A wind turbine generator includes: a main shaft; a generator having a rotor and a stator; and a sleeve coupled to the rotor and inserted onto the main shaft. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided. The method also includes querying one or more sets of identifiers to determine whether one or more of the requested synchronizations objects specified by the selected request are acquirable. The system is preferably configured to provide low-level night light from the night light when measured light levels and detected motion are below threshold values and to automatically turn on the indoor andor outdoor lighting and simultaneously turn off the night light when measured light levels and detected motion are above the threshold values. Another feature of the etching system includes the ability to accurately determine the end point of the etch step, such as by creating an impedance at the exit of the etching chamber so that when the vapor phase etchant passes from the etching chamber, a gaseous product of the etching reaction is monitored, and the end point of the removal process can be determined. Embodiments also perform frequency up-conversion.