This circuit was found in an ancient American documentation. With it is possible to double the frequency of a transmitter For the range of 6 meters obtaining 8 W. The circuit makes use of varicap.
This circuit uses two operational amplifiers, which can be of the type 741, in a full wave...
This circuit converts video signals to digital form in frequency | Clique na imagem para ampliar...
This circuit triggers a relay when the phone rings. An application is like remote doorbell. The circuit...