[dorkbotpdx-blabber] controlling lots of ac lines at once ...

Mykle Hansen mykle at mykle.com
Sun Mar 15 12:45:59 EDT 2009

hi all, n00bmaster M here again with more questions about electrons.

i am looking at the possibility of making a pixel display out of
individual cells of el-panel on a flexible substrate.  i haven't
seen this done.  maybe the reason why i haven't seen it done is
because i would need one triac or solid-state relay per pixel,
and those don't seem to be as tiny as everything else in

so i wonder: what's a good strategy for flipping on and off a grid
of something like 20x10 electroluminescent panels?  recall that
these are lit up by a low-current supply of AC at something like
200 volts and 1000 hertz.  the electroluminescent stuff appears
as a capacitive load, so AC flows right through.

i know i could make low-voltage AC by pulsing the DC at 1000hz,
but i'm trying to figure out how to do this without 200 separate
boost converters, or 200 separate SSRs, or 200 separate triacs.

i could use a similar trick to what you'd do with a grid of LEDs,
using a row of X triacs and a row of Y triacs, only i don't know
if that will get the panels bright enough.  if i have ten rows
to scan, then the power is off for 90% of the time, unless there's
some way to turn those square pulses back into sine waves inside of
the matrix somehow.

HELP!  A Bear is Eating Me!

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