>  I need something very thin.

There are special-purpose chips aimed at backlighting in wrist-watches.  (H=
uh.  Microchip even has a line; it looks like they must have acquired Super=
tex!  http://www.microchip.com/ParamChartSearch/Chart.aspx?branchID=3D9020 =
)

I experimented with some of these quite some time ago, and discovered that =
they are not really very well matched to EL wire requirements; both voltage=
 and frequency tend to be too low, and total power is low as well (they=92r=
e designed for a square inch or two of EL panel at +/- 80Vp-p and 400Hz, wh=
ile EL Wire would like 2kHz @110Vrms (~300Vp-p))  However, the =93operation=
al description=94 looks like something that would be implementable in discr=
etes.

The usual circuit is a pretty conventional inductor-based boost circuit (an=
d you can get really tiny inductors for watches/etc) to generate high-volta=
ge DC, followed by a HV H-bridge to generate =93AC=94 at a frequency that i=
s independent of the boost circuit switching freq.  At one point, I was thi=
nking that having microprocessor control over the AC frequency was the idea=
l way to control EL brightness, and I designed a circuit and PCB that would=
 let a PIC or AVR do all the work.  But I never got around to actually buil=
ding it, so I couldn=92t say whether it actually works=85

These days there are also some tiny IC aimed at charging caps for Xenon fla=
sh circuits (and extra tiny transformers to go with them.)  That might be a=
nother possibility.

BillW


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