Patent ID: 6900595

Claim:
An illumination unit, comprising: a) a lamp; b) contacts for connecting the unit to a main electricity network via an external switch that in turn connects or disconnects a feeding of electricity to at least one of the contacts, wherein the switch, being located somewhere along electricity feeding lines, is located externally of a casing of the illumination unit and is generally remote from the illumination unit; c) a rechargeable element power supply for supplying electrical power to said lamp whenever said switch is in its conductive state and said electricity network fails to supply electricity; and d) an electronic circuit for automatically detecting a state of said switch and failure of said electricity network, said electronic circuit being operative to: d.1) connect said lamp to said rechargeable element power supply only when failure is detected in said electricity network and said external switch is found to be in its conductive state; and d.2) disconnect said lamp from said rechargeable element power supply if said external switch is found to be in its nonconductive state.