Abstract: An emergency lighting system has emergency light units operable by DC power and connected to a source of AC and DC power by the same conduit system. Power to the conduit system may be switched from AC to DC in the event of a power failure and a load relay module in the conduit system adjacent the light units senses the change to DC current and switches from an Ac load output to a DC load output to supply DC power to the emergency light units. The system will generally include both exit signs operable by both AC and DC power and emergency light units operable only by DC power.

Abstract: A LED lamp for use in lighted sign assemblies has a base configured to engage an associated electrical socket, a light array extending from the base, the base has conductive elements on the outer surface thereof to effect a power connection to the socket and internal contacts coupled thereto. The light array consists of three elongated circuit boards extending from the end of the base and oriented with respect to each other to form an array of triangular cross section. Each of the circuit boards has a multiplicity of light emitting diodes mounted upon its outer surface and spaced along its length, and a conductor connected to the diodes. A power transfer circuit electrically connects the circuit board conductor to the contacts in the base to provide electrical power to the diodes, and a generally tubular housing of light transmitting material mounted upon and extending from the end of the base in spaced relationship to the array.