| 摘要 |
PURPOSE:Commericial power supply and batteries are used as power supply and two guiding lights are installed side by side. At normal times, they are lndicating two directions to two emergency exits. When a fire breaks out, the guiding light whichindicates the direction of the source of fire is extinguished and only guiding light which indicates the direction that is away from the source of the fire is lighted, so that the proper evacuation direction can be indicated for guidance of evacuating people. |
