Micro metronome (CB20743E)

This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light sources.

Magnetic field meter (CB7067E)
Found in an EDN from the 80's, this circuit makes use of an operational one of the time. The...
Telephone Dialer (CB5979E)
This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference,...
3 Volt Switched Regulator LM2577 (CB15410E)
The circuit presented is from the Linear Applications Handbook of the National Semiconductor of...