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Re: Acctim alarm clock
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Graham.
Jan 3, 2016, 6:51:45 PM1/3/16
to
On Sun, 03 Jan 2016 21:05:05 +0000, Chris Hogg <m...@privacy.net> wrote:
>I've recently inherited an Acctim 71243 radio controlled alarm clock
>like this one http://tinyurl.com/jczxgkg . But it's display is
>absurdly dim, even in a darkened room. Reading on the Internet, I see
>it has a blue plasma LED display, but dimness of the display seems a
>common complaint with this model. I bought it for my late mother some
>years ago, and I'm sure it used to be brighter, although never
>brilliant. I read (https://en.wikipedia.org/wiki/Plasma_display )
>"Earlier generation displays (circa 2006 and prior) had phosphors that
>lost luminosity over time, resulting in gradual decline of absolute
>image brightness".
>
>Is there any way I can get into the works and increase the brightness,
>or is it doomed? I suspect the latter!
That's a backlit LCD display, not an LED.
"Plasma" would suggest the back-light isn't LED either, probebly a
cold cathode tube or similar.
--
Graham.
%Profound_observation%
>I've recently inherited an Acctim 71243 radio controlled alarm clock
>like this one http://tinyurl.com/jczxgkg . But it's display is
>absurdly dim, even in a darkened room. Reading on the Internet, I see
>it has a blue plasma LED display, but dimness of the display seems a
>common complaint with this model. I bought it for my late mother some
>years ago, and I'm sure it used to be brighter, although never
>brilliant. I read (https://en.wikipedia.org/wiki/Plasma_display )
>"Earlier generation displays (circa 2006 and prior) had phosphors that
>lost luminosity over time, resulting in gradual decline of absolute
>image brightness".
>
>Is there any way I can get into the works and increase the brightness,
>or is it doomed? I suspect the latter!
That's a backlit LCD display, not an LED.
"Plasma" would suggest the back-light isn't LED either, probebly a
cold cathode tube or similar.
--
Graham.
%Profound_observation%
Dave Liquorice
Jan 3, 2016, 9:13:10 PM1/3/16
to
On Sun, 03 Jan 2016 23:51:34 +0000, Graham. wrote:
>> Is there any way I can get into the works and increase the
brightness,
>> or is it doomed? I suspect the latter!
>
> That's a backlit LCD display, not an LED.
How can you tell from that image?
>> Is there any way I can get into the works and increase the
brightness,
>> or is it doomed? I suspect the latter!
>
> That's a backlit LCD display, not an LED.
> "Plasma" would suggest the back-light isn't LED either, probebly a
> cold cathode tube or similar.
LCD, or LED.
https://www.noritake-elec.com/display/vfd_operation.html
VFD's do age, as the phosphor "wears out". It might be possible to
get some brightness back by raising the filament voltage.
--
Cheers
Dave.
Brian-Gaff
Jan 4, 2016, 3:08:44 AM1/4/16
to
Well doomed I fancy. After all its actual changes in the phosphor.
I have a scanner radio with similar issues. Not that it bothers me any
more but in order to make it bright enough I increased the brightness by
changing a resistor inside which was changed to control brightness. The only
snag of doing this was a bit of ghostly glow from nearby segments of the
display, which I guess is some kind of leakage effect that not allowing the
full brightness fixed.
I have a pink and blue display on a dab radio which is losing brightness
apparently as well, though I have no idea what technology it is using.
Brian
--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"Chris Hogg" <m...@privacy.net> wrote in message
news:fl1j8b1ct68m8vh5i...@4ax.com...
>
> Chris
I have a scanner radio with similar issues. Not that it bothers me any
more but in order to make it bright enough I increased the brightness by
changing a resistor inside which was changed to control brightness. The only
snag of doing this was a bit of ghostly glow from nearby segments of the
display, which I guess is some kind of leakage effect that not allowing the
full brightness fixed.
I have a pink and blue display on a dab radio which is losing brightness
apparently as well, though I have no idea what technology it is using.
Brian
--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"Chris Hogg" <m...@privacy.net> wrote in message
news:fl1j8b1ct68m8vh5i...@4ax.com...
> I've recently inherited an Acctim 71243 radio controlled alarm clock
> like this one http://tinyurl.com/jczxgkg . But it's display is
> absurdly dim, even in a darkened room. Reading on the Internet, I see
> it has a blue plasma LED display, but dimness of the display seems a
> common complaint with this model. I bought it for my late mother some
> years ago, and I'm sure it used to be brighter, although never
> brilliant. I read (https://en.wikipedia.org/wiki/Plasma_display )
> "Earlier generation displays (circa 2006 and prior) had phosphors that
> lost luminosity over time, resulting in gradual decline of absolute
> image brightness".
>
> like this one http://tinyurl.com/jczxgkg . But it's display is
> absurdly dim, even in a darkened room. Reading on the Internet, I see
> it has a blue plasma LED display, but dimness of the display seems a
> common complaint with this model. I bought it for my late mother some
> years ago, and I'm sure it used to be brighter, although never
> brilliant. I read (https://en.wikipedia.org/wiki/Plasma_display )
> "Earlier generation displays (circa 2006 and prior) had phosphors that
> lost luminosity over time, resulting in gradual decline of absolute
> image brightness".
>
> Is there any way I can get into the works and increase the brightness,
> or is it doomed? I suspect the latter!
>
> --
> or is it doomed? I suspect the latter!
>
>
> Chris
Brian-Gaff
Jan 4, 2016, 3:11:29 AM1/4/16
to
The ones I'm thinking of are glass units with pins along one edge, and
obvious segments inside that would appear to be like little tubes of gas
with phosphor on them. If you tap them they actually go ding, not that helps
in any way!
Brian
--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
"Graham." <graham...@mail.com> wrote in message
news:bpcj8bt9lhjctc32g...@4ax.com...
obvious segments inside that would appear to be like little tubes of gas
with phosphor on them. If you tap them they actually go ding, not that helps
in any way!
Brian
--
From the Sofa of Brian Gaff Reply address is active
Remember, if you don't like where I post
or what I say, you don't have to
read my posts! :-)
news:bpcj8bt9lhjctc32g...@4ax.com...
Graham.
Jan 4, 2016, 5:05:34 AM1/4/16
to
manual that described it as an LCD, but I see now it wasn't a 71243.
They probebly reckoned that "Plasma LED" would sell better than VFD,
and what's more they could argue it's not a lie, as each segment is a
(thermionic) diode and it emits light!
--
Graham.
%Profound_observation%
Dave Plowman (News)
Jan 4, 2016, 6:16:41 AM1/4/16
to
In article <fddk8bl622pch1gna...@4ax.com>,
Chris Hogg <m...@privacy.net> wrote:
> Thanks for the replies. I am confused (as usual and yet again!). The
> Amazon link says Plasma LED, but it wouldn't surprise me if whoever
> wrote the advert had got it wrong, and you and Graham have differing
> opinions.
Plasma displays were common before LEDs got bright enough for daytime use.
The OBC on my 30 year old Rover SD1 has one. That still works just fine -
but of course won't have had the same hours of use as a clock.
--
*Real men don't waste their hormones growing hair
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Chris Hogg <m...@privacy.net> wrote:
> Thanks for the replies. I am confused (as usual and yet again!). The
> Amazon link says Plasma LED, but it wouldn't surprise me if whoever
> wrote the advert had got it wrong, and you and Graham have differing
> opinions.
Plasma displays were common before LEDs got bright enough for daytime use.
The OBC on my 30 year old Rover SD1 has one. That still works just fine -
but of course won't have had the same hours of use as a clock.
--
*Real men don't waste their hormones growing hair
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
Harry Bloomfield
Jan 4, 2016, 9:50:52 AM1/4/16
to
Chris Hogg was thinking very hard :
> FWIW, the clock has battery back-up so that it continues to receive
> the MSF Anthorn signal and doesn't lose time when the mains is off.
> When in battery mode, the display is nominally switched off, but you
> can see the display numbers if you hold the clock at the right angle,
> silvery ghosts against a black background, and showing the correct
> time. There's no way of momentarily turning on back-light
I know exactly the type of back light you mean, I have similar with the
same dimness issue on an old Tandy/Realistic scanning receiver. It uses
a film technology, inserted behind LCD and all suffer the same issue.
You can get replacements, which can be carefully cut to size, but is it
worth it. The best fix is to add some high brightness tiny LED's along
the edge of the display, if you can.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
> FWIW, the clock has battery back-up so that it continues to receive
> the MSF Anthorn signal and doesn't lose time when the mains is off.
> When in battery mode, the display is nominally switched off, but you
> can see the display numbers if you hold the clock at the right angle,
> silvery ghosts against a black background, and showing the correct
> time. There's no way of momentarily turning on back-light
I know exactly the type of back light you mean, I have similar with the
same dimness issue on an old Tandy/Realistic scanning receiver. It uses
a film technology, inserted behind LCD and all suffer the same issue.
You can get replacements, which can be carefully cut to size, but is it
worth it. The best fix is to add some high brightness tiny LED's along
the edge of the display, if you can.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
Dave Liquorice
Jan 4, 2016, 12:13:05 PM1/4/16
to
On Mon, 04 Jan 2016 09:37:27 +0000, Chris Hogg wrote:
> Does any of that help in deciding their technology? AIUI, the polaroid
> effect suggests some sort of LCD. But do plasma displays also use
> polarised light?
Not unless they have polarised filter in front of them but they don't
need it. Also I wouldn't expect to see ghosts of the actual changing
time on a VFD display with the clock in backup mode.
I'll switch my money to LCD. B-)
--
Cheers
Dave.
> Does any of that help in deciding their technology? AIUI, the polaroid
> effect suggests some sort of LCD. But do plasma displays also use
> polarised light?
Not unless they have polarised filter in front of them but they don't
need it. Also I wouldn't expect to see ghosts of the actual changing
time on a VFD display with the clock in backup mode.
I'll switch my money to LCD. B-)
--
Cheers
Dave.
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