Abstract: An electronic ballast for a gas discharge lamp has a power source section for receiving a commercial AC to provide a DC voltage, and an inverter section, in response to a pair of switching driving signals, for switching and transforming an output voltage of the power source section at a high speed as an AC power source that is supplied to the gas discharge lamp. For controlling the switching of the inverter section, an inverter controlling section generates a pair of switching driving signals respectively having a predetermined dead time in a switching-ON time interval with a phase difference of 180 degrees from each other to supply them to the inverter section.

Abstract: Disclosed herein is a structural member comprising an elongated hollow thin metal shell and a filler moulded into the hollow thin metal shell. A reinforcing end piece is engaged with an end portion of the shell and is embedded in the filler in order to prevent the end portion of the shell from deforming in the process of injecting the filler into the shell and to prevent the end portions of the structural member from rupturing or breaking during transportation or construction thereof. In addition, the reinforcing end piece includes an inner wall in contact with an inner surface of the end portion of the shell, an outer wall spaced from the inner wall and in contact with an outer surface of the end portion, and a recessed portion provided between the inner and the outer walls for receiving the end portion of the shell.

Abstract: A structural member comprises an elongated hollow thin metal shell and a concrete filler moulded into the hollow thin metal shell. A pair of reinforcing end pieces is engaged in both ends of the shell and is embedded in the concrete filler in order to prevent both ends of the shell from deforming in the process of injecting concrete mortar into the shell and to prevent both end portions of the structural member from rupturing or breaking during transportation or construction thereof.