Abstract: Driving system and method for an electronically commutated multi-speed motor having a coiled stator and a rotor with at least one permanent magnet and having an electronic circuit that feeds voltage to the coils (1, 2, 3) of the stator according to a relative rotor position as sensed by a sensor mounted to the motor shaft, or by interpreting the voltages induced to the stator coils by the moving rotor. A voltage is supplied to an inverter circuit (10) whose output is applied to motor stator coils (1, 2, 3). The voltage applied to the inverter circuit is varied, making use of a speed switching circuit that can include a voltage multiplier or a voltage divider circuit and the variation of the inverter output voltage varies the motor speed.

Abstract: Control circuit for a refrigerating system, used in hermetic compressors, comprising first and second temperature sensors (61,62) and a current sensor (63) for the current drawn by the motor, said control circuit including a central processing unit (30), which instructs at least the selective closing of first and second driving switches (40,50), which are respectively connected with a main winding (11) and with a starting winding (12) of an electric motor (10), when the first temperature sensor (61) detects a temperature inside the refrigerating cabinet corresponding to a maximum value of an ideal temperature interval, previously informed to the central processing unit (30), the temperature of the motor (10) and the current drawn by said motor (10) being within their respective ideal operative values, previously informed to said central processing unit (30).

Abstract: A starting device for a single phase induction motor, of the type having a cage type rotor and a stator having at least one main coil and one starting coil, which is connected in series with first and second terminals of an alternating current source. The starting device comprises a relay (RL) having at least one contact, with one of the terminals thereof being connected to the first terminal (1) of the alternating current source (F), while the other terminal of said contact is connected to the terminal of the starting coil (L2); and a coil (B) for actuating the relay; an electronic timer circuit (T), which is connected to the terminals of the coil (B) for actuating the relay (RL), in order to open the contact of the latter by supplying a current to the coil (B) thereof, thereby finishing the starting operation of the motor (M), after a period of time has elapsed from the motor (M) powering up.

Abstract: An electronic circuit for starting a single phase induction motor operating from a source of alternating current, the motor having a cage type rotor, a coiled stator having at least a main winding and a starting winding, and a permanent capacitor connected in series with the starting winding. The permanent capacitor and the starting winding are connected in parallel to the alternating current source and the main winding in series. A TRIAC has a first terminal connected to one side of the alternating current source and a second terminal connected to the starting winding and to the permanent capacitor. A TRIAC trigger circuit is connected between the TRIAC second terminal and its GATE terminal and a bilateral swtich is connected to the TRIAC GATE terminal.

Abstract: A method and electronic circuit for controlling a brushless direct current motor, the motor having stator coils and a rotor with permanent magnets, in which the rotor position is detected by induced voltages. A control circuit has an inverter for supplying current (I.sub.1, I.sub.2, I.sub.3) to the stator coils (1, 2, 3); a circuit detecting the relative position of the rotor-stator from the induced voltages; and a control circuit processing information (I.sub.m) of current being supplied by the inverter to the stator coils, reference speed (W.sub.ref) and on rotor position (P.sub.1, P.sub.2, PP.sub.3) by sending control signals (S1 to S6) to the inverter. The control circuit comprises a main logic circuit or digital memory, delay elements connected in series, a circuit controlling the supply of current to the motor, a circuit detecting the minimum speed limit of the motor, a circuit for converting the frequency/voltage, a voltage comparator circuit and a Proportional-Integral-Derivative circuit.

Abstract: An electronic control circuit for brushless direct current motor, of the type having a coiled stator and a permanent magnet rotor, with an inverter circuit (10) feeding current to stator coils (21, 22, 23). A rotor-stator relative position detecting circuit (30) and a central controller (70) processes current information fed by the inverter (10), on the reference speed and the relative rotor-stator position, and sends command signals to inverter (10). The detecting circuit (30) has low pass filters (1, 2, 3) connected to terminals (.0..sub.1, .0..sub.2, .0..sub.3) for supplying current to the motor coils, and with the output (F.sub.1, F.sub.2, F.sub.3) of each low pass filter being connected to the noninverting input of a corresponding voltage comparator (59, 60, 61) through a capacitor (56). The inverting input (M.sub.1, M.sub.2, M.sub.

Abstract: Blocking valve for refrigeration or air conditioning systems, of the type which includes: a hermetic compressor driven by an electric motor, a condenser, an evaporator, a capillary tube between the condenser and the evaporator, and a blocking valve between the condenser and the capillary tube. The blocking valve has a housing (42) defining an inside chamber with inlet and outlet passage in fluid communication with the condenser (31) and, respectively, with the capillary tube (32). A magnetic slide (41) installed in the chamber can be displaced between an opening position and a closure position of the valve. Electromagnetic elements (46, 47) assembled in the housing (42) are selectively and automatically energized during a period of time sufficient to cause the displacement of the slide (41) from one operating position to another in accordance with an operating condition of the system, the slide (41) being retained in its operating positions by action of non-electromagnetic forces.