Abstract: A position-controlled actuator includes a motor supplied with power by a power supply circuit controlled at least by an error signal. A speed reducer converts rotary movement of the motor into linear movement over a given travel. An output sensor indicates the position of the actuator and an error signal computation circuit compares a commanded position of the actuator to a calculated position. The output sensor supplies a binary position signal taking two different values according to the position of the actuator relative to its mid-travel position.

Abstract: An actuator suitable for autopilot control of a helicopter tail rotor comprises a direct current motor, a non-reversible gearbox, a speed reducer driving an output shaft, a friction device disposed between the non-reversible gearbox and the speed reducer and a friction exceeded sensing device adapted to cut off the supply of power to the motor.

Abstract: A process is disclosed for converting a bis-(diol) terephthalate to dimethyl terephthalate, by interchange in a methanol medium in the presence of magnesium methylate as catalyst. In this way dimethyl terephthalate may be regenerated from scrap of polyterephthalate or copolyterephthalate filaments or films, for the purpose of manufacturing fresh polyterephthalates or copolyterephthalates which can then be used for the manufacture of, for example, filaments or films.