| 摘要 |
Signals, such as elements of the Morse code, are produced by projecting a stream of energy, such as a small gas stream or light beam, against the normally obstructing annular zone of a rotating disc provided with apertures which allow the energy to pass through in a controlled pattern. Means mounting the input stream and the transmitter in axial alignment are mounted for selective shifting to other annuli of the disc; in this way a disc can carry a series of different signals. The transmitter may be a simple transducer, such as an air activated pipe, or whistle, or it may be a light conduit leading to a photosensitive transducer. The tone produced stimulates closely the commercial radio and wireless signals and facilitates teaching the code by means of aural rather than visual images.
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