piezotransformer/piezoceramic transformer driver

M

Mebart

Guest
I've been interested in piezotransformers for some time now. Despite
the fact that they have been around for awhile, not many electronics
people seem to be familiar with them.

Currently, they are used to generate high voltage for ion air
purifiers (ozone), that are supposed to make the air safer to breathe.
Interestingly enough, these products aren't sold by reputable sellers
and they all come in plain boxes with no mention of the point of
origin. So, getting information about how they operate is easier said
than done:>:

They are also widely used as CCFL power sources, where the
requirements are ~600 VAC at 2 to 6 ma.

They excel at producing high voltage with resistive loads greater than
150 K ohms and up. In fact, they have so much voltage gain when the
load impedance is high, that they must be throttled back in order to
prevent the output voltage from arcing through the ceramic and
shattering them into pieces. Most will produce 2 kilovolts safely
however.

Anyway, I was curious whether anyone else knows about these units
and/or has designed drivers that work in constant voltage mode rather
than constant current (as the TI driver does). The specs for the TI
driver can be found at:

http://focus.ti.com/docs/prod/folders/print/ucc3977.html

The spec sheet has a very nice summary of the piezotransformer
operation in addition to chip specs.

The only US vendor that I know of (with standard products listed
online) is:

http://www.steminc.com/piezo/single_layer_transf.asp

They make multilayer and single layer piezotransformers.

CTS Ceramics claims to make them, but their website has no references
to actual part numbers of standard products.

Texas Instruments makes an evaluation kit, complete with
piezotransformers and driver chip, but it is not advertised on their
website. You have to ask specifically for it. The TI part number for
the evaluation kit (EVM) is UCC3976-77EVM. I have a pdf of the
technical info in the EVM and will send it to anyone who needs it.
I've also posted it in abse.

What say, anyone out there played with them?

Mebart
 
Mebart wrote:
Currently, they are used to generate high voltage for ion air
purifiers (ozone), that are supposed to make the air safer to breathe.
Interestingly enough, these products aren't sold by reputable sellers
and they all come in plain boxes with no mention of the point of
origin. So, getting information about how they operate is easier said
than done:>:
Click to expand...
FYI: Any "purifier" that uses ionization generates Ozone. Ozone is bad
stuff to breathe in any appreciable concentration and is _extremely_ bad
for anyone with asthma. There have been law suits and FDA actions
against sellers in the US. Guess why they are all in plain boxes with
no ID.

Not to say there is anything wrong with piezo transformers, just the
missuse of them.

Ted
 
On Tue, 03 May 2005 20:37:17 +0000, Ted Edwards wrote:

Mebart wrote:
Currently, they are used to generate high voltage for ion air
purifiers (ozone), that are supposed to make the air safer to breathe.
Interestingly enough, these products aren't sold by reputable sellers
and they all come in plain boxes with no mention of the point of
origin. So, getting information about how they operate is easier said
than done:>:

FYI: Any "purifier" that uses ionization generates Ozone. Ozone is bad
stuff to breathe in any appreciable concentration and is _extremely_ bad
for anyone with asthma. There have been law suits and FDA actions
against sellers in the US. Guess why they are all in plain boxes with
no ID.
Click to expand...
But in the "right" concentration, it makes the air smell like a forest
clearing after a spring rain. I've actually experienced that. One time I
was working with some guy who sold germicidal stuff. One customer was
an "organic" bakery that sprouted their grain before they ground it up
and baked bread with it. And they used no preservatives. It was some kind
of Biblical mandate.

Hmm - they're still there: http://www.food-for-life.com/index.asp

And their bread had a shelf life of about a day. And the bakery smelled
just like you'd expect a place to smell where they have five or 6 25,000
gallon tanks of water where they leave grain until it sprouts. IOW, lots
and lots of fungus. Well, one thing "we" did was install short-wave
(germicidal) UV lamps near the ceilings, to get the spores and crap out of
the air. Sold them a lot of biocidal cleaning crap, too - but the notable
thing was, a couple of weeks after installing the UV lights - part of
whose purpose was to cause ozone - I walked into the factory and instead
of stinking of rot, it smelled almost like fresh air. So it _does_ work,
but, as has been noted, you have to watch the concentration - it'll also
bleach the paint off the walls.
Not to say there is anything wrong with piezo transformers, just the
missuse of them.

Ted
Click to expand...
 
<Mebart> wrote in message
news:smte71hsr6g0iivi0iheaol9u9fkideugb@4ax.com...
I've been interested in piezotransformers for some time now. Despite
the fact that they have been around for awhile, not many electronics
people seem to be familiar with them.

Currently, they are used to generate high voltage for ion air
purifiers (ozone), that are supposed to make the air safer to breathe.
Interestingly enough, these products aren't sold by reputable sellers
and they all come in plain boxes with no mention of the point of
origin. So, getting information about how they operate is easier said
than done:>:

They are also widely used as CCFL power sources, where the
requirements are ~600 VAC at 2 to 6 ma.

They excel at producing high voltage with resistive loads greater than
150 K ohms and up.
Click to expand...
He must come from the department of redundancy department.

[snip]

> Mebart
 
"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2005.05.04.02.21.14.681648@example.net...
On Tue, 03 May 2005 20:37:17 +0000, Ted Edwards wrote:

Mebart wrote:
Currently, they are used to generate high voltage for ion air
purifiers (ozone), that are supposed to make the air safer to breathe.
Interestingly enough, these products aren't sold by reputable sellers
and they all come in plain boxes with no mention of the point of
origin. So, getting information about how they operate is easier said
than done:>:

FYI: Any "purifier" that uses ionization generates Ozone. Ozone is bad
stuff to breathe in any appreciable concentration and is _extremely_ bad
for anyone with asthma. There have been law suits and FDA actions
against sellers in the US. Guess why they are all in plain boxes with
no ID.

But in the "right" concentration, it makes the air smell like a forest
clearing after a spring rain. I've actually experienced that. One time I
was working with some guy who sold germicidal stuff. One customer was
an "organic" bakery that sprouted their grain before they ground it up
and baked bread with it. And they used no preservatives. It was some kind
of Biblical mandate.

Hmm - they're still there: http://www.food-for-life.com/index.asp

And their bread had a shelf life of about a day. And the bakery smelled
just like you'd expect a place to smell where they have five or 6 25,000
gallon tanks of water where they leave grain until it sprouts. IOW, lots
and lots of fungus. Well, one thing "we" did was install short-wave
(germicidal) UV lamps near the ceilings, to get the spores and crap out of
the air. Sold them a lot of biocidal cleaning crap, too - but the notable
thing was, a couple of weeks after installing the UV lights - part of
whose purpose was to cause ozone - I walked into the factory and instead
of stinking of rot, it smelled almost like fresh air. So it _does_ work,
but, as has been noted, you have to watch the concentration - it'll also
bleach the paint off the walls.

Not to say there is anything wrong with piezo transformers, just the
missuse of them.

Ted
Click to expand...
Ozone can also be used to get rid of bad smells, In my highschool days I
worked part time as a cleaner, we had a Caddy that the owner expired in, and
wasn't found for a few weeks in July. After the remains were removed we got
the car to clean it, after steam cleaning everything in the car, it still
smelt bad. We got our trust ozone genny and put it in the car for a day.

The new car smell came back.
Pat
 
On Wed, 04 May 2005 08:06:45 -0400, Pat Ford wrote:

We got our trust ozone genny and put it in the car for a day.

The new car smell came back.
Click to expand...
And six months later all the plastic bits disintegrated?

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
(Stephen Leacock)
 
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