Abstract: An electronically-commutated DC machine having a permanent magnet rotor, generating a homogeneous magnetic field with linear and radially extending magnetic field lines. The rotor continuously changes polarity within an essentially cylindrical air gap. Meander-like stator means include linear forward and backward extending meander sections within the annular gap. Each linear meander section includes a number of conductor sections arranged geometrically parallel and having an essentially rectangular cross-sectional area. Each conductor section is located within the annular gap so that the longer side of the conductor cross-sectional area extends parallel to the direction of the magnetic field lines. A fan may be provided within the motor housing independently driven by a second stator rotor combination to produce a cooling air flow in the annular gap, cooling the conductor section of the stator means.

Abstract: The rotor of an electronically commutated DC machine, which may be operated in the motor mode or in the generator mode, comprises at least one permanent magnet having at least four poles disposed concentrically to the rotary axis of the rotor, said poles being polarized substantially normal to said axis of rotation and being disposed adjacent an annular return circuit member. The stator winding is arranged in the annular gap between rotor and return circuit members and comprises a meander-like conductive strip array whose linear forward or backward extending meander sections consist of a number of parallel conductor sections. Means for detecting the angular position of the rotor relative to the linear forward and backward extending meander sections supplies signals to an electronic control system which in turn controls the flow of current through the conductive strip array such that the latter produces a magnetic field to drive the rotor.

Abstract: A motor-compressor for a refrigerator includes a housing containing a lubricant and a reciprocating compressor driven by a direct-current electric motor having a disc-shaped rotor and stator. The stator is located between magnetic flux closing discs of the rotor and carries electronically commutated drive coils. Goniometric indicators detect the position of the rotor and cause signals to be applied to an alternating current generator which modulates a bridge circuit to provide current flux for driving the rotor.

Abstract: A control circuit is provided for controlling operation of an electrical or electromechanical system which oscillates at a basic frequency, such as a coil-operated compressor of a vehicle cooling system.The control circuit has a power output stage which feeds operating power to the oscillating system, and a generator which drives the power output stage and is synchronized with the oscillating system.The generator comprises an oscillator which produces a pulse sequence at twice the basic frequency of the oscillating system and a converter which modifies the pulse sequence of the oscillator so that every second pulse fed to the power stage has the same polarity. Feedback from the oscillating system is applied to an input of the oscillator to synchronize the oscillator with the oscillating system.