Mystery flickering neons

[Nigel Cook]

I am aware that driving neons with DC not AC produces
a flicker effect (mock candle flame effect).
Just recently repaired an old Quad
valve/tube radio that uses flickering neon type devices
to indicate tuned in point.
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

e-mail (removing .....) diverse2@tcp.co.u.....k
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse

Nigel,Diverse Devices,Southampton,England

 

[Ron]

I'm not sure that DC will produce a flicker in a regular neon bulb unless
it's quite old or some special type. Also, I have observed that an external
light will tend to excite the gas in a dark neon bulb (powered) and make it
come on.
-Ron
San Diego, CA USA - Wildfire capital of the world
(email: replace 'abuse' with 'cyberguy3k')

"Nigel Cook" <diverse2@tcp.co.antispam.uk> wrote:
I am aware that driving neons with DC not AC produces
a flicker effect (mock candle flame effect).
Just recently repaired an old Quad
valve/tube radio that uses flickering neon type devices
to indicate tuned in point.
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

e-mail (removing .....) diverse2@tcp.co.u.....k
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse

Nigel,Diverse Devices,Southampton,England

 

[Sam Goldwasser]

Not quite sure what you question is but:

1. Neons when new don't flicker.

2. As they are run, the breakdown voltage goes up to the point where
starting on every cycle of the AC becomes marginal. They will be
very critical with respect to line voltage and harmonics on the line.

3. Some light may help starting.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.


"Nigel Cook" <diverse2@tcp.co.antispam.uk> writes:

I am aware that driving neons with DC not AC produces
a flicker effect (mock candle flame effect).
Just recently repaired an old Quad
valve/tube radio that uses flickering neon type devices
to indicate tuned in point.
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

e-mail (removing .....) diverse2@tcp.co.u.....k
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse

Nigel,Diverse Devices,Southampton,England

 

[James Sweet]

"Ron" <abuse@hotmail.com> wrote in message
news:wqenb.71765$th6.25793@twister.socal.rr.com...

I'm not sure that DC will produce a flicker in a regular neon bulb unless
it's quite old or some special type. Also, I have observed that an
external
light will tend to excite the gas in a dark neon bulb (powered) and make
it
come on.
-Ron

Yeah they don't flicker on DC, but only one of the two electrodes will
light, so lifetime is reduced significantly. The glow is only around the
cathode, this is what allows Nixie and Panaplex type displays to work so
well. When run off AC the anode and cathode switch with every cycle so both
electrodes glow.

 

[Bob Parker]

If I remember correctly, neon lamps usually have a microscopic amount
of radon gas in them to stabilize/reduce the striking voltage. Also
I've read that when very close to their striking voltage, they can be
triggered into striking by exposure to infra-red radiation as well as
visible light. Useless information, isn't it?

Bob


Sam Goldwasser <sam@saul.cis.upenn.edu> wrote:

Not quite sure what you question is but:

1. Neons when new don't flicker.

2. As they are run, the breakdown voltage goes up to the point where
starting on every cycle of the AC becomes marginal. They will be
very critical with respect to line voltage and harmonics on the line.

3. Some light may help starting.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[Sam Goldwasser]

Bob Parker <bobp@bluebottle.com> writes:

If I remember correctly, neon lamps usually have a microscopic amount
of radon gas in them to stabilize/reduce the striking voltage. Also
I've read that when very close to their striking voltage, they can be
triggered into striking by exposure to infra-red radiation as well as
visible light. Useless information, isn't it?

I think they may have done away with the radioactive trace on health/safety
grounds. The information isn't totally useless. Afterall, it allowed
you to create a packet of bits with an information content better than
entropy would permit and distribute it to the far ends of the Globe.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[Jerry G.]

A properly working neon lamp should not flicker, unless designed to do so.
When they are aged and ward down, they may start to flicker.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Nigel Cook" <diverse2@tcp.co.antispam.uk> wrote in message
news:BoidnfghOJMw8QCiRVn-tA@tcp.co.uk...
I am aware that driving neons with DC not AC produces
a flicker effect (mock candle flame effect).
Just recently repaired an old Quad
valve/tube radio that uses flickering neon type devices
to indicate tuned in point.
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

e-mail (removing .....) diverse2@tcp.co.u.....k
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse

Nigel,Diverse Devices,Southampton,England

 

[John Robertson]

On 27 Oct 2003 18:46:47 -0500, Sam Goldwasser <sam@saul.cis.upenn.edu>
wrote:

Bob Parker <bobp@bluebottle.com> writes:

If I remember correctly, neon lamps usually have a microscopic amount
of radon gas in them to stabilize/reduce the striking voltage. Also
I've read that when very close to their striking voltage, they can be
triggered into striking by exposure to infra-red radiation as well as
visible light. Useless information, isn't it?

I think they may have done away with the radioactive trace on health/safety
grounds. The information isn't totally useless. Afterall, it allowed
you to create a packet of bits with an information content better than
entropy would permit and distribute it to the far ends of the Globe.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
....

You need to give Bob more credit than that Sam...if Planet Internet
(or whoever was sending the Internet to a satellite for down links) is
still running then Bob's info is now happily being beamed out to the
galaxy at large! Perhaps 1st contact!!!

John :-#)#
(Please post followups or tech enquires to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Bruce]

I think its wonderfull so many know about a technology that died around the
first episodes of Star Trek
makes great reading !!
"Nigel Cook" <diverse2@tcp.co.antispam.uk> wrote in message
news:BoidnfghOJMw8QCiRVn-tA@tcp.co.uk...

I am aware that driving neons with DC not AC produces
a flicker effect (mock candle flame effect).
Just recently repaired an old Quad
valve/tube radio that uses flickering neon type devices
to indicate tuned in point.
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

e-mail (removing .....) diverse2@tcp.co.u.....k
electronic hints and repair briefs , schematics/manuals list on
http://homepages.tcp.co.uk/~diverse

Nigel,Diverse Devices,Southampton,England

 

[Bob Parker]

John Robertson <jrr@flippers.com> wrote:

You need to give Bob more credit than that Sam...if Planet Internet
(or whoever was sending the Internet to a satellite for down links) is
still running then Bob's info is now happily being beamed out to the
galaxy at large! Perhaps 1st contact!!!

If there's anyone out there in the Galaxy intercepting this stuff
in a few (light-)years' time, it will be Sam's great knowledge they
will judge the development of Planet Earth on, not my ramblings about
neon tubes striking when exposed to photons!


"Bruce" <Montypythom@hotmail.com> wrote:

I think its wonderfull so many know about a technology that died around the
first episodes of Star Trek
makes great reading !!

You mean that your current-generation (no pun intended) power
outlets don't have little neon lamps in them? Ours Down Under still
do!

 

[Sam Goldwasser]

Bob Parker <bobp@bluebottle.com> writes:

You mean that your current-generation (no pun intended) power
outlets don't have little neon lamps in them? Ours Down Under still
do!

Do they flicker?

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.

 

[M. G. Devour]

Nigel wrote:

For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

I have to agree that the ambient light level must ionize the gas enough to
cause what you're seeing. I've seen another demonstration of that very
effect recently.

I bought one of those little flashlights that have "white" LED's and an
incandescent bulb in the reflector at one end, and a cold cathode
flourescent tube behind a lens on the side of the handle. The switch lets
you cycle between the 3 modes and off.

In any very dark room, the darn flourescent tube will *not* light unless
it's stimulated by a few photons from another source. I've tried reflecting
some of the light out of the end back onto the handle and then switching it.
That works, but it is physically hard to do. A tiny flicker from another
penlight flashlight will cause it to light off immediately, as will walking
into a lighted area. Also the phosphor on my watch face puts out enough
radiation of some kind to help the tube light.

Once it lights the first time it will re-light, at least for a while. I've
not tested to see just how long it stays "hot" enough to work, though.

It sure took me a while to figure it out. I bet that it lit very reliably at
the factory. I'm sure they don't assemble them in total darkness! <grin>

Be well,

Mike D.

 

[John Robertson]

I was reading on one web site about fluorescent lights and they were
talking of a silicon film that is on these tubes...and that if the
film is missing the tube won't start well...

http://www.advancetransformer.com/literature/pdf/FLB_Pocket_Guide.pdf

Great reading!

John :-#)#

On Tue, 28 Oct 2003 11:09:42 -0500, "M. G. Devour"
<mdevour@eskimo.com> wrote:

Nigel wrote:
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

I have to agree that the ambient light level must ionize the gas enough to
cause what you're seeing. I've seen another demonstration of that very
effect recently.

I bought one of those little flashlights that have "white" LED's and an
incandescent bulb in the reflector at one end, and a cold cathode
flourescent tube behind a lens on the side of the handle. The switch lets
you cycle between the 3 modes and off.

In any very dark room, the darn flourescent tube will *not* light unless
it's stimulated by a few photons from another source. I've tried reflecting
some of the light out of the end back onto the handle and then switching it.
That works, but it is physically hard to do. A tiny flicker from another
penlight flashlight will cause it to light off immediately, as will walking
into a lighted area. Also the phosphor on my watch face puts out enough
radiation of some kind to help the tube light.

Once it lights the first time it will re-light, at least for a while. I've
not tested to see just how long it stays "hot" enough to work, though.

It sure took me a while to figure it out. I bet that it lit very reliably at
the factory. I'm sure they don't assemble them in total darkness! <grin

Be well,

Mike D.

(Please post followups or tech enquires to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Bob Parker]

Sam Goldwasser <sam@saul.cis.upenn.edu> wrote:

Bob Parker <bobp@bluebottle.com> writes:

You mean that your current-generation (no pun intended) power
outlets don't have little neon lamps in them? Ours Down Under still
do!

Do they flicker?

Yes, they often do! Especially when they've been constantly switched
on for a few years.

Bob

 

[Nigel Cook]

"M. G. Devour" <mdevour@eskimo.com> wrote in message
news:bnm4c5$n5f$1@eskinews.eskimo.com...

Nigel wrote:
For ages i've noticed the neon on my bench power supply
flickers according to what else is in use electrically.
A room lamp if on then neon goes out but as its on a dimmer
and i turn it down to 30% or so or less ,then the neon
comes on. Happens with ordinary filament lamps on
the lighting circuit - the ps is off the power ring main.
Just curious - any ideas ?

I have to agree that the ambient light level must ionize the gas enough to
cause what you're seeing. I've seen another demonstration of that very
effect recently.

I bought one of those little flashlights that have "white" LED's and an
incandescent bulb in the reflector at one end, and a cold cathode
flourescent tube behind a lens on the side of the handle. The switch lets
you cycle between the 3 modes and off.

In any very dark room, the darn flourescent tube will *not* light unless
it's stimulated by a few photons from another source. I've tried
reflecting
some of the light out of the end back onto the handle and then switching
it.
That works, but it is physically hard to do. A tiny flicker from another
penlight flashlight will cause it to light off immediately, as will
walking
into a lighted area. Also the phosphor on my watch face puts out enough
radiation of some kind to help the tube light.

Once it lights the first time it will re-light, at least for a while. I've
not tested to see just how long it stays "hot" enough to work, though.

It sure took me a while to figure it out. I bet that it lit very reliably
at
the factory. I'm sure they don't assemble them in total darkness! <grin

Be well,

Mike D.

I tried a few photons (IR) from a few zappers and
(visible) from a torch but nothing
from the ps neon.

 

[Bob Parker]

G'day,
That's really interesting. Thanks!

Bob


John Robertson <jrr@flippers.com> wrote:

I was reading on one web site about fluorescent lights and they were
talking of a silicon film that is on these tubes...and that if the
film is missing the tube won't start well...

http://www.advancetransformer.com/literature/pdf/FLB_Pocket_Guide.pdf

Great reading!

John :-#)#

 

[M. G. Devour]

Nigel writes:

I tried a few photons (IR) from a few zappers and
(visible) from a torch but nothing
from the ps neon.

Well, so much for the photonic stimulation theory! <grin>

Those neon bulbs certainly have a finite lifespan. After a while they seem
to start flickering and behaving strangely, like yours. I guess I don't know
the mechanism.

Mike D.

 

[James Sweet]

"M. G. Devour" <mdevour@eskimo.com> wrote in message
news:bnmrg4$5n3$1@eskinews.eskimo.com...

Nigel writes:
I tried a few photons (IR) from a few zappers and
(visible) from a torch but nothing
from the ps neon.

Well, so much for the photonic stimulation theory! <grin

Those neon bulbs certainly have a finite lifespan. After a while they seem
to start flickering and behaving strangely, like yours. I guess I don't
know
the mechanism.

Mike D.

There's one on the power strip right under my desk here that flickers, when
I turn the room light off it usually goes out, if I point a flashlight at it
the neon fires right up with relatively little flickering, so the photonic
stimulation theory certainly applies in some cases.

 

[Nigel Cook]

There's one on the power strip right under my desk here that flickers,
when
I turn the room light off it usually goes out, if I point a flashlight at
it
the neon fires right up with relatively little flickering, so the photonic
stimulation theory certainly applies in some cases.

That's a relief, I thoukht it might be ESP / Telekinesis on my part

 

[Asimov]

"M. G. Devour" bravely wrote to "All" (28 Oct 03 17:44:04)
--- on the heady topic of "Re: Mystery flickering neons"

Could be the neon gas is slowly vented to the outside and conversely
possibly some outside contamination gets into the envelope through the
seal in the glass/electrode interface, humidity comes to mind. The
electrodes may also vaporize a very tiny bit into the gas or become
pitted when the neon is hit by powerline voltage spikes. I recall neon
lamps sometimes being used as clamps around high voltage sensitive
circuits. And as Bob said the trace radiological striker has a shortish
half-life.


MGD> From: "M. G. Devour" <mdevour@eskimo.com>

MGD> Nigel writes:

I tried a few photons (IR) from a few zappers and
(visible) from a torch but nothing
from the ps neon.

MGD> Well, so much for the photonic stimulation theory! <grin>

MGD> Those neon bulbs certainly have a finite lifespan. After a while they
MGD> seem to start flickering and behaving strangely, like yours. I guess I
MGD> don't know the mechanism.

MGD> Mike D.

.... Techs would rather pee on an electric fence for the light show