| 摘要 |
<p>A real-time speed display apparatus for displaying vehicle speed with different colors of light has a speed detector (21) for detecting the revolution speed of the transmission shaft of a vehicle and outputting a speed signal with its pulse rate varied as a function of the revolution speed. The speed signal is converted into a periodically interval signal through a timing gate (31) under the control of a clock signal generated by a clock generator (32). A counter is used to count the number of the pulses within each period of the interval signal, based on which an encoder (34) outputs a corresponding display control dignal and transmits it to respective display drivers (41). Upon receipt of the display control signal, the drivers (41) are started to drive the respective light units. Therefore, different color light is formed on a screen by combination of light emitted by the driven light units.</p> |
