A vibration type activator having improved electro-mechanical energy conversion efficiency and reduced noise generation includes plural switching elements each of which is operated by a switching pulse signal generated by a drive control circuit of the motor. In an exemplary embodiment, power limit control of the present invention is broken into two levels of control: a site-wide real power limit control that produces a single site-wide command, SitePlimCom, for all inverters, and inverter-level power limit control that outputs a command, Invx. Overlapping areas of the kernels are displayed in different colors than corresponding non-overlapping areas. The applicator also includes provision for automatic needle retraction after cartridge contents expression. The tray is removably attachable to the rotatable support.