This 9-pixel circuit has been implemented with 9 LDRs and can be coupled to a processing system for an elementary artificial eye. The circuit is from Radio Electronics, November 1986.
This excellent wireless microphone circuit for the varicap-modulated FM band came out in...
The simple low voltage source that can be used as a battery eliminator, shown in the figure was...
This asymmetrical crossover filter was obtained from an 80s integrated circuit manual. The...