Transformer 20 to 30 KV

[Dave]

Thanks Greg

I thought it would have to be something like that but wondered if it
might be something more esoteric.

Dave


On Mon, 20 Oct 2003 08:44:23 GMT, "gcd" <gcdnoSPAM@austarmetro.com.au>
wrote:

Hi Dave,
AFAIK Aus post use them in work on the ir readers (mail sorters) of the pink
or invisible bar codes

Cheers
Greg


"Dave" <dave50_8@hotmail.com> wrote in message
news:kkt6pv0thebmb0o6itglis3kd4hhl9tdk0@4ax.com...
OK I admit defeat !

What does Aus Post use these IR detection sticks for ?

Dave

On Tue, 14 Oct 2003 08:05:30 GMT, "gcd" <gcdnoSPAM@austarmetro.com.au
wrote:

**HERE IT IS AGAIN COS MY ISP DECIDED THIS MESSAGE HAD BEEN ROUND LONG
ENOUGH AFTER 3-4HRS AND NUKED IT? - sorry to those who see this twice cos
they have superior ISPs**

Hi Don,
yes have some info that follows.

Its a Kodak IR detection Stick 0.7 - 1.3um Translucent, # 27535Z, Cat 827
8673. These are used by Aus post.

It has a small section of phosphorescent material which is sensitive to
IR
radiation and emits visible red.

Have fun........ safe fun that is

Cheers
Greg

"Don Reinoga" <dreinoga@dontvirusmebigpond.net.au> wrote in message
news:3F89EAD9.7D3A046B@dontvirusmebigpond.net.au...
Opps forgot to ask, any more info on those IR Sticks?

Thanks

Don Reinoga wrote:

Thanks Guys,

Spot on re the type of laser, Class 4 Sealed 1 meter CO2 tube.Saftey
glass def
in use. We get some great beam reflections off a hard disk platter

The neon sign transformer we have it a 15KV rated to 60mA, which is
more
than we
need, and we are having some difficulty finding a resister rated to
225Watts.
We have got together 60 odd diodes for our bridge rectifer, which is
working
fine.

The voltage doubler sounds like the way to go, this would give the
required
voltage and reduce the current as well. We are using a variac to
slowly
bring up
the voltage till we get lasing.

Got to stuff from http://www.circlec.com.au

Prefer not to pull apart the neon sign transformer, its a sealed
unit.
So I will
investigate the voltage doubler.

I can't wait for my focusing lens to arrive....

Thanks, Don

gcd wrote:

Hi,
I'll give to your better knowledge on neon stuff. I've seen info on
both
current limited centre tapped transformers for neon and elsewhere
stuff
about high frequency ac and also dc.

Perhaps I'm confused, thinking about my HeNe lasers which use high
voltage
dc.

Simplest solution - talk to a transformer manufacturer and get one
made. Not
sure if they do that voltage rating but try Tortech in Sydney, I've
used
them for high power transformers and inductors in the past with
great
success. There is also a mob here in Melb I've used for isolation
transformers to my spec, Altro transformers, you could try them.

For the CO2 laser, he wants a DC supply, so a rectifier will be
needed
with
current limiting if you don't want to damage the HV secondary in
the
event
of an accident.

op fyi
from the ANU

Class 1 - laser devices are safe for use under all conditions of
exposure,
based upon current medical knowledge. This class includes all
lasers
or
laser systems that cannot emit levels of optical radiation above
the
exposure limits for the eye under any exposure conditions inherent
in
the
design of the laser product. However, caution should be expressed
when
repairing a class 1 laser product, as a higher class laser may be
embedded
within it.

Class 2- laser or laser system emit a visible laser beam, which by
its
very
bright nature will be too dazzling to stare into for extended
periods.
Momentary viewing is not considered hazardous, with potential
damage
to the
eyes avoided by normal blink and aversion responses (turning head,
looking
away etc). class 2 lasers are only in the visible spectrum. Some
controls
to prevent direct staring are required.

Class 3 - laser or laser system can emit any wavelength, but it
cannot
produce a diffuse (scattered) reflection hazard unless focused or
viewed for
extended periods at close range. These lasers are of medium to
high
power
and risk (output power is 0.5 W or less). They emit radiation that
is
hazardous to the eye, but not a serious skin hazard. More
stringent
controls are required, concentrating on eliminating intra-beam
viewing.
Class 3 is further divided into:

Class 3A - mainly (visible) medium power lasers, (less than 5 mW in
visible). Marginal eye hazard. The beam must be expanded to an
irradiance
of less than 25 Wm-2, to ensure that only 1 mW or less can enter
the 7
mm
pupil.

Class 3B (restricted) - medium to high power visible lasers with
more
stringent conditions of use. These are usually restricted to
daylight
conditions where the pupil size is less than 5 mm in diameter.
(eg.
outdoor
lasers in the construction industry). They operate at similar
power
levels
to a class 3A laser, but have higher levels of irradiance (up to 50
Wm-2).
If used in low light conditions, the controls for a class 3B laser
are
appropriate. This classification is unique to Australia.

Class 3B - mainly medium to high power lasers, with many operating
in
the
non - visible spectrum. Significant eye hazard (up to 500 mW in
visible).
Diffuse reflection viewing is only safe if exposure is less than 10
s
and
the distance to the reflecting surface is greater then 130 mm.

Class 4 - laser or laser system is any that exceeds the output
limits
(Accessible Emission Limits, AELs) of a Class 3 device. These
lasers
are of
high power and risk. They are capable of producing diffuse
reflections
hazardous to the eye and skin. They may be a fire risk. Very
stringent
control measures are required for a Class 4 laser or laser system.

You are using a class 4 laser.

Cheers
Greg

"Vermin" <Vermin@nowhere.com> wrote in message
news:hhqcovk5mnjan9qc6a1etf6jkdrmpdlomp@4ax.com...
On Fri, 10 Oct 2003 07:53:16 GMT, "gcd"
gcdnoSPAM@austarmetro.com.au
wrote:

**RESENDING THIS AS MY ISP IS ROOTED**


Hi all,
Neon transformers are usually either DC output or high frequency
AC
output
(given your application I suggest you have a DC unit).

No, they output 50 or 60 Hz AC (depending on supply and country
of
origin).

There are modern switch mode versions (I don't know what they
output)
but the majority are still just step up transformers.


So either way you are not going to be able to do to much with
it,
ie you
cannot run it into an ignition coil.

Agreed, but for different reasons (you can't put 15kV into a coil
rated for 12v, well you could but it would break down the
insulation).


If you are able to remove the internal rectifier (highly
unlikely),
you
could use 2 of these transformers with the secondaries in series
and then
rectify to produce 30kV @ 30mA. Make sure you get the phasing
right! and
use
safety cut outs etc.


No you can't, see my previous post regarding center tapped earth.

Or again if you can remove the rectifier, you could replace it
with
a
voltage doubling rectifier to get the 30kV, with a little less
than
15mA
out - depending on how effecient the doubler is.


Voltage doubling is feasible but would not give him increased
power
input due to reduced current and inefficiencies in the doubler.

I know very little about lasers so I wont comment on the rest.

Vermin.