brightness detector / wall-mounted / outdoor / commercial
The sun/twilight sensor is attached to the window-pane. It measures the light intensity and if, for example, the sunlight is too strong, will lower the blinds. How far the blinds are lowered will depend on the position of the sensor on the window-pane. When normal daylight conditions are restored the blind will rise again. The sensor also causes the blind to be lowered again once it becomes dark outside.