4093 Sine Square Converter (CB26335E)

Found in a Popular Electronics from the 90s, this circuit operates up to about 5 MHz input.

Switching for EMG (CB7373E)
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...
Voltage to Current Converter (CB5100E)
This circuit, which appears from other sources on this site, converts a voltage into a current....
Perpetual Movement (CB14788E)
This interesting circuit makes the needle of a microammeter oscillate at random, imitating a...