homebrew vactrols

[Martin Czech]

I can see no advantage of using quanta with different wavelength.
If a quantum has enough energy h*f and it comes the right way,
it will generate a hole-electron pair (ahh, again, positive charge!).

The curves tell that even red quanta have sufficient energy.

The number of carriers will depend on the number of quanta.
There are no "red" electrons or "green" that you would miss
if using only one colour. 
If the intensity is right, you'll get into saturation, i.e.
recombination and to many remaining valence electrons
make it impossible to get lower resistance.

Using a different color then would not help, you can't get lower.
Using a different color before saturation would generate additional
carriers according to the total performance for that wavelength
(encapsulation, passivation etc etc).

As Rene found, a nice orange/red LED should do. No need to add
other colors.

m.c.

:::X-Sender: pfperry at popa.melbpc.org.au
:::Date: Mon, 17 Apr 2000 22:31:45 +1000
:::To: synth-diy at node12b53.a2000.nl
:::From: Paul Perry <pfperry at melbpc.org.au>
:::Subject: Re: homebrew vactrols
:::
:::I wonder whether a mixture of say red & green
:::can make a LDR reach a lower resistance than 
:::an equal amount of only one color?
:::Any solid state physicists here?
:::
:::paul perry melbourne australia