[sdiy] Spice model for a Vactrol ???

[harrybissell]

Anyone have a good idea for making a spice model
of a Vactrol ???

I'm thinking of calling the LED a current controlled source (of voltage
or
current) but I can't figure out how to make the output look like a
variable
resistance.

Right now I don't care about approximating the actual resistance curve
vs
input current... just want to make it work :^)

H^) harry