Wien Bridge Oscillator (CB8093E)

This circuit was found in a Popular Electronics from the 90s. Transistors admit equivalents, as well as the operational.

LM3914 with Overscale Alarm (CB25112E)
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
4001 Touch Bistable (CB25740E)
Found in the July 1994 Electronics Now magazine, this circuit drives a relay up to 12 V depending on...
OM13090 Voice Recognition Kit
May 2017 - Mouser Electronics is delivering a voice recognition kit from NXP Semiconductors. The...