| 摘要 |
<p>A proportionality is established between the rate of rotation of a wheel and the frequency of a periodic signal, pref. by optical coupling of a light-emitting cell mounted beneath an axle of the vehicle to a photoreceiver attached to the inside face of a wheel. Once during each revolution of the wheel, the emitted light falls upon the photoreceiver and produces a photoelectric current. The linear speed of the vehicle can be deduced from the photocurrent frequency and wheel dia. A selective amplifier can be used to regulate the max. speed. The system provides a measurement of distance travelled, and other applications of this method can be obtained from the production of a periodic electrical signal using a light-emitting cell.</p> |
