Ultrasonic Proximity Sensor (CB21312E)

This circuit was found in a Popular Electronics from the 90s. The circuit uses a ceramic capsule as an emitter and detector.

Sequential Earthworm (CB18227E)
The name of this effect obtained in a 1985 documentation is due to the way the lamps light up in...
Mixer (CB26099E)
We found this 4-channel mixer in the August 1999 issue of Electronics Now magazine. The circuit can...
Operational Wien Bridge Oscillator from 1.5 to 16 kHz (CB12425E)
Found in a 1995 Hands On-Electronics, this circuit generates a sinusoidal signal whose frequency...