| 摘要 |
A mains power loss indicator comprises a permanent wall-mountable housing (10) containing at least two terminals (20, 22) connectable to mains power leads within the wall (12). The housing (10) also contains a rechargeable battery (B1) which is charged up by the mains during periods of mains power and a first lamp (LED1) for emitting light through a window (26) in the housing (10) to provide exterior illumination. A control circuit automatically applies battery (B1) power to the lamp in the case of a loss of mains power. The control circuit also detects at least one failure mode of the battery (B1), and a second lamp (LED2) is illuminated in the case of a battery (B1) failure detected by the control circuit. The second lamp (LED2) is positioned to emit light through the same window (26) as the first lamp (LED1). |
