Thread: Dimming backlight with Illumination wire?

I saw a couple posts where someone had suggested that it could be possible to dim an LCD backlight based on the input from the illumination wire, but never saw anyone actually doing it.

I have a DSCustoms DS700YYV screen which does have an adjustable brightness, so I know dimming is possible. Does anyone have a circut for doing dimming like this?

The design must be: At 0V on illunination wire, set brightness to a predetermined maximum value. At any other voltage between the maximum and minimum seen on your cars illum. wire, set the brightness in between two other predetermined maximum values.

Ie you'd have a small PCB with inverter power in/out, illum in/out, vehicle GND, and three screw-adjustable pots to determine "daylight" (headlights off) brightness, and the min/max brightness for console dimming. This would be really slick in my car where the console lighting adjusts its brightness dynamically depending on the ambient light!

If the adjustable dimming is not possible; how about a circut that just dims to a preset value when voltage is on illum and to another preset value when there is no voltage?