Abstract: A supply-voltage discrimination device for adapting a load (8) to a lower or higher alternating-voltage range includes a voltage-dependent resistor (1) thermally coupled to a PTC-resistor (2) and electrically connected in series with said voltage-dependent resistor. The resistors are chosen so that initially the dissipation is mainly determined by the voltage-dependent resistor.

Abstract: A stepping motor with a first and a coaxially disposed second stator section. The stator sections are axially separated by a coaxially disposed permanent-magnetic ring. On the inside, each stator section terminates in two coaxially disposed annular systems of teeth. The systems of teeth of each stator section have been shifted nominally by 1/2 tooth pitch relative to the rotor teeth and the systems situated on the outside relative to the permanent magnetic ring as well as the systems of teeth situated on the inside relative to the permanent magnetic ring exhibit a nominal mutual shift relative to the rotor teeth of 1/4 tooth pitch. Stepping angle errors in this stepping motor can now be eliminated to a high degree by symmetrically correcting the displacement of the outer systems of teeth relative to each other and/or the displacement of the inner systems of teeth relative to each other.

Abstract: A stepping motor having a first and a coaxially disposed second annular stator section, which stator sections are axially spaced by a coaxially disposed permanent-magnetic ring. Each stator section terminates on the inner side in two coaxially disposed annular systems of teeth. The systems of teeth of each stator section have been mutually shifted nominally by 1/2 tooth pitch relative to the rotor toothing and the systems of teeth situated on the outer side relative to the permanent-magnetic ring as well as the systems of teeth situated on the inner side relative to the permanent-magnetic ring exhibit a mutual shift relative to the rotor toothing of nominal 1/4 tooth pitch.

Abstract: An electronically commutating motor having a phase winding connected in at least one of the branches of a bridge circuit. A comparator measures the voltage across one of the diagonals of the bridge and switches the voltage across the other bridge diagonal as a function of the polarity of the first-mentioned voltage.

Abstract: A synchronous motor, in particular a stepping motor, with two coaxial stator sections which are each provided with a ring coil and with two circular systems of teeth, which are shifted by half a tooth pitch relative to each other. The two stator sections are shifted by a quarter tooth pitch relative to each other. In addition, the motor comprises an axially magnetized permanent-magnetic ring which is disposed between the two stator systems, for magnetizing the two systems of teeth of the stator sections with mutually the same polarity. The two systems of teeth of each stator section are constituted by annular parts which are provided with teeth at the inner circumference. The annular parts form part of the magnetic circuit which surrounds the annular coil and are disposed concentrically in such a way that the axial distance between the teeth of both systems is at least a few times greater than the air gap between stator and rotor.