A multi-layer LED assembly which is used as a replacement light for equipment used in manufacturing environments. On each layer of the multi-layer assembly, there are multiple LEDs which are mounted perpendicular to a base. The base is used to provide electrical and mechanical connection to a socket. The LED assembly is constructed in a manner which allows the LED assembly to be inserted into a socket of a lighting fixture and then mechanical and electrical connections are provided without requiring rotation of the LED assembly. Electrical connection is by permanently attached wires between the base and the LEDs. The base is rotatable within a predetermined angular range which is sufficient to provide a proper mechanical and electrical connection without putting strain on the permanently attached electrical wires. The LED assembly may utilize multiple layers of LEDs, with each layer itself having multiple LEDs. The LEDs in each layer are mounted in a direction perpendicular to the base which results in light emanating in a direction perpendicular to the base.

A panel illuminating module consisting of an array of light-emitting diodes is provided wherein the light from the array can be adjustably directed to a target after the module is installed within the panel. The module has two parts, an upper part carrying the light-emitting diodes, and a lower part which is designed to install into standard panel circuitry connectors. The upper part is attached to the lower part by a cylindrical shaft about which one of the two parts is rotatable. Spring tension normally holds the two parts together on the shaft and a locking pin normally prevents the two parts from rotating relative to one another. However, the two parts can be optionally pulled apart from one another (against the spring tension) to disengage the locking pin and to allow the two parts to rotate relative to one another.

In a lighting fixture such as an exit sign, a mounting base assembly is provided on a light emitting diode lighting device for mating engagement with an electrical socket. Once full mating engagement is achieved between the electrical socket and a base member of the mounting base assembly, the position of the housing carrying the light emitting diodes of the lighting device can be adjusted for alignment purposes without disturbing the full mating engagement of the electrical socket and the base member.

An LED array comprising a substrate, a plurality of first LEDs, and a plurality of second LEDs, wherein the range of wavelengths of light from the first LEDs is different from the range of wavelengths of light from the second LEDs; the first LEDs and the second LEDs are respectively connected in series so that a current alternatively flows through the first LEDs and the second LEDs in the opposite directions; the first LEDs connected in series and the second LEDs connected in series are further connected in parallel; and the first LEDs and second LEDs are arranged in a line on the substrate.

An illuminating module with battery backup consisting of an array of light-emitting diodes is provided wherein the module combines the battery backup with the LED array in a self-contained light bulb-like unit which can be retrofitted into an existing incandescent light bulb socket. The batteries and the LED array are attached to a planar baseboard which further includes two base connectors. The base connectors are adapted to fit into existing light bulb sockets and are rotatably mounted on an edge of the baseboard to enable screwing them into light bulb sockets while the baseboard is kept stationary. The backup batteries are recharged from an external source of electrical current flowing through the base connectors. An automatic switching device switches the supply of electrical power for the LED array from the external source of electrical power to the backup batteries, when the flow of external electrical power is disrupted. A circuit causes the LED array to flash on and off to indicate interruption of external power, to prolong battery life, and to make the module more conspicuous in emergency conditions.