Dodgy step down tranny

[keithr]

**The mass SHOULD be a giveaway. However, I've worked on more equipment than
I care to think about, where the manufacturer (usually Chinese) has
incorporated large pieces of non-structural steel to increase the mass of
the product. I've even seen all-aluminum chassis devices, where steel has
been used to increase mass. The first time I saw this done, was with an
Onkyo (Japanese) CD player, back in the 1990s. The CD player weighed in at a
hefty 25-odd kg. More than half that mass was the result of a large piece of
steel bolted to the base plate. Without opening the player, an owner would
never realise that it was the reason for all that mass.

Mild steel plate is still less expensive than copper and laminated iron (in
the shape of a transformer).

I suppose that they could claim it to be a vibration damper. Stranger
things have been know with "HiFi" devices.

 

[Sylvia Else]

Also, certain products might have to "feel to be a certain weight" in
relation to its physical volume, for the consumer to perceive them to
be a "quality" product.

You would know more about it than I would - being in the industry -
but I think high end audio would fall into this category ?

Still, 25kg?

Any consumer who expects a CD player to weigh that much fully deserves
the hernia they get when trying to install it.

Sylvia.

 

[Phil Allison]

"Stupider than anyone Else on Earth"

Your point being?

** Jesus fucking Christ !!

It ain't on sale right now - but maybe hundreds are out there.

It's a nice example of eBay fraud too.

Beware.


..... Phil

 

[Sylvia Else]

"Stupider than anyone Else on Earth"


** Jesus fucking Christ !!

It ain't on sale right now - but maybe hundreds are out there.

OK, so what are you doing about it besides winge on aus.electronics?

Have you contacted the supplier? The Department of Fair Trading? Maybe
there should be a product recall.

It's a nice example of eBay fraud too.

It may have been. It may not. Depends how it was described *on eBay* at
the time.

Sylvia.

 

[Sylvia Else]

The average consumer would not know what weight to expect.

I agree. The point I was making is that it would make little sense for
the website to be overstating the weight, because the only people who
would pay attention to it for the purpose of assessing power rating
would also notice immediately that what they received was too light.

They also would not
know there was a problem until they tried to run it at full load, and
found that they had
an appliance not working effectively.


There is also the issue of mains frequency, especially with
transformers, ballasts etc that are made for 60hz.
Induction motors would also run slowly.

Certainly that's something the user has to be aware of, but the web site
makes no representation that the frequency is changed.

Sylvia.

 

[Phil Allison]

"Stupider than anyone Else on Earth"

OK, so what are you doing about it besides winge

** No whinging for me - the POS is not mine.

I am publishing simple a " heads up".

For interest sake.

Have you contacted the supplier? The Department of Fair Trading? Maybe
there should be a product recall.

** I cannot see there is a major safety issue - once the tranny begins to
burn, the 10 amp fuse will blow.

But any purchasers who have one burn out like this are entitled to a
refund.

It may have been. It may not.

** FUCKING bollocks.


..... Phil

 

[Tony the Abbott]

Yes, you're right, I had a brain spasm. Just as well you've never
made a mistake.

Nothing to worry about Sylvia , "Shit happens" to the best of us!

 

[Sylvia Else]

Nothing to worry about Sylvia , "Shit happens" to the best of us!

Sadly true, though given the fuss that's being made about your
namesake's comment, some people don't seem to understand that.

Sylvia.

 

[Chas]

"kreed"

Interesting too how the 3kw version seems to have (hard to read) a
32amp breaker on the front panel.
Unless they are fusing the secondary with it.

**Bound to be in the secondary.

The unit I have here has the fuse fitted in the primary cos at 18 amps
nominal - the secondary side would need a fuse and fuse holder bigger
than is cheaply available.

The toroidal auto-tranny inside looks roughly made and carries no
labelling at al.

Dimensions are 120mm dia and 75mm high.

There are just three light gauge, flexible wires coming out.


.... Phil

Three wires indeed makes it an autotransformer. In my copy of AS3000,
section 4.28.4 (Autotransformers) clause 2 states: "Prohibited use.
Autotransformers shall not be used for reducing or controlling the voltage
to equipment which is liable to be handled in normal use."

Seems like the amp you are trying to repair is part of an all too common
illegal setup; be careful Phil.
--
Regards,

Chas.

(To email me, replace "xxx" with letters tango papa golf.)

 

[Phil Allison]

"Chas"

"Phil Allison"
Three wires indeed makes it an autotransformer. In my copy of AS3000,
section 4.28.4 (Autotransformers) clause 2 states: "Prohibited use.
Autotransformers shall not be used for reducing or controlling the voltage
to equipment which is liable to be handled in normal use."

** Yep - I know that section of AS3000 very well !!!!

But AS3000 is the "electrical wiring rules" - ie the electrician's bible.

4.28.4 prohibits the * INSTALLATION * of a step down, auto-transformer for
use with portable appliances.

(IIRC, ones that convert 240v to 220v are excepted from the prohibition )

AS3000 is NOT relevant to plug-in appliances sold to the public.

Seems like the amp you are trying to repair is part of an all too common
illegal setup; be careful Phil.

** Nothing illegal about it in Australia, at present.

I have personally campaigned against the open sale of auto-transformer 240V
/120 V step-downs for many years. There was a Forum column about the topic
in EA magazine in the mid 1990s that was due to my efforts.

I pointed out some of the dangers inherent in the use of such transformers
with old, US made appliances like valve radios and guitar amplifiers -
which are now pouring into this country, courtesy mostly of eBay sales.

I believe I was largely responsible for getting Jaycar to drop all but one
of the units they were selling, getting Arlec to stop importing them and
getting Farnell to drop the Arlec brand one they were selling. Unfortunately
eBay sellers appear to be a law unto themselves - even the ones operating
in this country.

It will probably take at least a couple of fatal accidents before Government
authorities step in and ban them completely.

Even that will be far too late - as there are currently many thousands in
circulation.


...... Phil

 

[Phil Allison]

"kreed"

** At 12.5 kg including box and assuming there is a toroidal tranny inside,
the unit must be an isolation type.



...... Phil

 

[Sylvia Else]

"kreed"


** At 12.5 kg including box and assuming there is a toroidal tranny inside,
the unit must be an isolation type.

However, I noted that their 1kW version weighs quite a lot less than the
1kW isolating step-down transformer from Jaycar.

On the eBay web site the supplier has two 500W step down transformers.
On is an isolating transformer, the other is not. The isolating
transformer weighs 12kg, the non-isolating version only 3.4kg. Since
they've expressly identified one transformer as isolating, but none of
their other transformers that way, it seems reasonably safe to assume
that the others are autotransformers.

Sylvia.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

However, I noted that their 1kW version weighs quite a lot less than the
1kW isolating step-down transformer from Jaycar.

** The Jaycar one is obviously an E-Core type - see the pic ??

An E-core will be up to double the weight of a comparable toroidal type.

An auto-transformer will be around half the weight of a comparable isolation
type.



..... Phil

 

[Ross Herbert]

Then it's not the same as the 2kW version on the website, which weighs
12.5 kg. Indeed, it has a similar weight to the 500W version.

Perhaps there's a QA problem with labelling.

Sylvia.

Even at 12.5kg I doubt the 2kW rating is genuine. I have a 1kW rated
isolation transformer which weighs in at over 16kg - and that isn't in a
case. Admittedly, mine is not a toroidal but the variation in weight for a
supposed 2kW toroidal versus a 1kw E-I tranny is still an indication of lack
of truthfulness in the rating for this tranny.

 

[Phil Allison]

"Ross Herbert"

Even at 12.5kg I doubt the 2kW rating is genuine.

** A 2kVA toroidal *auto-transformer * uses the same core size as a 1300 VA
isolation type.

Makes the weight around 11kg plus box.

The stupid thing is the 110 volt rating - which suits neither the US or
Japan.

And if they deliver only 100 volts or so ON LOAD - like the one I have
ere - they are suitable for Japanese local market gear only.

The valve amplifier that came with that " dodgy step down " loses 40% of its
normal output power when used this way.


...... Phil

 

[Bruce Cook]

On 9/02/2011 12:55 PM, Trevor Wilson wrote: [...]

**The mass SHOULD be a giveaway. However, I've worked on more equipment
than I care to think about, where the manufacturer (usually Chinese) has
incorporated large pieces of non-structural steel to increase the mass of
the product. I've even seen all-aluminum chassis devices, where steel has
been used to increase mass. The first time I saw this done, was with an
Onkyo (Japanese) CD player, back in the 1990s. The CD player weighed in
at a hefty 25-odd kg. More than half that mass was the result of a large
piece of steel bolted to the base plate. Without opening the player, an
owner would never realise that it was the reason for all that mass.

Seems an odd thing to do with a CD player, given that I wouldn't have
thought a consumer would expect it to be particularly heavy - and
certainly not 25kg heavy.

Early CD players had sprung feet and a large ballast to damp vibrations. As
electronics got better & tracking became more reliable the manufacturers did
away with it.

I have an early Kenwood player here built that way. I wonder if it was a
case of the high end auto manufacturers translating their experience with
turntables into the new fangled CD players.

Bruce

 

[Phil Allison]

"Bruce Kook"

Early CD players had sprung feet and a large ballast to damp vibrations.

** Only a tiny few models had any such nonsense.

As electronics got better & tracking became more reliable the
manufacturers did
away with it.

** Horse manure.

I have an early Kenwood player here built that way. I wonder if it was a
case of the high end auto manufacturers translating their experience with
turntables into the new fangled CD players.

** Pure marketing hype.




...... Phil