Audio Cable Tester (CB3827E)

This simple circuit tests both monophonic and other two-wire audio cables. The circuit is powered by two common batteries.

Pulse width discriminator (CB9690E)
This circuit was obtained in a 70s American documentation. The integrated circuits of the time are...
Motor photoelectric control (CB8022E)
This circuit was found in a 1964 Electronic Design. The components are from the era and the load...
10-Minute Timer (CB13950E)
This timer, from an old American publication, uses indicator lamps, but can be modified to use...