Abstract: The invention relates to a control device for stopping the operation of a single-phase asynchronous motor with a capacitor in the event an overload of this motor with respect to a threshold value is detected. This device is characterized in that it includes, on the one hand, device for measuring the phase shift between any one parameter, voltage or current (U1, U2, I2, I3) of the main phase (.phi.1) or the secondary phase (.phi.2) and another one of these parameters and, on the other hand, device for controlling the stoppage capable of interrupting the current supply to the motor in the event there is measured a time delay lower than a memorized threshold value.

Abstract: The invention relates to a motor-driven roller blind comprising, on the one hand, an apron rolling up onto and unrolling from a winding shaft inside which is accommodated a tubular-type driving gear-motor and, on the other hand, means providing an electrical signal representative of the movement of the apron and an electrical-signal processing unit capable of acting on the running of the driving gear-motor, viz. to control the stopping of same in the event an obstacle is present. As a matter of fact, said means providing an electrical signal representative of the movement of the apron are comprised of at least one inductive sensor extending at least partly along the path followed by the apron, this inductive sensor being capable of creating an electromotive force under the action of the passing of a permanent magnet associated with the lower portion of the apron, which electromotive force is detected by the processing unit.

Abstract: The invention relates to a device for controlling the variation of the power and/or the speed of a load (2), such as an asynchronous, synchronous, universal motor, a transformer, an inductance, a condenser or a resistor, comprising a switch (5) placed on a phase (4) of a single-phase or multiphase alternating-current supply-circuit (3), this switch (5) being associated with means (6) for controlling the cyclic ratio .alpha./T in which .alpha. corresponds to the time of opening and closing of the circuit (3) by the switch (5) and T to the period of the phase (4) on which this latter is placed. In fact, the switch (5) is of the bidirectional MOS, IGBT or bipolar transistor switch type, this switch (5) being associated with means (9) for controlling the switching time, of the DRIVER type, capable of extending the switching time at closing so that it be within a range from 10 microseconds to 1 millisecond.