AVR-Chat

I don't know, my life is pretty simple already :-)

  I just checked out their site.
  Unless I missed something obvious,  coolneon.com sells el wire and some 
el wire sequencers. Not quite what I'm trying to do.

   I want to use about 96 EL segments to display data, not look phat at a 
rave or burning man.

  But thanks,

-carl

At 03:55 PM 11/29/2004, you wrote:


>I assume you're familiar with the folks at Cool Neon  (coolneon.com).
>Your life will be simplified by about a factor of 10.
>
>Ken
>
>
> >
> > Hi Folks,
> > A little off topic (but we'll still have one of our favorite MCUs driving
> > the mess)
> >   I want to drive a rather large array of electro-luminescent segments. 4
> > to 8 "chars" with about 16 segments each "char".
> >   EL displays need to be driven by a high voltage ac signal in the 100-200
> > volt 100hz-8khz range, current is very low.
> >   Trying for the simplest, cheapest, and  preferably smd approach (I doubt
> > these will be achievable).
> >   I'm not real experienced with the hv ac design of the problem, and just
> > want to bounce a couple of schemes off the list.
> >
> > I can see a couple of ways right off the line. (after some googling)
> >
> >   First,
> >    I make an hv ac power supply swinging +/- 100 volts around ground, use
> > triacs to select segments, and I THINK I can also use triacs to select
> > digits. I believe triacs would drive okay from the avr, should not need
> > isolation.  But, I can't find triacs in packages smaller then to-92. Would
> > like sot-23 package. Suppose I could mount the to-92 as smd.
> >    Power supply would have to be true ac to be sure triacs would turn off
> > by themselves.
> >
> >   Second,
> >   Make a DC hv power supply about 100vdc. Use a couple of mosfets to
> > switch
> > segments between hv, ground, or hi-z. Ditto for digit select. Reversing
> > drive will supply the ac signal requuired at about 200 volts potential to
> > selected segment. Something like an  h-bridge. I like this better because
> > I
> > can adjust the drive freq. / dutycycle in firmware and get brightness
> > control. But, I have no idea how to configure  / interface the fets to
> > avr.  Seems like more parts, but more control over the parts.
> >    Power supply design would be simpler.
> >
> > Whatever happens I'll probably be using shift registers to expand the avr
> > output pins.
> >
> >   Anybody hit this one before?
> >   Thanks
> >   -carl
> >
> >