Astable 555 (CB21101E)

This 50% duty cycle configuration was found in a Popular Electronics from the 1990s. The operating frequency is given by C1.

Model railway alarm (CB22528E)
This circuit detects traffic problems on a miniature railway by triggering an alarm. The circuit was...
Soft Start Regulator (CB15498E)
When establishing the voltage at the input of this regulator, the output voltage rises smoothly until...
JFET Audio Compressor (CB19998E)
This circuit was found in a Motorola documentation from 1975. Modern equivalent transistors such...