Abstract: A single piezoelectric is excited at a first frequency to cause two vibration modes in a resonator producing a first elliptical motion in a first direction at a selected contacting portion of the resonator that is placed in frictional engagement with a driven element to move the driven element in a first direction. A second frequency excites the same piezoelectric to cause two vibration modes of the resonator producing a second elliptical motion in a second direction at the selected contacting portion to move the driven element in a second direction. The piezoelectric is preloaded in compression by the resonator. Walls of the resonator are stressed past their yield point to maintain the preload. Specially shaped ends on the piezoelectric help preloading. The piezoelectric can send or receive vibratory signals through the driven element to or from sensors to determine the position of the driven element relative to the piezoelectric element or resonator.

Abstract: A single piezoelectric is excited at a first frequency to cause two vibration modes in a resonator producing a first elliptical motion in a first direction at a selected contacting portion of the resonator that is placed in frictional engagement with a driven element to move the driven element in a first direction. A second frequency excites the same piezoelectric to cause two vibration modes of the resonator producing a second elliptical motion in a second direction at the selected contacting portion to move the driven element in a second direction. The piezoelectric is preloaded in compression by the resonator. Walls of the resonator are stressed past their yield point to maintain the preload. Specially shaped ends on the piezoelectric help preloading. The piezoelectric can send or receive vibratory signals through the driven element to or from sensors to determine the position of the driven element relative to the piezoelectric element or resonator.

Abstract: A sealed connecting device for sealing a motor-pump aggregate includes a brush-holder plate disposed in the sealing plane between the motor housing and the pump housing. A U-shaped sealing ring member is stretched over the outer rim of the brush-holder plate. Connecting leads, which lead to the outside, are embedded free of compression in the brush-holder plate in the sealing fit area and are inserted radially outside of the fit area through sealingly abutting sealing tubes pre-molded on the sealing ring member.

Abstract: A method and a device for recognizing defects in a triggering system of a controlled series compensator. An intervention is made in the closed-loop control of the controlled series compensator on the basis of an impedance differential (.DELTA.Z) determined from a setpoint impedance (Z.sub.S1, Z.sub.S2) and from an effective impedance (Z.sub.i) calculated from system variables (i.sub.L,u.sub.C), and in dependence upon the voltage level of a measured conduction current (i.sub.L). When the conduction currents (i.sub.L) are smaller than a limiting value (i.sub.LG), the firing is blocked in the branches, and when the conduction currents (i.sub.L) are greater than a limiting value (i.sub.LG), a firing-angle signal (S.sub..alpha.S) is generated, through which means the valve (Th1, Th2) can be protectively fired. Thus, one is able to recognize defects in the triggering system of the controlled series compensator by applying system variables (i.sub.L,u.sub.

Abstract: A plant for thermal waste disposal includes a pyrolysis reactor converting waste into carbonization gas and substantially non-volatile pyrolysis residue and a discharge device connected to the pyrolysis reactor. A combustion chamber operated with an oxygen excess is connected to a carbonization gas discharge fitting of the discharge device for receiving the carbonization gas. A residue sorting device is connected to the pyrolysis residue outlet of the discharge device for sorting out coarser coarse components substantially including non-combustible ingredients such as rocks, glass shards, broken porcelain, and metal parts, from combustible finer coarse components. A transport device connected to the residue sorting device transports the finer coarse components. A grinding apparatus has an inlet side connected to the transport device and a discharge side for feeding the finer coarse components to the combustion chamber after grinding.