a Telephone dialer (CB10147E)

This circuit was found in an 80s documentation. The integrated circuit used is from that time, being a component that is difficult to obtain today.

| Clique na imagem para ampliar |

Hall current monitor (CB7384E)
Found in an EDN from the 90's this circuit makes use of unusual components today. | Clique na...
Keyboard Encoder (CB25054E)
This circuit was found in the July 1987 issue of Radio Electronics magazine. It uses CMOS...
Digital Voltmeter (CB18686E)
This circuit found in a documentation of the 90s, uses integrated common at the time, but...