Tone Oscillator (CB22066E)

Found in old documentation, this oscillator with the LM380 produces an audio tone in a speaker. Frequency is set in VR1.

Ultrasonic repellent (CB20814E)
This sophisticated repellent uses a double 555. We find it in an American documentation from the...
1960 Hybrid Radio (CB21946E)
This circuit was found in a publication by Gernsback. It uses two batteries and in addition to the...
Simple function generator (CB20950E)
Found in Popular Electronics from the 1980s, this circuit uses two operational amplifiers from...