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> Input Voltage Range Of Ea-72?, Does it work on 240V?
daniel3000
post Jun 5 2005, 01:05 PM
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Hello,

I received the 5V power adapter EA-72 with my Zaurus SL-C3000 from Japan. It only says "AC 100V 50/60Hz 11VA" as the input voltage. But these kind of adapters usually have 100-240V range. Does anyone know if it's really limited to 100V? I live in Europe and have 240V AC 50Hz. I'd like to use the adapter, but I'm a bit afraid of simply trying it 8-)

Thanks
daniel
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Stubear
post Jun 5 2005, 03:53 PM
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The EA-72 was designed for use only in Japan, so they didn't bother with anything but 100V.

DO NOT try this with 240V, it will work for a very short time before destroying your Z's charging circuit.

Stu
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TRIsoft
post Jun 6 2005, 12:04 AM
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QUOTE(Stubear @ Jun 6 2005, 12:53 AM)
DO NOT try this with 240V, it will work for a very short time before destroying your Z's charging circuit.
*

Eventually the EA-72 will explode _before_ it damages the
Zaurus smile.gif
But, serious now: The EA-72 is 100V / Japan only !
Outside Japan please use the EA-70S type 110-240V.
Powering the Zaurus with incorrect AC adaptors is the
#1 reason for damaged / destroyed Zauris. Just use the
search function of the forum or Google a bit around.
Only the EA-70S type is 100% safe to use.

///TRIsoft

Marc Stephan
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raduga
post Jun 6 2005, 09:54 AM
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QUOTE(TRIsoft @ Jun 6 2005, 12:04 AM)
Powering the Zaurus with incorrect AC adaptors is the
#1 reason for damaged / destroyed Zauris.

*


By what mechanism does the EA-72 damage / destroy Zaurus charging circuitry?
On ZUG, it's been reported anecdotally by numerous users in ZUG that after using the EA-72
for some time, their Zaurus internal charger failed; in most cases the users aren't really sure what the problem is,
and in some cases we can only speculate that it was the EA-72.

You've repeated several times that you've seen the EA-72 damage and destroy Zauruses-
but I haven't really seen any explanation of what causes it.

Is the step-down transformer outputting more than 5VDC (overvoltage)?
Is it providing less than 5VDC (undervoltage)?
Is it providing more than the specified 2A, or less than needed?

It would be nice to have some hard, clear explanation of why this device is dangerous;
anecdotal evidence, while compelling, just isn't enough.
If the EA-72 is providing correct voltage and current, then it shouldn't bother
the Zaurus.

Unless... repeated abuse of the transformer by overvolting it's input, causes the
whole adaptor to fail, and start generating output outside it's specification.

ANECDOTE: I used an EA-72 for 12 months on my SL-C760, with no observed
degradation of charger or battery. Is there cumulative (unobserved) damage
accruing in this configuration, or is it primarily at risk for catastrophic failure
after some indeterminate period of use?

Marc:

Thank you for your feedback. If you know anything else about the circumstances
of EA-72 failure, I would really like to know, so that we can set the record straight.

The back-and-forth "It will kill your Zaurus!" "It works fine for me" arguments are
not getting anyware, and serve the community less well than clear answers might.

Checking the voltage/current on good/failed/EA72/EA70 adaptors and Zauruses
should be feasible with some effort.

Thanks,

raduga
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TRIsoft
post Jun 6 2005, 12:04 PM
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Raduga,

OK, let's try to make a "compilation" of the various power-threads:
(Big post warning ! Better get some coffee !)

My guess with the "explosion" was done because Daniel said that
he's a user in Europe and here we have 220-240V AC.
The EA-72 as a 100V adaptor will definitely be destroyed if you
try to put it into a 230/240V plug.

We had reports from people using the EA-72 in Europe with a
step-down-transformer to 110V and they damaged their Zaurus.
We guess this may be caused due to a bad step-down-transformer.

I know that a lot of US users use the EA-72 at 110V and a lot
of them don't have any problems. I can't comment this, we simply
don't have that much US customers.
But the point that makes me think is : If the EA-72 works in the US,
why is SHARP selling the US units (SL-5500/5600/6000) with the
much more expensive EA-70S ?

The Zaurus really doesn't like over-/undervoltage. I can't give you
a detailed explanation why, i'm not an electronics guru.

So, using of a no-name or different AC adaptor always includes
the risk of frying the charger electronics with incorrect voltage.
Forums on the net are full of reports and we also get about 1-2
calls / emails weekly from users with these problems.

Building a stable and good AC adaptor is no rocket science, so
i really don't know _why_ there're obviously so many bad adaptors
on the market. We simply go the easy way and supply the EA-70S
for all our Zauris like SHARP does and we definitely have no user
with a fried charger from thousands of units in Europe.

The one and only unit (sold from us) we ever had with a fried
charger was damaged using our USB charging cable on a bad
active hub. So (for the C700/750/760/860) we can say that
charging over USB is safe. Unfortunately USB-charging is no
longer possible with the new models.

The "i fried my charger" problem exists since the SL-5500.
Defective chargers where >90% of all warranty issues.
Some of them fried with the EA-70S while flashing a ROM
(we never tracked down how, it was about 10-15 units) and
all other units went dead with selfmade battery packs and
3rd party AC adaptors.

Conclusion:
Do's:
You may try the EA72 if you're in the US. But i (and this is my
personal opinion) would have a bad feeling.
You may use a USB charging cable for the previous SL-C models.
You can trust the EA-70S.
For all other accessories, i would ask the supplier to give me
a written note that this one will work with my Zaurus.

Dont's:
Better never plug an adaptor on your Zaurus only because
there's "5V" written on it.
Never try a cheap car charger (MHPower from SerialIO is safe)
and start your engine while the Zaurus is plugged.
Be careful with cheap battery packs. Highend packs like the one
from Socket are reported to be safe (so was the Samsung, but
this is unfortunately discontinued).

And please think a second about the following:
You spend >$500 and maybe with accessories $800-$1000 of
your hard earned cash for your Zaurus.
So _why_ are you looking for a $5 AC adaptor ????

Maybe one of the US vendors could also add something to this
thread. I would love to see some feedback what their
experiences are.

///TRIsoft

Marc Stephan
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maslovsky
post Jun 6 2005, 12:29 PM
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I would agree with Mark. I personaly know a few people, who burned their Zaurus charging curcuts by using cheap AC and car adapter. Sometimes it's easy to fix (a friend of mine is doing that) but often Zaurus is dead permanently.

I've always been using EA-70 from my old 5500 (a version of 70S adapter with US style plug) and bought myself a couple of these. It's only $25 at amazon in the US and it's proven to be safe.

I've also been using a car adaptor from Serialo witn no problems.
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daniel3000
post Jun 6 2005, 12:42 PM
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I have bought two of these common switchable power supplies at Conrad Electronic (abt. 10 Euro) and at Saturn (20 Euro) in Germany. Switched to 4,5V they work fine with the Zaurus SL-C3000 (a volt meter indicates about 4,7-4,9V idle voltage).

I only asked about the Sharp charger because it is so incredibly small. Would be nice if I could use it, but after all these warnings, I won't. Thank you!

I can well imagine that a too high voltage damages the charging circuit. But a too low voltage is probably not dangerous. Except in one situation: If the power is not enough (i.e. voltage times current), the charging circuit may become hot and may be destroyed with time. But using my two power supplies, I have not encountered any heat, so I consider them to be safe.

This is no recommendation, since I use them for only 3-4 weeks now, only 2-3 times a week. So I don't really have long-term experience.

However, I HAD problems with a switched power supply from an USB hub, which said it has 5V on the output (I measured abt. 5.5V idle). The Zaurus could not be switched on with this thing plugged in, and it needed a battery remove and reset button press in order to come back after a while. Phew - I was a bit scared while the Zaurus was dead (well, it was rather a coma than death).

Why think twice about the price of an adapter?
Well, because I do not only need one. I use my Palmtop (and later maybe the Zaurus, once I have migrated) at different places, and I don't want to carry a power adapter with me. For my current palmtop (HP 200LX) I have 5 or 6 adapters at different places.
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daniel3000
post Jun 6 2005, 12:45 PM
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QUOTE(maslovsky @ Jun 6 2005, 10:29 PM)
I've always been using EA-70 from my old 5500 (a version of 70S adapter with US style plug) and bought myself a couple of these. It's only $25 at amazon in the US and it's proven to be safe.


Trisoft: For what price can I get a European version of that adapter? If it's not far more expensive that the one Maslovsky mentioned, I may rather use these than my two "cheap" ones.
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raduga
post Jun 6 2005, 01:15 PM
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QUOTE(TRIsoft @ Jun 6 2005, 12:04 PM)
Raduga,

OK, let's try to make a "compilation" of the various power-threads:
(Big post warning ! Better get some coffee !)

Marc Stephan
*


Thank you very much!
Its extremely helpful; I wanted to know how it was that some people
report using the EA-72 without any trouble, and that some people
report using it and have a fried Zaurus. The answer is still... uncertain smile.gif
but much clearer now.

My speculation on why Sharp sells the more expensive EA-70 in US
(assuming that the EA-72 works safely in the US... which is unproven)
is... the EA-70 is much more flexible; designed to handle a wider range
of voltages enough to handle regional or occasional deviation from US mains standards
but it also works as a single "non-Japanese" supply for all Zauruses sold abroad.

It would be far easier for Sharp to divide the market into Japan and Non-Japan
as much as possible, so they do this with the power supplies.

I would like to speculate that the EA-72 is safe to use in the US, but
there's still not enough evidence to support that speculation,
so I guess I will grudgingly have to agree with Marc, to just go out and buy
an EA-70 anyway.

much appreciated!

-raduga

p.s. my new C-1000 came from Streamline with an EA-70, so for me it's a moot point
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Streamline
post Jun 6 2005, 02:16 PM
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Hello Marc and all,
I will reply from the U.S market. Basically the way I see it is the EA-72 adapter was supplied in Japan. I really dont think Sharp would have spent the money for another adapter if the Ea-72 was fine to use in the U.S They sold the 6000 model with the Ea-70 adapter so we will provide the same adapter with these units as they did. I am not sure if its a power issue or maybe the Ea-72 doesn't pass the FCC compliance. However I really don't feel they would make another adapter if they didn't have to.
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gdog
post Jun 6 2005, 09:21 PM
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QUOTE(TRIsoft @ Jun 6 2005, 08:04 PM)
Raduga,

OK, let's try to make a "compilation" of the various power-threads:
(Big post warning ! Better get some coffee !)

If the EA-72 works in the US, why is SHARP selling the US units (SL-5500/5600/6000) with the much more expensive EA-70S ?...


Perhaps because Sharp is NOT selling the CxK line in the US and therefore they do not need to worry about 110-120V supplies coming into the EA-72, and therefore don't need to bundle a more expensive adapter? Actually in rereading your statement and my answer I didn't answer the question. We can disregard this answer though it may have just been safety (and/or less risk of RMAs).

QUOTE
...
The Zaurus really doesn't like over-/undervoltage. I can't give you
a detailed explanation why, i'm not an electronics guru.
...


No electronic circuitry likes less or more power than it was designed for. In fact too little can be just as hazardess as too much! But most are built to withstand a wider range than documented. More on that below.


QUOTE
...
We simply go the easy way and supply the EA-70S
for all our Zauris like SHARP does and we definitely have no user
with a fried charger from thousands of units in Europe.
...
The "i fried my charger" problem exists since the SL-5500.
Defective chargers where >90% of all warranty issues.
Some of them fried with the EA-70S while flashing a ROM
(we never tracked down how, it was about 10-15 units) and
all other units went dead with selfmade battery packs and
3rd party AC adaptors.

Conclusion:
Do's:
You may try the EA72 if you're in the US. But i (and this is my
personal opinion) would have a bad feeling.
You may use a USB charging cable for the previous SL-C models.
You can trust the EA-70S.
For all other accessories, i would ask the supplier to give me
a written note that this one will work with my Zaurus.
...

///TRIsoft

Marc Stephan
*


Marc,

I applaud you for going the safe and conscientious route and offeriing the EA-72 for USA use!

I seriously hope the EA-72 continues to power and charge my C1K here in the USA with no damage, at least to the Z, as will as the additional EA-72 that I just ordered from one of your competitors (who by the way did not even offer the EA-70 as an optional accessory.)

One thing that could be a major factor in the situation where some USA users have problems and some don't is the use of surge protectors between the wall and the EA-72. While most circuitry in expensive equipment is built to handle a certain decrease or increase in its rated input voltage and amperage, a surge protector could be the difference between the EA-72 being able to handle as much as 120V but no more. Without a surge protector it is not uncommon to get 130V out of your wall socket as a spike. And at 130V the EA-72 just may not be built to handle what would then be a 30% increase in its rated input voltage. I know this is conjecture, and anecdotal but it does make sense.

Just my $.02

Regards,

gdog
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gdog
post Jun 10 2005, 02:59 PM
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Oddly enough I may be a victim of the EA-72 problem even though I always use a surge protector.

I was using my C1K last night on battery, and although I hadn't charged it in a while due to only occasional use, the battery indicator still showed about 75% charge. Well it suddenly just died and refused to come on unless I plugged the adapter in. So I did so and finished my work, then this morning I charged it without using it until the charging light went off. I then unplugged the adapter and turned it on. It came on for just a moment and it then turned itself off. I seem to be unable to use it without the adaptor at this point.

Are those the symptoms of the dreaded EA-72 problems that others have experienced?

Regards,

gdog
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