Abstract: In a circuit arrangement for influencing the start-up and/or braking behavior of three-phase a.c. non-synchronous motors having phase windings (5, 6, 7), which are connected in star for continuous operation and have terminals for the phase conductors (1, 2, 3) and for a neutral conductor (4) the phase terminal of one phase winding (6, 7) is connected by a change-over switch (9, 11) to the neutral conductor (4) for start-up and/or braking. A corresponding circuit arrangement is disclosed also for three-phase a.c. non-synchronous machines in which the phase windings (5, 6, 7) have terminals for the phase conductors (1, 2, 3) and for a neutral conductor (4).
Abstract: A D.C. motor includes a brush and commutator used in starting the motor, but which are not used during the running cycle of the motor. The rotor is formed of a permanent magnet. The stator includes a pair of opposite pole driving coils arranged 180.degree. from each other. A sensing coil is placed halfway between the two driving coils. A starting coil is also included halfway between the driving coils and directly across from the sensing coil. Brushes are mounted on the rotor which contact the stationary commutator when the motor is at rest or just starting. As the motor speeds up, the brushes are centrifugally removed from the commutator, thus breaking the starting circuit.
Abstract: A transistor chopper for controlling the power delivered to a DC load from a DC source includes two or more transistors connected in series between the DC source and the load and means for controlling the voltage across each transistor so that the transistor is subjected to only a fraction of the open circuit voltage developed by the DC source. Lower power transistors may therefore be used as switching elements in the chopper, and hence the overall cost of the system is reduced over prior choppers.
Abstract: A system for controlling the speed of a direct current motor. The system employs a pair of breaker points for opening and closing the circuit containing the motor. By varying the frequency of contact between the breaker points and the period of time the points are in contact, different pulsations of current are transmitted to the motor to regulate its speed.