| 摘要 |
<p>An LED signal apparatus comprises input signal power supply terminals (7,8) for the apparatus; a series connection of switch means (S1 to S4) and a ballast load (6) connected across the supply terminals (7,8); an LED signal lamp(1,2) connected to the terminals to be supplied with current therefrom; and switch operating means (D1 to D4), in the supply path to the LED lamp, for controlling the state of the switch means (S 1 to S4) in the series connection, whereby total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means (D to D4) causing said switch means to open to disconnect the ballast load (6) from power from the supply terminals (7,8).</p> |
