Found in an 80's Electronic Design, this circuit is based on the ICL7107 which is not an easy component to obtain today. The circuit is compatible with TTL and CMOS.
This circuit uses a Hall device from that time as a sensor. The circuit is from an English...
Found in Radio Electronics from the 90s, this siren finds many variations on this site. The...
This audio generator that produces both rectangular and sinusoidal signals was found in a...