Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #11   Report Post  
Old June 27th 17, 10:04 AM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Jan 2015
Posts: 12,364
Default [Q] dimmer switch for halogen floor lamp

On Monday, 26 June 2017 23:14:32 UTC+1, John Robertson wrote:
On 2017/06/26 2:18 PM, tabbypurr wrote:
On Monday, 26 June 2017 20:59:17 UTC+1, Ian Field wrote:
tabbypurr wrote in message
...
On Sunday, 25 June 2017 22:11:59 UTC+1, Ian Field wrote:
wrote in message
...
Yeah, another Googler. I am oe but I do not drege up decades old posts,
I
just use it because...

But the thing is you are really not supposed to din halogen lamps
because
then the halogen is not sufficiently activated to allow the filament to
operate in the higher range, which is the whole idea of halogen lamps.

Its all about the; "halogen cycle" - vapourised tungsten recirculates and
condenses back on the filament. Under a critical temperature, it deposits
on
the inside of the envelope just like regular bulbs.

but slowly. And when full powered it then cleans itself.

You'd have to get the quartz envelope seriously hot to do that - like
glowing so white it gave off UV.


AIUI they're self cleaning at rated voltage.


When they are RUN at the rated voltage and power. If you dim them the
tungsten is deposited on the quartz and short of heating the quarts to
white hot (above poster's remarks) the tungsten is going to STAY on the
quartz, not recoating on the filament.

http://www.topbulb.com/blog/dimming-...halogen-cycle/

In other words don't do it.

John


That may be your belief. IRL halogen stage lighting works just fine.


NT

  #12   Report Post  
Old June 27th 17, 10:10 AM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Aug 2014
Posts: 1,249
Default [Q] dimmer switch for halogen floor lamp

wrote:

---------------------------

http://www.topbulb.com/blog/dimming-...halogen-cycle/

In other words don't do it.

John


That may be your belief. IRL halogen stage lighting works just fine.



** A better example to use is the hundreds of MILLIONS of 12V * halogen down lights* installed in homes - nearly al of which are run on dimmers.

Users get mood light when needed PLSU a *large increase* in life span.

QED.



..... Phil




  #13   Report Post  
Old June 27th 17, 02:52 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Dec 2008
Posts: 811
Default [Q] dimmer switch for halogen floor lamp

On Sunday, June 25, 2017 at 7:53:16 AM UTC-4, wrote:
Yeah, another Googler. I am oe but I do not drege up decades old posts, I just use it because...


Google does display the date
m
  #14   Report Post  
Old June 27th 17, 07:44 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Apr 2017
Posts: 122
Default [Q] dimmer switch for halogen floor lamp



"John Robertson" wrote in message
...
On 2017/06/26 2:18 PM, wrote:
On Monday, 26 June 2017 20:59:17 UTC+1, Ian Field wrote:
tabbypurr wrote in message
...
On Sunday, 25 June 2017 22:11:59 UTC+1, Ian Field wrote:
wrote in message
...
Yeah, another Googler. I am oe but I do not drege up decades old
posts,
I
just use it because...

But the thing is you are really not supposed to din halogen lamps
because
then the halogen is not sufficiently activated to allow the filament
to
operate in the higher range, which is the whole idea of halogen
lamps.

Its all about the; "halogen cycle" - vapourised tungsten recirculates
and
condenses back on the filament. Under a critical temperature, it
deposits
on
the inside of the envelope just like regular bulbs.

but slowly. And when full powered it then cleans itself.

You'd have to get the quartz envelope seriously hot to do that - like
glowing so white it gave off UV.


AIUI they're self cleaning at rated voltage.


When they are RUN at the rated voltage and power. If you dim them the
tungsten is deposited on the quartz and short of heating the quarts to
white hot (above poster's remarks) the tungsten is going to STAY on the
quartz, not recoating on the filament.

http://www.topbulb.com/blog/dimming-...halogen-cycle/

In other words don't do it.


I wouldn't go so far as "don't do it" - if you're dimming it, a little
shading probably isn't that much of a problem anyway.

The manufacturers say "don't do it " to cover their asses.

  #15   Report Post  
Old June 27th 17, 07:47 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Apr 2017
Posts: 122
Default [Q] dimmer switch for halogen floor lamp



"Phil Allison" wrote in message
...
John Robertson wrote:

----------------------


When they are RUN at the rated voltage and power. If you dim them the
tungsten is deposited on the quartz and short of heating the quarts to
white hot (above poster's remarks) the tungsten is going to STAY on the
quartz, not recoating on the filament.

http://www.topbulb.com/blog/dimming-...halogen-cycle/


** That is merely one person's opinion, not backed up with evidence.

Wiki says differently :

https://en.wikipedia.org/wiki/Haloge...on_performance

Stage lighting uses dimming all the time with halogen lamps and there is
no blackening or short life experienced - the lamps run much longer as
expected.

The claim that the "halogen cycle" puts metal back on the filament is true
but it does not deposit it back where it came from so has little effect on
lamp life.

Most halogen lamps are low voltage or high powered - so in both cases the
filaments are thicker than typical non halogen examples.


Wrong - the filament surface get distinctly granular and weak spots are
inevitable. With DC, the tungsten actually migrates along the filament
length - it gets thinner at one end, and guess what happens next.



  #16   Report Post  
Old June 27th 17, 07:50 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Apr 2017
Posts: 122
Default [Q] dimmer switch for halogen floor lamp



wrote in message
...
On Monday, 26 June 2017 23:14:32 UTC+1, John Robertson wrote:
On 2017/06/26 2:18 PM, tabbypurr wrote:
On Monday, 26 June 2017 20:59:17 UTC+1, Ian Field wrote:
tabbypurr wrote in message
...
On Sunday, 25 June 2017 22:11:59 UTC+1, Ian Field wrote:
wrote in message
...
Yeah, another Googler. I am oe but I do not drege up decades old
posts,
I
just use it because...

But the thing is you are really not supposed to din halogen lamps
because
then the halogen is not sufficiently activated to allow the
filament to
operate in the higher range, which is the whole idea of halogen
lamps.

Its all about the; "halogen cycle" - vapourised tungsten
recirculates and
condenses back on the filament. Under a critical temperature, it
deposits
on
the inside of the envelope just like regular bulbs.

but slowly. And when full powered it then cleans itself.

You'd have to get the quartz envelope seriously hot to do that - like
glowing so white it gave off UV.

AIUI they're self cleaning at rated voltage.


When they are RUN at the rated voltage and power. If you dim them the
tungsten is deposited on the quartz and short of heating the quarts to
white hot (above poster's remarks) the tungsten is going to STAY on the
quartz, not recoating on the filament.

http://www.topbulb.com/blog/dimming-...halogen-cycle/

In other words don't do it.

John


That may be your belief. IRL halogen stage lighting works just fine.


It wouldn't be any surprise if stage lighting is over run for short
periods - filament failure probably makes shading nothing more than a trade
off.

  #17   Report Post  
Old June 27th 17, 09:57 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Aug 2014
Posts: 1,249
Default [Q] dimmer switch for halogen floor lamp

Ian Field wrote:

---------------------


When they are RUN at the rated voltage and power. If you dim them the
tungsten is deposited on the quartz and short of heating the quarts to
white hot (above poster's remarks) the tungsten is going to STAY on the
quartz, not recoating on the filament.

http://www.topbulb.com/blog/dimming-...halogen-cycle/


** That is merely one person's opinion, not backed up with evidence.

Wiki says differently :

https://en.wikipedia.org/wiki/Haloge...on_performance

Stage lighting uses dimming all the time with halogen lamps and there is
no blackening or short life experienced - the lamps run much longer as
expected.

The claim that the "halogen cycle" puts metal back on the filament is true
but it does not deposit it back where it came from so has little effect on
lamp life.

Most halogen lamps are low voltage or high powered - so in both cases the
filaments are thicker than typical non halogen examples.


Wrong ....



** So they are actually thinner are they ??


FOAD you ridiculous, know nothing bloody troll.




...... Phil


  #18   Report Post  
Old June 27th 17, 10:00 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Aug 2014
Posts: 1,249
Default [Q] dimmer switch for halogen floor lamp

Ian ****wit Field wrote:

------------------------------


That may be your belief. IRL halogen stage lighting works just fine.


It wouldn't be any surprise .



** Any fact whatever would be HUGE surprise to a ****wit like you.


if stage lighting is over run for short periods


** Errr - dimmers only dim lamps down, not up.

****wit.




....... Phil
  #19   Report Post  
Old June 28th 17, 06:52 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Apr 2017
Posts: 122
Default [Q] dimmer switch for halogen floor lamp



"Phil Allison" wrote in message
...
Ian ****wit Field wrote:

------------------------------


That may be your belief. IRL halogen stage lighting works just fine.


It wouldn't be any surprise .



** Any fact whatever would be HUGE surprise to a ****wit like you.


if stage lighting is over run for short periods


** Errr - dimmers only dim lamps down, not up.


They don't get any dimmer than you - some stage lighting used variacs that
went up to 110%.

  #20   Report Post  
Old June 28th 17, 08:04 PM posted to sci.electronics.repair
external usenet poster
 
First recorded activity by DIYBanter: Mar 2007
Posts: 1,625
Default [Q] dimmer switch for halogen floor lamp

It is often assumed that incandescent and halogen light bulbs are completely different technologies. In fact, halogen is just a hybrid incandescent.

Both types of light bulbs use a tungsten filament. Both “burn out” when the filament breaks. Both use line and low voltage the same way.

Also, both incandescent and halogen bulbs can be dimmed. But here’s the interesting twist: the more a halogen bulb is dimmed, the more it becomes an incandescent light bulb again.

How Incandescent and Halogen Differ
The standard incandescent bulb is filled with a mixture of argon gas and a small amount of nitrogen gas. Inside this gas mix, the tungsten filament, heated to “incandescence”, slowly evaporates. Thinner portions of the filament get hotter and they evaporate more quickly. The evaporated tungsten deposits on the inside wall of the glass. Eventually, the filament evaporates so much tungsten that it breaks or “burns out”.

A halogen bulb mimics the technology of incandescent except for two features. First, the filament and gas are contained in a quartz capsule resistant to high temperature. Second, a halogen gas such as bromine or iodine is added to the gas mix. With this gas mixture and higher filament temperatures, a chemical change occurs to the tungsten filament evaporation process. Instead of depositing the evaporated tungsten on the bulb glass, it is deposited instead back onto the filament itself. This process of filament regeneration is known as the halogen cycle. It can double the life of an incandescent bulb.

In short the primary difference between halogen and incandescent is the existence of the halogen cycle operating in a quartz capsule.

Dimming Halogen Lights and Bulb Life
That brings us back to dimming.

Dimming works the same way for both incandescent and halogen. Lower the filament temperature by modifying the voltage and get progressively less light output. The halogen cycle works only at high filament temperatures. If the halogen bulb is dimmed enough (down to only 20% less light), the filament temperature drops and the halogen cycle stops. At that point, it is operating in “incandescent mode” with evaporated tungsten being deposited on the capsule wall rather than back on the filament.

Tip: While dimming often lengthens the life of incandescent bulbs, it may shorten the life of halogen bulbs and cause darkening of the quartz capsule.

Thanks to: David Burtner

http://www.topbulb.com/blog/dimming-...halogen-cycle/

Key Points:

a) Halogen lamps are hybrid incandescent lamps. We knew that.
b) The "Halogen Cycle" redeposits tungsten on the filament as compared to a standard incandescent lamp that gradually evaporates the tungsten.
c) The halogen cycle stops at around 20% LESS LIGHT. That would be at/around 80% of full light. Whereupon the lamp behaves as a standard incandescent lamp.
d) With all this in mind, a halogen lamp may be dimmed with the same technology, means and methods as a standard incandescent lamp. Primary effects are on life-span. The failure modes are unchanged, eventually the filament fails.

It ain't nohow rocket science.

Anyone with even a passing experience with lighting already knows all this -as well as even the lowliest sweeper at any given electrical supply house.

Peter Wieck
Melrose Park, PA


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wire Mesh Safety Grill For Halogen Bulb Torchiere Floor Lamp ? Robert11 Home Repair 5 November 12th 07 03:35 AM
Can I Remove the InLine Dimmer Switch in a Floor Lamp? Jay Chan Home Repair 3 March 19th 07 09:29 PM
Pole Lamp Dimmer/Switch Module Robert11 Home Repair 4 January 8th 07 10:56 PM
Fitting a dimmer switch to a floor lamp - No Earth [email protected] UK diy 23 November 22nd 05 05:15 PM
dimmer switch with pull string switch Andy Saggers UK diy 2 March 10th 04 10:18 PM


All times are GMT +1. The time now is 10:37 PM.

Powered by vBulletin® Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Copyright 2004-2022 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017