This bargraph circuit was found in the January 1986 issue of Radio Electronics magazine. It is based on the well-known LM3914 and has two of them in cascade driving a good number of LEDs.
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...