm considering other tweaks. This Allied PSU came with a daughterboard soldered to the main connector with some transient filtering elements:

Guess the two yellow things are Y-caps (one is live on earth, the other neutral on earth), but they are very small. Is it worth replacing them with two larger cyan Y-caps I have around?

I could replace the ferrite coil with a larger one scrounged from other broken PSU's output area. Would this be coherent, or nonsensical?

The winding of the coil in the photo is made of wire. This is as lame as it gets. I would definitely replace it.

Those Y caps are not real Y caps, safety approved. If you have real Y caps available (they are blue) replace them.

I'm also adding a rocker switch, as this PSU came without switch but with an extra female header for a monitor. I've extracted the female header and are fixing the rocker switch in the vacant hole.

It's a scrounged SPST switch and my idea is to solder a piece of black live wire from the daughterboard to one pin of the switch, then from the other pin of the switch to the PCB (as I've seen in other PSUs with switch). Will this be OK, or I better get a DPST switch for both live and neutral?

It will be ok. Just be careful not to accidentally touch the internals while connected to AC.

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

Thanks! About the replacement transient filtering coil, the larger the better?

[goodpsusearch]

Re: Cheap PSU: Piece of junk or semi-decent?

Yes, why not?

[momaka]

Re: Cheap PSU: Piece of junk or semi-decent?

The winding of the coil in the photo is made of wire. This is as lame as it gets. I would definitely replace it.

Those Y caps are not real Y caps, safety approved. If you have real Y caps available (they are blue) replace them.

Agreed

It's a scrounged SPST switch and my idea is to solder a piece of black live wire from the daughterboard to one pin of the switch, then from the other pin of the switch to the PCB (as I've seen in other PSUs with switch). Will this be OK, or I better get a DPST switch for both live and neutral?

Depends on the type of AC plugs you have on your walls over there. According to Wikipedia you have types C (2 pin Europlug for ungrounded appliances) and type F (Exactly like Schuko, but the ground pin makes it polarized). For these, I think it will be okay to have SPST. However, if you have any Schuko type plugs (where the Neutral and Live can be switched around, depending on which way you plug in the plug), then DEFINITELY go with the DPST switch (or don't put one at all)!

About the replacement transient filtering coil, the larger the better?

Most of the time yes. *Usually*, bigger coil means more turns on it, and more turns means larger inductance (hence better capability to filter bigger voltage spikes and dips).

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

Done. To make room for the larger ferrite coil I've used ©c_hegge™ trick of moving the X-cap to the backside.

Added a ferrite bead.

The rocker switch nested inside the gutted female header.

[momaka]

Re: Cheap PSU: Piece of junk or semi-decent?

Pretty cool! Now you have real Y caps and a real coil in there. The switch in the monitor plug is the coolest thing, though - I bet no one will ever have a PSU like that.
I'm guessing this is going in the computer you posted in the "ghetto mods" thread?

Speaking of which, I have a lot of stuff to post in that thread as well.

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

... I'm guessing this is going in the computer you posted in the "ghetto mods" thread? ...

Yep, this PSU is for the dinosaur PIII .


The fresh caps arrived .

It's going easier than I expected , except for the two little ones between the heatsinks. They were a PITA and needed tweezers & lots of harsh language to go into formation .

->LARGE · ->LARGE · ->LARGE

I'm leaving the n.16 2200uF 16V 12.5mm Ø for the end, to have room for fixing my resistor-cooling ghetto-mod. Also the two Panasonic big ones are a bit larger than the Su'scons and need some tweaking in the neighborhood for clearance.

BTW, I was puzzled when I couldn't find any 'Panasonic' marks on them, and even more puzzled when I couldn't find Panasonic in this list . Then I learnt that Panasonic was called Matsushita years ago, and that Panasonic caps are marked 'M' :

[mariushm]

Re: Cheap PSU: Piece of junk or semi-decent?

You'll find them under M, for Matsushita.

From 1935 to October 1, 2008 the company name was "Matsushita Electric Industrial Co., Ltd."[4][5]

On January 10, 2008, the company announced that it would change its name to "Panasonic Corporation", with effect from October 1, 2008 to conform with its global brand name "Panasonic".[6] The name change was approved at a shareholders' meeting on June 26, 2008 after consultation with the Matsushita family.[7]

I'm not familiar with the top logo though, the triangle looks very close to SamYoung's logo. Don't be confused.

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

... I'm not familiar with the top logo though, the triangle looks very close to SamYoung's logo. Don't be confused.

Scroll down to the bottom: http://freespace.virgin.net/matt.wai...ogos/logo2.htm

Also:

http://how-to.wikia.com/wiki/File:Ic...onics_Corp.jpg

http://www.classiccmp.org/rtellason/...ctorlogos.html

[tom66]

Re: Cheap PSU: Piece of junk or semi-decent?

Yellow Y-caps can still be real -- they don't HAVE to be cyan.

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

Are these real Y-caps?:

[Behemot]

Re: Cheap PSU: Piece of junk or semi-decent?

Average ceramics.

[tom66]

Re: Cheap PSU: Piece of junk or semi-decent?

Yeah they're fakes. Sometimes you see genuine yellow/orange y-caps.

[Behemot]

Re: Cheap PSU: Piece of junk or semi-decent?

Yeah they're fakes.

[tom66]

Re: Cheap PSU: Piece of junk or semi-decent?

Not real Y-caps.

[Behemot]

Re: Cheap PSU: Piece of junk or semi-decent?

They are not even trying to be Y caps. Just somebody put them in instead of Y caps. See all the difference?

[tom66]

Re: Cheap PSU: Piece of junk or semi-decent?

Yes, that is my point. But the fact of the matter is they are trying to substitute ordinary ceramics for y-caps. This is a safety issue.

[Behemot]

Re: Cheap PSU: Piece of junk or semi-decent?

Oh you can delete this 2

[TELVM]

Re: Cheap PSU: Piece of junk or semi-decent?

Just a disturbing thought I've had. This Allied PSU came with 200V Su'scon primary caps, worked fine for many years powering a P4 Preshott, and I'm now replacing them with 200V Panasonics.

But it's 230VAC from the wall here around. Wouldn't have been better replacing with higher voltage big caps?

What's the relationship between voltage from the wall and the primary caps' voltage?