| 摘要 |
<p>A portable safety device for attracting visual attention, comprises an array of flashing light sources, comprising high intensity light-emitting diodes having a light output of at least 500 mcandela. The light sources are connected in series with a solid state flashing circuit and a power supply. The power supply comprises a high energy battery and current limiting means in series therewith. The current limiting means prevents the current supplied by the battery externally of the power supply from exceeding a predetermined safe value. The solid state flashing circuit is periodically switchable between a low resistance state characterized in that the voltage across the series arrangement of high intensity light-emitting diodes exceeds a threshold voltage thereof, and a high resistance state characterized in that the voltage across the series arrangement of high intensity light-emitting diodes falls below the threshold voltage. The high intensity light-emitting diodes flash brightly to provide a low current attention-attracting device visible at long range.</p> |
