| 摘要 |
<p>A method and apparatus for actuating a train horn use the speed of the train to determine when to start a horn sequence such that the horn sequence complies with all applicable regulations. In one embodiment, an engineer enters a command, such as by pushing a button, when a predetermined distance from a grade crossing is reached. A processor then determines the speed of the train from a tachometer. The speed is used to determine how long it will take to reach the grade crossing. Preferably, this calculation is repeated until the time to reach the grade crossing is within a window during which the horn sequence must be started. The processor or other device then causes the horn to sound in the required pattern.</p> |
