Signal lamps and apparatus

Abstract

An LED signal lamp comprises at least two separate LED arrays which have separate power feeds and wherein the LEDs of the arrays are positioned with respect to each other such that when lit they provide a composite light signal output and such that when the LEDs of only one of the two arrays are lit they provide a light signal with a visible distinctive pattern. A distinctive pattern is revealed, either lit or dark. Typically this pattern may be formed as a letter such as 'X' or 'F' or may be formed as a striped effect, for example. An LED signal apparatus comprises input signal power supply terminalsfor the apparatus; a series connection of switch means Sto Sand a ballast loadconnected across the supply terminals; an LED signal lampconnected to the terminals to be supplied with current therefrom; and switch operating means Dto D, in the supply path to the LED lamp, for controlling the state of the switch means Sto Sin the series connection, whereby total failure or substantially total failure of the current to the LED signal lamp results in said switch operating means Dto Dcausing said switch means to open to disconnect the ballast loadfrom power from the supply terminals