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Re: About LEDs and LCDs

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On 10/09/2017 01:58 PM, Jan Panteltje wrote:
> My lab power supply display slowly turned black during the last few month...:
>   http://panteltje.com/pub/LCD_turning_black_IMG_6329.JPG
> 
> It is an old design and OK after all those years, but why does this process happen?
> I once had an LCD watch and when sitting in the sun outside all of the sudden it turned black..
> was very hot, bought a new one.
> This thing has not been hot.
> 
> So, anyways had some other ones that did not fit, had a different driver, did not want to re-write the software, thing is way too good,
> so ebay: found a Geeetech Yellow backlight LCD 1602 16x2 Characters display that claimed to have the same driver chip,
> and same mechanical outline, start bid was 99 cents, so I did and got it, shipping 1 dollar.
> Installed it yesterday.
> Works perfectly, OR???
> WOW such a bright backlight, blinding, switched it off again.
> Checked the datasheet, maybe it needed a series resistor ??
> Nope, 5V on the LED pins, resistor is on the module.
> Still could not believe it, looked like a reading light, measured the current:
> 10 mA
> 
> Now you guys talk about LED aging, but it seems the newer ones are so good, those need attenuation.
> Added 270 Ohm in series, now it is OK.
> It is still bright in the evening, but no eye damage this way.
> 
> For new designs I only use OLED.
> 

The display module looks a lot like these I have in my bin (though I 
think they're 1 line):

<https://www.dropbox.com/s/73estagp6emqpfv/Photo%20Oct%2009%2C%204%2020%2034%20PM.jpg?dl=0>

<https://www.dropbox.com/s/pzgvqxzo3ivhu2j/Photo%20Oct%2009%2C%204%2020%2044%20PM.jpg?dl=0>

No backlight, just silver reflective tape on the reverse; it can be 
pulled off and there are terminals on the PCB and room to slide a strip 
of EL material underneath.

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About LEDs and LCDs Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-09 17:58 +0000
  Re: About LEDs and LCDs John Larkin <jjlarkin@highland_snip_technology.com> - 2017-10-09 11:20 -0700
    Re: About LEDs and LCDs Klaus Kragelund <klauskvik@hotmail.com> - 2017-10-09 11:42 -0700
      Re: About LEDs and LCDs Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2017-10-09 19:24 +0000
        Re: About LEDs and LCDs klaus.kragelund@gmail.com - 2017-10-09 13:13 -0700
    Re: About LEDs and LCDs Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-09 19:08 +0000
  Re: About LEDs and LCDs bitrex <bitrex@de.lete.earthlink.net> - 2017-10-09 16:28 -0400
    Re: About LEDs and LCDs Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-10 08:16 +0000
    Re: About LEDs and LCDs Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-10 08:16 +0000
      Re: About LEDs and LCDs bitrex <bitrex@de.lete.earthlink.net> - 2017-10-10 08:06 -0400
        Re: About LEDs and LCDs Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2017-10-10 15:08 +0000
          Re: About LEDs and LCDs Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2017-10-10 15:13 +0000
            Re: About LEDs and LCDs Allan Herriman <allanherriman@hotmail.com> - 2017-10-10 23:21 +0000
          Re: About LEDs and LCDs Clifford Heath <no.spam@please.net> - 2017-10-11 10:58 +1100
            Re: About LEDs and LCDs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-10-10 17:10 -0700
            Re: About LEDs and LCDs Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2017-10-11 14:40 +0000
              Re: About LEDs and LCDs jack4747@gmail.com - 2017-10-11 07:45 -0700
                Re: About LEDs and LCDs Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-11 15:02 +0000
              Re: About LEDs and LCDs krw@notreal.com - 2017-10-11 21:03 -0400
                Re: About LEDs and LCDs Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-12 07:19 +0000
                Re: About LEDs and LCDs rickman <gnuarm@gmail.com> - 2017-10-12 13:07 -0400
                Re: About LEDs and LCDs Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-12 17:18 +0000
                Re: About LEDs and LCDs kevin93 <kevin@whitedigs.com> - 2017-10-12 19:30 -0700
                Re: About LEDs and LCDs krw@notreal.com - 2017-10-12 21:28 -0400
                Re: About LEDs and LCDs krw@notreal.com - 2017-10-12 20:55 -0400
              Re: About LEDs and LCDs Jasen Betts <jasen@xnet.co.nz> - 2017-10-12 04:22 +0000
          Re: About LEDs and LCDs Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-10-10 17:12 -0700
            Re: About LEDs and LCDs Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-11 14:41 +0000
  Re: About LEDs and LCDs Martin Brown <'''newspam'''@nezumi.demon.co.uk> - 2017-10-10 14:56 +0100
    Re: About LEDs and LCDs Jan Panteltje <pNaonStpealmtje@yahoo.com> - 2017-10-10 14:20 +0000

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