Maker Pro
Maker Pro

new models of personal air purifiers

M

Mebart

Jan 1, 1970
0
I'm curious whether anyone has dissected any of the latest version of
personal air purifiers? They are also sold as usb port plug ins to
purify the air near your computer...and, still others are sold to
purify the air in your car. They are sometimes called negative ion
generators and the sellers claim that breathing the ozone they produce
is supposed to improve your health:>: They usually include 'piezo' in
the title of the product.

"Piezo" comes from the method used to produce high voltage, which
produces the ozone (or negative ions as the sellers like to put it).
Piezo technology means piezotransformer or piezoelectric transformer
or piezo transformer, they go by a few different names. I'm fascinated
by these devices and want to learn more, especially regarding the
drivers.

I was wondering whether anyone had taken any of these units apart or
whether there are any websites dedicated to sharing information about
these new technology high voltage generators?

M
 
W

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

Jan 1, 1970
0
I'm curious whether anyone has dissected any of the latest version of
personal air purifiers? They are also sold as usb port plug ins to
purify the air near your computer...and, still others are sold to
purify the air in your car. They are sometimes called negative ion
generators and the sellers claim that breathing the ozone they produce
is supposed to improve your health:>: They usually include 'piezo' in
the title of the product.

"Piezo" comes from the method used to produce high voltage, which
produces the ozone (or negative ions as the sellers like to put it).
Piezo technology means piezotransformer or piezoelectric transformer
or piezo transformer, they go by a few different names. I'm fascinated
by these devices and want to learn more, especially regarding the
drivers.

I was wondering whether anyone had taken any of these units apart or
whether there are any websites dedicated to sharing information about
these new technology high voltage generators?

In one dept at work, a lady has some allergy, so she has to run this
'air purifier'. I went in there to do some work, and my eyes started
burning. The ozone smell was awful. I told them that ozone is bad for
you when it's this strong, and ozone is one of the bad components of
smog. Later when I had some time, I did a web search for ozone and air
purifiers, and I found that some of these supposedly air purifiers put
out way too much ozone and pollute tha air. I suggest you check those
out to find out more about the bad effects of breathing ozone.

As for piezo transformers, they seem to be a cheaper way of doing what
has been done for more than a hundred years, with simply a lot of very
thin wire and some iron for the core to wind it on. You can make tens
of thousands of volts with a flyback and tripler.

Also some sellers make claims about their products that are
unsubstantiated, such as their effectiveness in a large area. If you
use one of these small devices in a small closed room, they may be
effective, but if they're in a cubicle in a large room, it's doubtful
they can be of any halp.
 
M

Mebart

Jan 1, 1970
0
Thanks for writing. I belong to the Indoor Air Quality mailing list
and ozonec is a popular topic, so I'm fairly well versed in the ozone
matter.

The short version is that no ozone level is safe-the EPA has stopped
just short of this declaration because they have a mandate to keep the
air clean and they can't admit that they aren't doing their mandated
function:>:

I read all the ebay auctions for these devices, and they all have
ozone sections, claiming that the units they sell only produce XX
units of ozone.....but they leave out the part about the volume of air
that the results are spec'd for. Obviously I can put a small ozone
generator in a large auditorium and measure no increase in ozone. But
leaving out the volume of the room where the results were obtained is
like measuring the carbon monoxide output of an engine that's upwind
of the measuring device...'nuff said.

Somehow though, people continue to pay for these things, so the
auction prices never drop low enough for me to afford to buy any to
dissect. As PTB said, "there is a sucker born every minute".

The Customs department confiscates these things as they catch them
coming into the US, and the FDA shuts down sellers when they find
them. But, small time sellers (such as ebay sellers) fly under the
radar and seem to get away with it.

I'm interested in the driver circuit itself, which doesn't seem to be
documented. I know about the constant current mode which varies the
frequency of the driver in order to regulate the output current. I'm
interested in ultra low power high voltage generation, so want
something that is efficient and runs in constant voltage more (by
fixed frequency operation at the resonant frequency, and by varying
the sine wave input drive signal amplitude). I think driving it with a
sine wave avoids the ZVS problem that plaques square wave input signal
operation. As far as I know, this means 'I have to roll my own'
driver.

My guess is that this is how the personal ozone generators operate,
although they probably aren't as concerned with efficiency of the
driver as I would be.

M


to sned a reeply via emall, use anonymousone aatt thedoghousemail
ddoot ccomm ddoot ccomm
 
W

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

Jan 1, 1970
0
<Mebart> wrote in message

[snip]
The Customs department confiscates these things as they catch them
coming into the US, and the FDA shuts down sellers when they find
them. But, small time sellers (such as ebay sellers) fly under the
radar and seem to get away with it.

Not if you report them. IIRC, Ebay has some clause in their Terms of
Use that says that the seller is not allowed to sell an item that breaks
the law. Things like 'email leads', just another way of saying email
addresses for spammers, are illegal, so some spammers are selling the
service where you pay for so many email blasts, and the seller does the
blasting. But it's still illegal if you go by the law(s) that say that
it's illegal to 'blast' spam to recipients without giving them the
ability to unsubscribe. Anyway, if these ozone devices are prohibited
or confiscated based on some federal law, then if they are reported to
Ebay and the report gives the law that is being broken, they should then
shut down the auction.

For awhile at least, until the BOFH sellers find a way around it.
I'm interested in the driver circuit itself, which doesn't seem to be
documented. I know about the constant current mode which varies the
frequency of the driver in order to regulate the output current. I'm
interested in ultra low power high voltage generation, so want
something that is efficient and runs in constant voltage more (by
fixed frequency operation at the resonant frequency, and by varying
the sine wave input drive signal amplitude). I think driving it with a
sine wave avoids the ZVS problem that plaques square wave input signal
operation. As far as I know, this means 'I have to roll my own'
driver.

From my experience, I would say that after a few tens or hundreds of
hours of operation the dust and pollution buildup reduces the resistance
of the insulation, and causes the high voltage to drop to some
ineffective level. Then it's necessary to clean the dust off, or else
use higher power to overcome the resistive drop. In any case, it seems
that low power has some serious drawbacks.
 
J

James Sweet

Jan 1, 1970
0
Thanks for writing. I belong to the Indoor Air Quality mailing list
and ozonec is a popular topic, so I'm fairly well versed in the ozone
matter.

The short version is that no ozone level is safe-the EPA has stopped
just short of this declaration because they have a mandate to keep the
air clean and they can't admit that they aren't doing their mandated
function:>:

I read all the ebay auctions for these devices, and they all have
ozone sections, claiming that the units they sell only produce XX
units of ozone.....but they leave out the part about the volume of air
that the results are spec'd for. Obviously I can put a small ozone
generator in a large auditorium and measure no increase in ozone. But
leaving out the volume of the room where the results were obtained is
like measuring the carbon monoxide output of an engine that's upwind
of the measuring device...'nuff said.

Somehow though, people continue to pay for these things, so the
auction prices never drop low enough for me to afford to buy any to
dissect. As PTB said, "there is a sucker born every minute".


They're a bit of a gimmick overall, but people will pay for them because
it's hard to prove whether or not they do any good, and they do mostly at
least filter the air which I suppose is better than nothing.

I have an ozone generator I built a while back which works well for
deoderizing but it's certainly not something I'd want running all the time.
I just put it in a room that's a bit smelly, plug it in, leave the room and
shut the door, then a half hour or so later unplug it and open the window to
air it out, does a nice job for that.
 
J

James Sweet

Jan 1, 1970
0
You can very effectively generate ozone with a voltage multiplier chain
connected directly to the AC mains, you just need a needle electrode.
 
R

Rich The Newsgroup Wacko

Jan 1, 1970
0
Thanks for writing. I belong to the Indoor Air Quality mailing list
and ozonec is a popular topic, so I'm fairly well versed in the ozone
matter.

Somebody should put these guys together with the ozone hole freaks -
maybe they'd average out. ;-P
 
W

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

Jan 1, 1970
0
James Sweet said:
<Mebart> wrote in message

They're a bit of a gimmick overall, but people will pay for them because
it's hard to prove whether or not they do any good, and they do mostly at
least filter the air which I suppose is better than nothing.

I have an ozone generator I built a while back which works well for
deoderizing but it's certainly not something I'd want running all the time.
I just put it in a room that's a bit smelly, plug it in, leave the room and
shut the door, then a half hour or so later unplug it and open the window to
air it out, does a nice job for that.

Anything that's rubber gets destroyed by ozone. I can leave rubber
bands around a few floppies, and a few months later they fall off, or
worse yet, turn to mush. If I lived and worked out in the countryu the
rubber bands might last for years.
 
W

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

Jan 1, 1970
0
L

Luhan Monat

Jan 1, 1970
0
Rich said:
Somebody should put these guys together with the ozone hole freaks -
maybe they'd average out. ;-P

I had a unit 20 years ago. Sold as an 'air purifier' and 'negative ion
generator'. What it did was ionize dirt particles in the air, the
particles then went looking for a place to ground themselves making a
big ugly black blotch on a nearby wall. Well, the Air was cleaner.
 
L

Luhan Monat

Jan 1, 1970
0
Rich said:
Somebody should put these guys together with the ozone hole freaks -
maybe they'd average out. ;-P

Also, I used to repair TV's. They are great 'air purifiers' too.
 
J

James Sweet

Jan 1, 1970
0
But that (Cockcroft-Walton array) requires many rectifiers and
capacitors. To see a schematic of one go here and click on the link.
http://www.web-ee.com/Schematics/Voltage Multiplier/Cockroft-Walton.ht
m

It's much cheaper if you use a simpler method.

What's simpler? You can make a driver for a surplus flyback transformer, or
use an oil burner ignition transformer if you can find one of those surplus,
but a multiplier ladder is dirt cheap, I've bought diodes by the hundreds on
ebay for a few dollars, and have seen many similar deals with capacitors.
Should be able to get 5-6kv for 5-10 bucks with some scrounging.
 
J

James Sweet

Jan 1, 1970
0
Plenty of ozone is created in the upper atmosphere by UV striking oxygen
molecules, but high concentrations of chlorine up there will break it down
as fast as it forms.
 
R

Rich Grise

Jan 1, 1970
0
Plenty of ozone is created in the upper atmosphere by UV striking oxygen
molecules, but high concentrations of chlorine up there will break it down
as fast as it forms.

So, tell me how chlorine, with a molecular weight of 71 (on average),
miraculously levitates to the top of a sea of oxygen, with its molecular
weight of 32, and nitrogen, with a molecular weight of 28?

Or better yet, Freon, which is so dense that it can be literally poured
from one container into another?

And how is it that this chlorine and freon and all those other boogeyman
gases happen to skip past the ozone that's polluting the cities, on their
way to the south pole?

There's no ozone over the south pole because most of the year there's
no sunlight there to make any.

Sigh. I lament the loss of science education these days.

Thanks,
Rich
 
R

R Adsett

Jan 1, 1970
0
So, tell me how chlorine, with a molecular weight of 71 (on average),
miraculously levitates to the top of a sea of oxygen, with its molecular
weight of 32, and nitrogen, with a molecular weight of 28?

Or better yet, Freon, which is so dense that it can be literally poured
from one container into another?

Which, of course, explains why the atmosphere has settled into layers of
Nitrogen, Oxygen and Carbon Dioxide amoungst others ;) And of course
water never rises higher than sea level.

Robert
 
K

keith

Jan 1, 1970
0
Which, of course, explains why the atmosphere has settled into layers of
Nitrogen, Oxygen and Carbon Dioxide amoungst others ;) And of course
water never rises higher than sea level.

Water has a molecular weight of 18, of course it's going to rise. ;-)
 
P

Pig Bladder

Jan 1, 1970
0
Which, of course, explains why the atmosphere has settled into layers of
Nitrogen, Oxygen and Carbon Dioxide amoungst others ;) And of course
water never rises higher than sea level.

Your pulse: 98.6. Very scientific.

Quant Suff!
 
R

R Adsett

Jan 1, 1970
0
Your pulse: 98.6. Very scientific.

Beg Pardon? An unusual dialect perhaps? I understand all the words but
I can't make any sense out of the phrase.

Robert
 
K

keith

Jan 1, 1970
0
Beg Pardon? An unusual dialect perhaps? I understand all the words but
I can't make any sense out of the phrase.

....not unusual.
 
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