A wireless terminal is associated with a Basic Service Set or an Independent Basic Service Set. To this end, the high frequency power may be increased at a higher rate compared to the low frequency power component, wherein, additionally, a time delay may be applied so that, at any rate, the high frequency component reaches its target power level prior to the low frequency component. A negative side arm unit includes IGBT modules, a coupling diode module, a cooling plate on which the modules are mounted, and a second laminated bus bar connected to the respective modules, and both the laminated bus bars and the capacitors are connected to one another by a third laminated bus bar. In yet another embodiment, certain features of the modular units are symmetrical relative to a lateral plane to facilitate the joining of the units to one another in different orders. The projector may include a mirror positioned to reflect light from the projector onto the projection board. The one of a cable and a sheet member is capable of being wound over the drum and has one end fixed to the drum and another end acting on the spring for transmitting a driving force of the motor to the spring.