| 摘要 |
A traffic control device in which a solid state light source such as a light emitting diode (LED) is energized by a power supply such as a battery pack contained within the device. The battery life and conspicuousness of the device are enhanced by providing a network which includes an oscillator circuit and a photocell for intermittently energizing the LED only when the intensity of the ambient light is below a predetermined level. In a preferred embodiment, a plurality of LED's are sequentially energized to enable directional control. |
