Crystal oscillator (CB9504E)

This circuit was found in a 90s Popular Electronics. It can generate signals from 3 to 10 MHz.

Operational Fuzz (CB11029E)
This circuit was obtained from Hands-On Electronics, an American magazine of January 1987. The...
Thermometer using thermistor (CB6407E)
This circuit is from a 1965 General Electric Hobby manual. The circuit uses only passive...
Temperature to period converter (CB21594E)
Based on Texas Instruments documentation, this circuit serves for sensor interfacing. The circuit is...