Easier way to turn off the backlight?

Originally from the "Re: Laptop backlight quitting intermittently"
thread

shockwa wrote:
> I was having an issue with a new LCD and inverter. The backlight
> still wasnt functioning. Then someone told me about the "toggle
> switch" that turns the backlight on or off when the lid is opened and
> closed. Supposed to be near the keyboard. Maybe it has a short or
> isn't functioning.

My manual claims that my Gateway MX6124 notebook turns the screen off
when I close the lid (they say to conserve battery power). But it
doesn't (even on battery power). Although it does allow the power
options to be set where it will go into Standby or Hibernation. I
currently have it set to do nothing when I close the lid. So while the
manual is correct for if you use H or S, it is incorrect if you want the
notebook still running.

I would love to be able to turn off the backlight. As my notebook is on
almost 24/7 and some of the time I don't need the backlight. And closing
the lid only causes the laptop to get much warmer while it is running
(this notebook does run very cool though, which is nice). I can dim it,
but not turn it off easily. And I'm not convinced that dimming actually
extends the life of the tube and inverter anyway.

So the only way I know how to turn off the lamp is by adjusting the
power scheme in the Power Options Properties. PIA to go in there and
change it for 1 minute though every time I want the lamp off. The plus
side is that it turns off my extended monitor as well.

--
Bill

Dimming will definitely extend the life of the lamp. The life of the
inverter isn't really a function of how much it's used. It's a solid
state electronic device. It will fail, at some point, or it might last
3 or more decades without ever failing, but in either case the extent of
it's use isn't necessarily a factor in how long it lasts.

On most laptops, if you activate the lid closed switch without turning
the laptop off, yes, the lamp shuts down, but the laptop also begins
beeping ... this is considered an error condition. It might be more
effective, as you have done, to just set the settings in power
management to shut down the screen after a relatively short period of
inactivity.



BillW50 wrote:
> Originally from the "Re: Laptop backlight quitting intermittently"
> thread
>
> shockwa wrote:
>
>>I was having an issue with a new LCD and inverter. The backlight
>>still wasnt functioning. Then someone told me about the "toggle
>>switch" that turns the backlight on or off when the lid is opened and
>>closed. Supposed to be near the keyboard. Maybe it has a short or
>>isn't functioning.
>
>
> My manual claims that my Gateway MX6124 notebook turns the screen off
> when I close the lid (they say to conserve battery power). But it
> doesn't (even on battery power). Although it does allow the power
> options to be set where it will go into Standby or Hibernation. I
> currently have it set to do nothing when I close the lid. So while the
> manual is correct for if you use H or S, it is incorrect if you want the
> notebook still running.
>
> I would love to be able to turn off the backlight. As my notebook is on
> almost 24/7 and some of the time I don't need the backlight. And closing
> the lid only causes the laptop to get much warmer while it is running
> (this notebook does run very cool though, which is nice). I can dim it,
> but not turn it off easily. And I'm not convinced that dimming actually
> extends the life of the tube and inverter anyway.
>
> So the only way I know how to turn off the lamp is by adjusting the
> power scheme in the Power Options Properties. PIA to go in there and
> change it for 1 minute though every time I want the lamp off. The plus
> side is that it turns off my extended monitor as well.
>

Barry Watzman wrote:
> Dimming will definitely extend the life of the lamp. The life of the
> inverter isn't really a function of how much it's used. It's a solid
> state electronic device. It will fail, at some point, or it might
> last 3 or more decades without ever failing, but in either case the
> extent of it's use isn't necessarily a factor in how long it lasts.
>
> On most laptops, if you activate the lid closed switch without turning
> the laptop off, yes, the lamp shuts down, but the laptop also begins
> beeping ... this is considered an error condition. It might be more
> effective, as you have done, to just set the settings in power
> management to shut down the screen after a relatively short period of
> inactivity.

Well Barry, believe it or not, I worked for Philips and along with
others like Honeywell, Westinghouse, etc. And believe it or not, solid
state devices do wear out. What effects them are the heating and cooling
cycles for one. As the layers tend to crack if it has been done too
much. And we worked hard to improve this, but it still happens.

And the other thing is we learned quickly in outer space, is that
electrons moving through conducting material, actually moves atoms with
the path of electron flow. This also happens here down on Earth as well,
but far slower. But we humans are getting better and better at
manufacturing this stuff, so it is indeed getting better.

Oh and I tried having the monitors turn off automatically with no
activity last night. And that didn't work. Some program would turn the
monitors back on again in like 10 minutes and then off again in a
minutes and it kept repeating. I just installed TinySpell the other day,
so maybe that is causing it. lol

--
Bill

BillW50 wrote:
> Barry Watzman wrote:
>> Dimming will definitely extend the life of the lamp. The life of the
>> inverter isn't really a function of how much it's used. It's a solid
>> state electronic device. It will fail, at some point, or it might
>> last 3 or more decades without ever failing, but in either case the
>> extent of it's use isn't necessarily a factor in how long it lasts.
>>
>> On most laptops, if you activate the lid closed switch without
>> turning the laptop off, yes, the lamp shuts down, but the laptop
>> also begins beeping ... this is considered an error condition. It
>> might be more effective, as you have done, to just set the settings
>> in power management to shut down the screen after a relatively short
>> period of inactivity.

Another thing to consider Barry is that laptops use what are called
"Cold Cathode Fluorescent Lamps". Which have a normal lifetime of over
25,000 hours. Which is about 10 years of 24/7 if I remember correctly.
See specs like:

http://www.maxim-ic.com/appnotes.cfm...te_number/3528

But fluorescent lamps don't take kindly to being turned on and off a
lot. Besides the lamp doesn't like it, but also the driver (what you
call inverters) has to kick up like 50% higher voltage just to start up
the lamp. This is hard on both the lamp and the driver (inverter). Thus
why either one is very likely to die during one of its startup
procedures.

--
Bill

In message <45217fae$0$1352$> , BillW50
<> writes
>BillW50 wrote:
>> Barry Watzman wrote:
>>> Dimming will definitely extend the life of the lamp. The life of the
>>> inverter isn't really a function of how much it's used. It's a solid
>>> state electronic device. It will fail, at some point, or it might
>>> last 3 or more decades without ever failing, but in either case the
>>> extent of it's use isn't necessarily a factor in how long it lasts.
>>>
>>> On most laptops, if you activate the lid closed switch without
>>> turning the laptop off, yes, the lamp shuts down, but the laptop
>>> also begins beeping ... this is considered an error condition. It
>>> might be more effective, as you have done, to just set the settings
>>> in power management to shut down the screen after a relatively short
>>> period of inactivity.
>
>Another thing to consider Barry is that laptops use what are called
>"Cold Cathode Fluorescent Lamps". Which have a normal lifetime of over
>25,000 hours. Which is about 10 years of 24/7 if I remember correctly.
>See specs like:
>

Assuming 24/7 then

24 hours x 365 days = 8760 hours per year

25,000 hours / 8760 hours per year = 2.85 years

according to my maths!



>http://www.maxim-ic.com/appnotes.cfm...te_number/3528
>
>But fluorescent lamps don't take kindly to being turned on and off a
>lot. Besides the lamp doesn't like it, but also the driver (what you
>call inverters) has to kick up like 50% higher voltage just to start up
>the lamp. This is hard on both the lamp and the driver (inverter). Thus
>why either one is very likely to die during one of its startup
>procedures.
>

--
Nospam

Nospam wrote:
> In message <45217fae$0$1352$> , BillW50
> <> writes
>> BillW50 wrote:
>> Another thing to consider Barry is that laptops use what are called
>> "Cold Cathode Fluorescent Lamps". Which have a normal lifetime of
>> over 25,000 hours. Which is about 10 years of 24/7 if I remember
>> correctly. See specs like:
>>
>> http://www.maxim-ic.com/appnotes.cfm...te_number/3528
>
> Assuming 24/7 then
>
> 24 hours x 365 days = 8760 hours per year
>
> 25,000 hours / 8760 hours per year = 2.85 years
>
> according to my maths!

Oh thanks, I had 2500 hours per year stuck in my head. That figure must
be from 8 hours per day, 5 days per week. Thanks for catching this. And
the lifetime hours figure is generally when the lamp only produces 50%
of its brightness. Here is a neat FAQ that I found that may answer of
some questions someone may have about "Cold Cathode Fluorescent Lamps".

http://www.lcdl.com/faq_terms.html

--
Bill

"BillW50" <> wrote in message
news:45217fae$0$1352$. com...
> BillW50 wrote:
>> Barry Watzman wrote:
>>> Dimming will definitely extend the life of the lamp. The life of the
>>> inverter isn't really a function of how much it's used. It's a solid
>>> state electronic device. It will fail, at some point, or it might
>>> last 3 or more decades without ever failing, but in either case the
>>> extent of it's use isn't necessarily a factor in how long it lasts.
>>>
>>> On most laptops, if you activate the lid closed switch without
>>> turning the laptop off, yes, the lamp shuts down, but the laptop
>>> also begins beeping ... this is considered an error condition. It
>>> might be more effective, as you have done, to just set the settings
>>> in power management to shut down the screen after a relatively short
>>> period of inactivity.
>
> Another thing to consider Barry is that laptops use what are called "Cold
> Cathode Fluorescent Lamps". Which have a normal lifetime of over 25,000
> hours. Which is about 10 years of 24/7 if I remember correctly. See specs
> like:
>
> http://www.maxim-ic.com/appnotes.cfm...te_number/3528
>

That life is only attainable if you strike the lamp and never turn it off.
Hardly a practical guide. The more likely life where the lamp is turned on
and off is closer to an average of 10,000 hours (which is what most panel
manufacturers quote).

The term "Cold Cathode" merely refers to the fact that the cathode is not
independantly heated. The cathode is anything but cold when the lamp is
running. In fact if you take hold of a running lamp, you will have the
outline of the lamp burnt into your hand for quite a while - something a hot
cathode flourescent lamp doesn't do.

It's just like the claimed 8000 hour life of low energy light bulbs. You
might get this if you never turn it off, but 1000 to 1500 hours is nearer
the mark for a bulb in regular service. The small size of the heated
cathode loses a drastic amount of life every time the bulb is struck.

"M.I.5¾" <_SPAM.co.uk> wrote in message
news:45224a1b$
> That life is only attainable if you strike the lamp and never turn it
> off. Hardly a practical guide. The more likely life where the lamp
> is turned on and off is closer to an average of 10,000 hours (which
> is what most panel manufacturers quote).
>
> The term "Cold Cathode" merely refers to the fact that the cathode is
> not independantly heated. The cathode is anything but cold when the
> lamp is running. In fact if you take hold of a running lamp, you
> will have the outline of the lamp burnt into your hand for quite a
> while - something a hot cathode flourescent lamp doesn't do.
>
> It's just like the claimed 8000 hour life of low energy light bulbs.
> You might get this if you never turn it off, but 1000 to 1500 hours
> is nearer the mark for a bulb in regular service. The small size of
> the heated cathode loses a drastic amount of life every time the bulb
> is struck.

Oh I think the hours given are usually off and on a few times per day.
As I have some florescent lamps that say 5000 - 8000 hours and they are
turned on about 10 hours per day and they are coming up to 2 years old
now. They are said to last 5 years, so we will see. Plus they must be up
to the 5000 hour claim by now.

I also experimented with one florescent bulb that was used for like 30
seconds at a time and maybe like turn on and off about 20 times per day.
The one lasted about a year and probably didn't even have 100 total
hours on it. So turning on and off a lot does eat up the lifetime
greatly.

Oh yeah cold cathode does get hot. lol

I think the record of the longest lasting incandescent bulb is one at a
fire station in Livermore, California. It was installed on June 8, 1901.
Last I heard, it is still lit. And to make a bulb last 4000 times longer
is to run them at half voltage. I have 2 in series (so each one gets
half of the voltage) and they have been burning for 20 years now.

--
Bill

In message <45218f07$0$1350$> , BillW50
<> writes
>Nospam wrote:
>> In message <45217fae$0$1352$> , BillW50
>> <> writes
>>> BillW50 wrote:
>>> Another thing to consider Barry is that laptops use what are called
>>> "Cold Cathode Fluorescent Lamps". Which have a normal lifetime of
>>> over 25,000 hours. Which is about 10 years of 24/7 if I remember
>>> correctly. See specs like:
>>>
>>> http://www.maxim-ic.com/appnotes.cfm...te_number/3528
>>
>> Assuming 24/7 then
>>
>> 24 hours x 365 days = 8760 hours per year
>>
>> 25,000 hours / 8760 hours per year = 2.85 years
>>
>> according to my maths!
>
>Oh thanks, I had 2500 hours per year stuck in my head. That figure must
>be from 8 hours per day, 5 days per week. Thanks for catching this. And
>the lifetime hours figure is generally when the lamp only produces 50%
>of its brightness. Here is a neat FAQ that I found that may answer of
>some questions someone may have about "Cold Cathode Fluorescent Lamps".
>
>http://www.lcdl.com/faq_terms.html
>

I have to say;

we, in UK, are constantly being told to switch light off even if you
leave the room for just a few minutes. Save the environment!

I cant help thinking that the constant power cycling that lamps get is
reducing their life span, thus making us buy more lamps, hence adding to
the global warming and not reducing it.

I have no statistics to back this up...

but I can't help wondering if it's not a false economy.

Just a thought

RANT OVER...

back to my day job

--
Nospam

"BillW50" <> wrote in message
news:4522af5b$0$1353$. com...
> "M.I.5¾" <_SPAM.co.uk> wrote in message
> news:45224a1b$
>> That life is only attainable if you strike the lamp and never turn it
>> off. Hardly a practical guide. The more likely life where the lamp
>> is turned on and off is closer to an average of 10,000 hours (which
>> is what most panel manufacturers quote).
>>
>> The term "Cold Cathode" merely refers to the fact that the cathode is
>> not independantly heated. The cathode is anything but cold when the
>> lamp is running. In fact if you take hold of a running lamp, you
>> will have the outline of the lamp burnt into your hand for quite a
>> while - something a hot cathode flourescent lamp doesn't do.
>>
>> It's just like the claimed 8000 hour life of low energy light bulbs. You
>> might get this if you never turn it off, but 1000 to 1500 hours
>> is nearer the mark for a bulb in regular service. The small size of
>> the heated cathode loses a drastic amount of life every time the bulb
>> is struck.
>
> Oh I think the hours given are usually off and on a few times per day. As
> I have some florescent lamps that say 5000 - 8000 hours and they are
> turned on about 10 hours per day and they are coming up to 2 years old
> now. They are said to last 5 years, so we will see. Plus they must be up
> to the 5000 hour claim by now.
>
> I also experimented with one florescent bulb that was used for like 30
> seconds at a time and maybe like turn on and off about 20 times per day.
> The one lasted about a year and probably didn't even have 100 total hours
> on it. So turning on and off a lot does eat up the lifetime greatly.
>

Indeed, and the method of starting has a big influence as well.

> Oh yeah cold cathode does get hot. lol
>

In fact many so called cold cathode tubes are in fact hot cathode. The give
away is the number of wires that come out of the ends. Two wires at each
end and it is in fact a hot cathode.

> I think the record of the longest lasting incandescent bulb is one at a
> fire station in Livermore, California. It was installed on June 8, 1901.
> Last I heard, it is still lit. And to make a bulb last 4000 times longer
> is to run them at half voltage. I have 2 in series (so each one gets half
> of the voltage) and they have been burning for 20 years now.
>

The acepted rule of thumb is that a 10% reduction in operating voltage
doubles the life of the lamp. Halving the voltage turns a nominally 1000
hour lifed bulb into almost a 100,000 hour lifed bulb. You won't get an
awful lot of light from it though. You might now get some appreciation of
how these 5000 hour bulbs that are sold work.