From: RussellMc <apptechnz@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Thu, 22 Jul 2021 05:05:02 -0700
Subject: Re: [EE] EL lamps dimming
Thread-Topic: [EE] EL lamps dimming
Thread-Index: Add+8z/WFtxuxNxGQtq8rtlxcR0eJA==
Message-ID:
 <CACZQxzNUROasqWDEpnu_MKr-h3eC0bkPh4jV+w2HtmAZdC0VQQ@mail.gmail.com>
References: <5e3fa754-7198-9a41-3a9a-203698c65028@narwani.org>
	<SJ0PR02MB7662D48EEC6523B84E382B9DDC119@SJ0PR02MB7662.namprd02.prod.outlook.com>
	<CAN7ULzSqCA09qLn4RByA-DfrgfYX65FJHuVac9-aKG_oxdNTSQ@mail.gmail.com>
	<3c7b9844-7477-059b-d62e-39d1bb681c21@narwani.org>
	<CAN7ULzQV-2GEwbVF8NUi6EgS9WZRiXHmUBjMWaSgat=MdqR+eA@mail.gmail.com>
In-Reply-To:
 <CAN7ULzQV-2GEwbVF8NUi6EgS9WZRiXHmUBjMWaSgat=MdqR+eA@mail.gmail.com>
Reply-To: Microcontroller discussion list - Public. <piclist@mit.edu>
Accept-Language: en-US
X-MS-Exchange-Organization-SenderIdResult: Pass
X-MS-Exchange-Organization-PRD: mit.edu
X-MS-TNEF-Correlator:
received-spf: Pass (protection.outlook.com: domain of gmail.com designates
	209.85.167.45 as permitted sender) receiver=protection.outlook.com;
	client-ip=209.85.167.45; helo=mail-lf1-f45.google.com;
dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com;
 s=20161025;
	h=mime-version:references:in-reply-to:from:date:message-id:subject:to;
 	bh=Z/da+qxBZecSf8htnrrab+WJzmWgxh0iquahMcJPhIA=;
	b=acHwpZqmeL/zas3Xa57qL72kncuA4MlJnQtobxoSH8q9FDI43SBldpLJBkBFem/LZY
	zGt2JJpNCJvRjpNY5hs0isvQ/w9zAea73Ob/Oj9oD28b0475vc9Qz0KCus9HVdXOGNwi
	2nJ/XrNiT6OaPSgIirJKRNvhmH9pv1UKUdHJWIKOTv5b88d2BLHe2LyNaWlZHOPqaJYC
	a+RD5wvFY7ZIwIg10NsFv/uK1OaWAw7EgnxE3PTxWW97P393nly9IyaS8GxYf+V+dxaH
	SQUmj+NkdLpOBqvVEuGc8uJi5iaKT/9JXrJvF/J7olm9tvM1SrsSgskZz9vsoWQDkvBQ	Rm+Q==
authentication-results: spf=pass (sender IP is 209.85.167.45)
	smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified)
	header.d=gmail.com; mit.edu;	dmarc=pass action=none header.from=gmail.com; 
errors-to: piclist-bounces@mit.edu
list-id: "Microcontroller discussion list - Public." <piclist.mit.edu>
list-post: <mailto:piclist@mit.edu>
x-beenthere: piclist@mit.edu
x-mailman-version: 2.1.6
x-received: by 2002:a05:6512:143:: with SMTP id
	m3mr29232856lfo.241.1626955539816; 	Thu, 22 Jul 2021 05:05:39 -0700 (PDT)
x-topics: [EE]
x-content-filtered-by: Mailman/MimeDel 2.1.6
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

On Thu, 22 Jul 2021 at 23:50, Clint Jay <cjaysharp@gmail.com> wrote:

> It is/was an issue, depends on the encapsulation of the EL material, I se=
em
> to remember reading that one or more companies had worked out a way to
> encapsulate it in miniscule glass beads which reduced the problem.
>
> My experience with the flexible panels (Laptop backlights originally and
> then on smaller LCD panels in embedded gear) showed that degradation
> happens with use and age (much like a fluorescent tube) and any damage to
> the plastic film encapsulating the panel would cause rapid degradation du=
e
> to moisture ingress, even if not damaged the thin wires that connected th=
e
> panel to power weren't perfectly sealed or had been damaged by soldering =
so
> panels would degrade from the entry point.
>
> I have a number of plastic encased EL panels about 8" x 3" from memory,
probably over 20 years old.
I could try operating one to see how it behaves.

They used to dim with age - the ones I have were repair spares for a now
long defunct product.


        Russell




> On Thu, 22 Jul 2021 at 04:45, Neil <picdude3@narwani.org> wrote:
>
> > Hmmm... hadn't thought of things like moisture.
> > Sadly, the only fix is a pricey replacement.
> >
> >
> >
> > On 7/17/2021 5:40 AM, Clint Jay wrote:
> > > Hi Neil,  they do age in use, I'm not sure if they age in storage but
> > > moisture absorption used to be a problem.
> > >
> > > On Fri, 16 Jul 2021, 05:10 Bob Blick, <bobblick@outlook.com> wrote:
> > >
> > >> Hi Neil,
> > >> I believe the brightness is more stable when controlled by current,
> so a
> > >> series resistor is probably better than a voltage divider.
> > >> Friendly regards, Bob
> > >>
> > >> ________________________________________
> > >> From: piclist-bounces@mit.edu <piclist-bounces@mit.edu> on behalf of
> > Neil
> > >> <picdude3@narwani.org>
> > >> Sent: Thursday, July 15, 2021 8:14 PM
> > >> To: Microcontroller discussion list - Public.
> > >> Subject: [EE] EL lamps dimming
> > >>
> > >> Hi all,
> > >>
> > >> I'm helping someone build a flight sim from parts of an older
> > >> FAA-certified simulator, and currently working on the EL panels.  I
> have
> > >> 2 questions re: dimming:
> > >>
> > >> First, the older panels are much dimmer than the new panels.  The
> device
> > >> is ~9 years old, but as we understand it, it was in storage for most
> (if
> > >> not all) of that time.  Do EL lamps just go dim over time without us=
e?
> > >> If not, then maybe the device was used quite a bit, or maybe the
> quality
> > >> of the EL panels have just improved over time.
> > >>
> > >> Second, I need to dim the newer panels to match the older ones.  Can=
 I
> > >> do this with a simple voltage divider on the output of the EL
> inverter?
> > >> I have one inverter powering 7 small panels, so I'd have to dim the
> > >> output side to the new panels, or maybe get a second inverter and di=
m
> > >> the input of one of the inverters.
> > >>
> > >> Cheers,
> > >> -Neil.
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.