Based on Allegro's A6275, this circuit controls the brightness of various displays. The circuit is valid for common anode 7-segment displays.
A circuit for controlling the temperature of a heating element was found in a Mullard transistor manual...
We found this circuit in a 1992 Popular Electronics. The circuit has an optical sensor with LED...
I found this circuit in an old English magazine from 1979, but it can be easily assembled with...