2200uF 60V tantalum capacitors

[legg]

One of the last stumbling blocks in getting simpler power supplies to
operate over a wide environmental range, is the capacitors.

Using tantalums gets predictable performance.

There are not too many places where the application pays - designers
tend to work their way around the problem, using other methods.

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

RL

 

[Tim Williams]

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

Wow, that's a neat bit of black box...

Too bad tantalums are notorious for making messes...

Tim

 

[mike]

One of the last stumbling blocks in getting simpler power supplies to
operate over a wide environmental range, is the capacitors.

Using tantalums gets predictable performance.

There are not too many places where the application pays - designers
tend to work their way around the problem, using other methods.

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

RL

Those must be HEAVY if it costs $40 to ship 'em. )-:
mike

--
Return address is VALID.
Wanted, Slot 1 Motherboard
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http://nm7u.tripod.com/homepage/te.html
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[c a l a n d e]

Those must be HEAVY if it costs $40 to ship 'em. )-:
mike

I'd say heavy case of fee avoidance. The seller listed the weight at
"8.7oz (246grams) each."

 

[legg]

Wow, that's a neat bit of black box...

Too bad tantalums are notorious for making messes...

I think the 'notorious' problems involved either non-hermetically
sealed parts, copper casings, or oversress / reverse stress of solid
types.

These ain't broke, but obviously could be killed if the user tried
hard enough,

RL

 

[legg]

I'd say heavy case of fee avoidance. The seller listed the weight at
"8.7oz (246grams) each."

Actually, as the seller, I can say it was just a precaution. The price
of shipping can get that high for insured priority post to many
places. The bidder will be charged for cost of the actual postage
fees.

I guess this could have been made more explicit.

RL

 

[mike]

Actually, as the seller, I can say it was just a precaution. The price
of shipping can get that high for insured priority post to many
places. The bidder will be charged for cost of the actual postage
fees.

I guess this could have been made more explicit.

RL

We can't tell what you meant. I'd expect to be bound by the
actual written terms of the auction.

There's a general trend toward INFLATED shipping charges on EBAY. I
suspect that fee avoidance is a part of it. Some openly admit to
padding their profit. Some buyers seem to lose sight of the total cost
and just bid the price up anyway, so it works.

A shipping charge >3X what might be considered reasonable and 40X the
opening bid is a RED flag. Deception in one area is a good indicator of
deception in other areas.

I have no information either way about this poster; just speaking generally.

While I'm on the soapbox...
There's also another interesting trend. Outright lying about the
product, either by comission or omission. Let the auction end then
disclose the problem. Buyers seem to just pay the inflated price
anyway. Most of what I've been involved with has to do with
missing or broken "accessory items" that are absolutely necessary to get
it to work.
I get annoyed when I lose the opportunity to buy a junker
at a junker price.

I long for the good old days when (most) people were less likely to try
to sneak one by you.

mike


--
Return address is VALID.
Wanted, Slot 1 Motherboard
500MHz Tek DSOscilloscope TDS540 Make Offer
http://nm7u.tripod.com/homepage/te.html
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[Chris Morriss]

One of the last stumbling blocks in getting simpler power supplies to
operate over a wide environmental range, is the capacitors.

Using tantalums gets predictable performance.

There are not too many places where the application pays - designers
tend to work their way around the problem, using other methods.

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

RL

2200uf Tantalums? Are you serious?

 

[legg]

There's a general trend toward INFLATED shipping charges on EBAY. I
suspect that fee avoidance is a part of it. Some openly admit to
padding their profit. Some buyers seem to lose sight of the total cost
and just bid the price up anyway, so it works.

A shipping charge >3X what might be considered reasonable and 40X the
opening bid is a RED flag. Deception in one area is a good indicator of
deception in other areas.

I have no information either way about this poster; just speaking generally.

The format provided by e-bay makes it difficult to enter an advert
without filling in a 'fixed' shiping cost, if origin is non-US. I
suppose there are ways to smooth it out, but I have no experience with
the format.

My research for insured, registered postal service to Australia gave
me a Cdn$80 figure; to UK it was Cdn$50. Obviously a customer would
likely choose a slower verion, at reduced expense, if he had some
confidence in the supplier and was in no great rush. Shipping to US is
likely less, but quoting a low 'fixed' rate could obviously create
problems for the supplier.

I personally prefer standard surface parcel post, which is quite
inexpensive, when purchasing. Strangely, some suppliers won't do it
that way.

While I'm on the soapbox...
There's also another interesting trend. Outright lying about the
product, either by comission or omission. Let the auction end then
disclose the problem. Buyers seem to just pay the inflated price
anyway. Most of what I've been involved with has to do with
missing or broken "accessory items" that are absolutely necessary to get
it to work.
I get annoyed when I lose the opportunity to buy a junker
at a junker price.

Though I haven't bought through e-bay for some years, I've always been
suspicious when bid limits were reached but not exceeded - suggesting
that someone had a method to probe your limit and get you to pay it,
without exposing themselves to the same risk.

It's easier to figure out how a last minute bid can beat you by a
piddling amount - just takes a well-synchronized clock.

Generally it's too expensive to buy junk this way - but lack of other
opportunities, andsome luck can nudge ebay's usefulness upwards, for
many.

RL

 

[legg]

2200uf Tantalums? Are you serious?

You bet.

RL

 

[François Yves Le Gal]

I personally prefer standard surface parcel post, which is quite
inexpensive, when purchasing. Strangely, some suppliers won't do it
that way.

Surface mail can't usually be registered, tracked or insured, and quite a
number of packages are "lost" in the various PO systems.

 

[Gregg]

Behold, legg signalled from keyed 4-1000A filament:

I think the 'notorious' problems involved either non-hermetically sealed
parts, copper casings, or oversress / reverse stress of solid types.

These ain't broke, but obviously could be killed if the user tried hard
enough,

RL

Like:

2,200uF @ 60V? I thought you said 60uF @ 2,200V ;-)))))))

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

One of the last stumbling blocks in getting simpler power supplies to
operate over a wide environmental range, is the capacitors.

Using tantalums gets predictable performance.

There are not too many places where the application pays - designers
tend to work their way around the problem, using other methods.

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

With outrageously expensive shipping, too - $40.00. No one would want
to pay more than a few dollars for those, considering.

 

[Watson A.Name - \Watt Sun, the Dark Remover\]

[snip]

We can't tell what you meant. I'd expect to be bound by the
actual written terms of the auction.

There's a general trend toward INFLATED shipping charges on EBAY. I
suspect that fee avoidance is a part of it. Some openly admit to
padding their profit. Some buyers seem to lose sight of the total cost
and just bid the price up anyway, so it works.

A shipping charge >3X what might be considered reasonable and 40X the
opening bid is a RED flag. Deception in one area is a good indicator of
deception in other areas.

I agree. I've now seen many auctions that do exactly this: start at a
dollar with S&H fees of many times the starting fee, just to 'make sure'
the seller will not lose money.

I have no information either way about this poster; just speaking generally.

While I'm on the soapbox...

Right. That's why it's often called Sleaze Bay. Here's a very good
article on it. http://www.forbes.com/asap/2000/1127/134.html

 

[Al]

I think the 'notorious' problems involved either non-hermetically
sealed parts, copper casings, or oversress / reverse stress of solid
types.

These ain't broke, but obviously could be killed if the user tried
hard enough,

RL

Cheap tantalums do have reliability problems. I have worked in failure
analysis on military electronics for over 30 years and can tell you that
the number of electrically defective tantalums that I have come upon can
be counted on the fingers of one hand. And most of those were the ones
which used sulfuric acid as the electrolyte. A qualified production
line, burn-in and testing will insure trouble free operation for many
years.

Al

 

[legg]

Cheap tantalums do have reliability problems. I have worked in failure
analysis on military electronics for over 30 years and can tell you that
the number of electrically defective tantalums that I have come upon can
be counted on the fingers of one hand. And most of those were the ones
which used sulfuric acid as the electrolyte. A qualified production
line, burn-in and testing will insure trouble free operation for many
years.

The switch to silver casings and hermetic glass-to-metal seals
addressed the problem with the electrolyte used in wet tantalums. The
later use of tantalum casings was apparently a belt-plus-braces
solution - the improved part types needed requalification, anyways, so
why not.......

All the wet ones I've seen fail, used rubber/plastic/epoxy types of
seals, or plated copper casings.

I inspected the guts of one assembly, in order to get a better idea of
what kind of aminal was being dealt with. No sign of corrosion,
oxidation, pitting, fatigue or leakage anywhere. It was a pain, but it
had to be done before their usefulness could be established to any
extent. Testing only tells you so much about a black box.

RL

 

[legg]

One of the last stumbling blocks in getting simpler power supplies to
operate over a wide environmental range, is the capacitors.

Using tantalums gets predictable performance.

There are not too many places where the application pays - designers
tend to work their way around the problem, using other methods.

Others may have other ideas where to stick them.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3861637697

Well, for whatever the reasons, it seems there are no bidders for such
critters.

http://makeashorterlink.com/?C41956A1A


RL

 

[Dwaine Garden]

The format provided by e-bay makes it difficult to enter an advert
without filling in a 'fixed' shiping cost, if origin is non-US. I
suppose there are ways to smooth it out, but I have no experience with
the format.

My research for insured, registered postal service to Australia gave
me a Cdn$80 figure; to UK it was Cdn$50. Obviously a customer would
likely choose a slower verion, at reduced expense, if he had some
confidence in the supplier and was in no great rush. Shipping to US is
likely less, but quoting a low 'fixed' rate could obviously create
problems for the supplier.

I personally prefer standard surface parcel post, which is quite
inexpensive, when purchasing. Strangely, some suppliers won't do it
that way.




Though I haven't bought through e-bay for some years, I've always been
suspicious when bid limits were reached but not exceeded - suggesting
that someone had a method to probe your limit and get you to pay it,
without exposing themselves to the same risk.

It's easier to figure out how a last minute bid can beat you by a
piddling amount - just takes a well-synchronized clock.

Generally it's too expensive to buy junk this way - but lack of other
opportunities, andsome luck can nudge ebay's usefulness upwards, for
many.

RL

I found my Dynaco ST70 on ebay for $102.00. It was a great find.

Dwaine.

 

[James Meyer]

I found my Dynaco ST70 on ebay for $102.00. It was a great find.

Dwaine.

I found my ST70 in a pile of old, used, lab equipment in the hallway of
the university where I worked. It was waiting to be taken to the dump. I gave
it a new home for the price of picking it up.

Jim