| 摘要 |
A long range identification system is disclosed for utilizing a radio frequency (RF) signal sent by a calling location, such as a mass transit vehicle, as the energy source to power response apparatus at a responding location, such as a route stop of the transit vehicle. The responding signal is then broadcast within the transit vehicle as audio or as a video display of a signal from a character generator, or as both audio and video. The long range identification system includes a RF transmitter at the calling location, a receiver at the responding location for receiving the signal and passively generating RF voltage in response to a particular RF signal of a predetermined frequency, a rectifier, capacitors connected to the rectifier to store charge, a voltage regulator connected to the capacitors and operating when a sufficient charge has developed in the capacitors, a digital code generator identifying the responding location, a transmitter for broadcasting a signal carrying the identifying code, and a receiver and decoder located at the calling location, or elsewhere.
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