| 摘要 |
In accordance with the present invention, a signal generator providing multiple signals with different frequencies includes, in a combined form, a clock (1), an address counter (2), a memory (3), and a digital-to-analog converter (4), which are to be series-connected. Individual storage locations within the memory (3) shall be preloaded with amplitude samples for the entire group of signals with different frequencies, which are to be selected in such a manner that storage locations in use within the aforementioned memory (3) shall contain an integral number of cycles for each signal. The address counter (2), which is controlled by the clock (1), shall successively address each storage location within the memory (3), and a capacitor (5) connected to the converter output shall be used to smooth the resulting signal. Applicable for systems permitting prompt transmission of multiple messages within railway systems, by use of contact ramps. |
