| 摘要 |
A vehicle warning system is provided having a plurality of light emitting diodes mounted on a rearward facing portion of a housing, that may be attached to the side of the vehicle. A switching transistor selectively supplies current to the LED's, through a flashing circuit. The base of the transistor is driven by electrical connection to the junction of first and second phototransistors, which are mounted on the housing and directed skywardly and rearwardly, respectively. During the day the skywardly pointing phototransistor grounds the base of the transistor so that the LED's remain off. At night, the LED's are turned on responsive to the headlights of an oncoming vehicle, which will activate the rearwardly facing phototransistor.
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