Modulated infrared emitter (CB7251E)

Found in a 1968 Mullard manual, this circuit can function as an infrared audio link. The transistors can be the BC548.

| Clique na imagem para ampliar |

Synchronized astable (CB21832E)
This circuit was taken from the 1974 Ferranti transistor manual. Note the shapes of the signals....
Economic Ambulance Siren (CB18011E)
This mini siren, found in a 2003 publication, powers a small piezoelectric transducer, but a...
Fuzz (CB12093E)
This fuzz effect is from a 1988 Italian publication, but it can be easily assembled, as the...