In use telephone indicator (CB9297E)

Found in a Popular Electronics from the 90's, this circuit is used to indicate the operation of telephones of the time. The circuit is TTL.

| Clique na imagem para ampliar |

High Current Regulator (CB10982E)
This circuit was obtained in a 1978 English magazine. This adjustable stabilized power source...
Windscreen Wiper Timer (CB4957E)
This circuit was found in old documentation, but as it uses the 555 it can still be easily...
Self timer (CB21579E)
This timer with field effect transistors was obtained from Fairchild documentation. The times...