Sloppy china practices (example)

[[email protected]]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

 

[martin griffith]

On 12 Jul 2007 15:59:14 GMT, in sci.electronics.design

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

how about
http://es.geocities.com/mart_in_medina/warninglabel1.jpg


martin

 

[Miguel Gimenez]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

I got a free chinese NiMH charger with a camera, it charged only
partially the batteries and I opened it, looking for the controller chip
and the algorithm used. You can see the inside here (there were no
components in the other side):

http://www.solener.com/Charger.jpg

 

[Joel Kolstad]

Comments?

Well... the Chinese *can* build to whatever quality level you're willing to
pay for. Many Chinese *designs* are junk because they know, in many cases,
consumers are ignorant: Many computer "enthusiast" "think" they need a, say,
500W power supply when they really only need a solid 250W device. If you toss
truth-in-marketing out the window, clearly it's a win to advertise a 250W
power supply at 500W to give yourself a competitive edge, right?

 

[Nico Coesel]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps

I think you looked wrong. IIRC the 5400 series are 50Hz AC rectifiers
and therefore too slow to act as a rectifier diode in a switch mode
power supply.

 

[[email protected]]

Well... the Chinese *can* build to whatever quality level you're willing to
pay for. Many Chinese *designs* are junk because they know, in many cases,
consumers are ignorant: Many computer "enthusiast" "think" they need a, say,
500W power supply when they really only need a solid 250W device. If you toss
truth-in-marketing out the window, clearly it's a win to advertise a 250W
power supply at 500W to give yourself a competitive edge, right?

Sure, it will also tell us that chinese goods have way higher probability
of unreliability. And in the event of a construction that requires that
components are to specification, may give a new meaning to "chinese fireworks".

 

[[email protected]]

On 12 Jul 2007 15:59:14 GMT, in sci.electronics.design
[email protected] wrote:
how about
http://es.geocities.com/mart_in_medina/warninglabel1.jpg

I like it

(considering what I have seen so far)

 

[Eeyore]

I think you looked wrong. IIRC the 5400 series are 50Hz AC rectifiers
and therefore too slow to act as a rectifier diode in a switch mode
power supply.

The rectifier for the 5V in such a PSU is normally a 3 lead TO-220 type.

I'd say the author may not be terribly competent e.g.

"These supplies use a 30 amp diode which supplies both the 5 volt rail and the 12
volt rail." is clear nonsense.

Graham

 

[Eeyore]

Sure, it will also tell us that chinese goods have way higher probability
of unreliability. And in the event of a construction that requires that
components are to specification, may give a new meaning to "chinese fireworks".

You have consumer protection legislation in Sweden.

Graham

 

[GregS]

Sure, it will also tell us that chinese goods have way higher probability
of unreliability. And in the event of a construction that requires that
components are to specification, may give a new meaning to "chinese fireworks".

In watching this video, I never thought it could be like this. Makes American factories
seem, well there are no American factories.


http://www.gearwire.com/behringerfactory-videodiary-chrisholder.html

 

[[email protected]]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

I sort of question why modify a SMPS if for the the same money you can
buy one with 25 A total on 12V?
I have a big CB transmitter (150W pep) and it has same output at 11.8
as 13.8 V.
Only display backlight dims a bit....
Some of those supplies have 12V 14A and 12V 15A for example, outputs
that possibly can be used in parallel.
Some time ago I checked almost a hundred of those PC power supplies
just for my transmitter.
Some can simply do 12V 25A.

I ended up running the thing from a sealed lead-acid that is
constantly under charge to reduce hum and ground loops (audio is via
the PC).

 

[[email protected]]

You have consumer protection legislation in Sweden.

Yep, but that won't protect any direct import. Or importer in Sweden not
checking the quality. There have been few 'oops' that even hit national news.

 

[JeffM]

http://es.geocities.com/mart_in_medina/warninglabel1.jpg

ISTM the bomb should have a strikethru
or the "DOES NOT CONTAIN" should be "CONTAINS".
....or am I missing something?

 

[martin griffith]

ISTM the bomb should have a strikethru
or the "DOES NOT CONTAIN" should be "CONTAINS".
...or am I missing something?

I couldn't immediately think of a suitable icon
I did it very quickly, just as an idea,

just a random idea


martin

 

[Joel Kolstad]

Sure, it will also tell us that chinese goods have way higher probability
of unreliability.

Given that probably >90% of all consumer electronics comes from China these
days, that would be the case even if they didn't engage in crappy
engineering/specsmanship.

And in the event of a construction that requires that
components are to specification, may give a new meaning to "chinese
fireworks".

Very true... anyone who actually cares about their specs needs to test them
themselves, or at least try to find some test documentation from a lab they
trust.

 

[[email protected]]

Ie the chinese manufactor did:

how about
http://es.geocities.com/mart_in_medina/warninglabel1.jpg

"Free of china manufactured components" ..?

Kind of like the "Intel inside" (or "Intel free"

(Maybe a bit rude, bit until the gov in .ch deals with it..)

 

[D from BC]

I got a free chinese NiMH charger with a camera, it charged only
partially the batteries and I opened it, looking for the controller chip
and the algorithm used. You can see the inside here (there were no
components in the other side):

http://www.solener.com/Charger.jpg

It's a battery cooker?
D from BC

 

[John Larkin]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

I evaluated a name-brand Japanese switching supply against the
MeanWell chinese equivalent. The MW was better. 48 volts, 150 watts,
open frame, $42.

John

 

[Spehro Pefhany]

I evaluated a name-brand Japanese switching supply against the
MeanWell chinese equivalent. The MW was better. 48 volts, 150 watts,
open frame, $42.

John

What a terrible name though. Kind of like this one:
http://www.sure-fire.com.tw/

I have an NiMH battery charger (made in China by or for a Taiwan-based
company). It's beautiful.. separate switchers for each cell as well as
the off-line switcher. Light, small, and it was cheap to buy in a
Taipei shop. If you buy the cheapest electronics at the cheapest place
(or the cheapest tools) you're likely going to find problems. There
are seemingly legitimate Chinese companies like the 2000+ employee
company that was spamming us here a while ago who put fake UL markings
on their products. Buyer beware, but most of the stuff is quite good
these days and getting better and better every year as they get the
latest production equipment. OTOH, there are fast buck artists and
they have an alarming tendency to try and compete each other into the
ground, which is not necessarily good for buyers and end customers.


Best regards,
Spehro Pefhany

 

[[email protected]]

http://www.users.on.net/~endsodds/smps.htm

"I opened up a whole bunch of SMPS (around 12) from different manufacturers
and carefully examined them. The worst power supply was a Chinese made brand
which advertised a 250 watt rating together with 5 volts at 25 amps on the
cover plate but on examination used 1N5404s in the 5 volt supply line (3 amps
max.) and completely deleted all input and output RF filtering components. As
the quality moved slowly upward from the this extraordinary low, each of the
supplies had various serious shortcomings except.."

Ie the chinese manufactor did:
* Rate at 25A - But used 3A diodes.
* No RF filter on input & output.

Comments?

Made in China, but with Japanese ass kicking.
http://www.seasonicusa.com