Abstract: The invention relates to a control circuit for a direct current motor with a reverse pole protection device, which is connected to the electric circuit of the electrolytic capacitor and the free-wheeling diode in order to reduce losses in the reverse pole protection device.

Abstract: A system for protecting a power semiconductor output stage that, as a function of a control signal, connects an inductive load to a direct-current supply voltage and disconnects it therefrom. Protection from the induced voltages is achieved, without a freewheeling diode, in that the disconnection energy occurring at the inductive load upon disconnection can be transferred in transformer fashion to an additional inductance that is loaded with a resistance or is coupled in the countercurrent direction to the direct-current supply voltage.

Abstract: A device for position determination in a sensorless direct current motor has a plurality of inductivities arranged in corresponding phases and inducing alternating voltages in a motor windings, a plurality of resistances located in phase branches to be evaluated for a position determination of a rotor position of the sensorless direct current motor, and a plurality of comparator components each associated with the corresponding phase branch to be evaluated.

Abstract: A method of controlling an electronically commutated DC motor having a multiphase stator winding which has an even number m of winding phases which are each connected in series with a controllable semiconductor switch, parallel to one another, in which in a lower power output range of the DC motor the semiconductor switches are cycled using a pulse control factor which is predefinable as a function of the rpm within the consecutive periods when the individual winding phases are energized. To reduce the maximum power losses in the semiconductor switches, a setpoint pulse control factor required for a setpoint rpm is achieved within a selected setting range of the pulse control factor by alternatingly setting a comparatively greater pulse control factor and a comparatively lower pulse control factor, and the setting of the two pulse control factors is varied over time so that a voltage setting the setpoint rpm is set across the stator winding on the average over time.

Abstract: A smart credit card programmed to recognize a single signature for any applicable activities. Using the information in U.S. Pat. No. 5,9911,442 (Yamada) Dec. 23, 1999 and U.S. Pat. No. 6,009,082 (Caswell) Dec. 29, 1999 on pattern recognition and beginning with U.S. Pat. No. 3,962,679 (Engebrecht) on speed recognition in the handwriting, additional programming for four other parts of the writing will be utilized.

Abstract: A method of controlling an electronically commutated DC motor (10) having a multiphase stator winding (11) which has an even number m of winding phases (111-114) which are each connected in series with a controllable semiconductor switch (12), parallel to one another, in which in a lower power output range of the DC motor (10) the semiconductor switches (12) are cycled using a pulse control factor which is predefinable as a function of the rpm within the consecutive periods when the individual winding phases (111-114) are energized.

Abstract: A system and method for interfacing with a nuclear power plant's digital plant protection system activates emergency response devices when necessary. Two redundant bistable processors in each of four logic channels determine whether a particular parameter of the plant operation exceeds safety limits based on output from the plant protection system which monitors plant operations. Two independent coincidence processors in each channel compare the output of each bistable processor with the complementary output of a bistable processor of another logic channel. The results are provided to a series of component control system processors for activating emergency response devices when necessary. A fiber optic network interconnects the logic channels. Within each channel, a fiber optic network is provided between the component control system processors and a main control room so that a manual activation signal can be sent to the component control processors.

Abstract: A device for position determination in a sensorless direct current motor has a plurality of inductivities arranged in corresponding phases and inducing alternating voltages in a motor windings, a plurality of resistances located in phase branches to be evaluated for a position determination of a rotor position of the sensorless direct current motor, and a plurality of comparitor components each associated with the corresponding phase branch to be evaluated.

Abstract: A circuit for operating an electric motor (11) includes a monitoring arrangement (24) for ascertaining an increased load state of the electric motor (11). The monitoring arrangement (24) compares an rpm difference (ND) between a predetermined nominal rpm value (NSOLL) and an actual rpm value signal (NIST) with a predetermined limit value. If the limit value is exceeded, the monitoring arrangement (24) emits an overload signal (25) that reduces the nominal rpm value (NSOLL) or a control variable (SN) supplied to a drive stage (18), or drops it to zero. The circuit is particularly suited for use with a fan, in which instance the ventilator (22) cools the electric motor (11) and/or the drive stage (18).

Abstract: An electric circuit for determining the load current of a clocked load having at least one inductive component and being assigned a free-wheeling circuit has a shunt whose voltage drop is used to determine the current. The shunt is arranged in the free-wheeling circuit to determine the free-wheeling current which is used as a measure for determining the load current (motor current). Furthermore, according to another embodiments the shunt is in series with the load and the free-wheeling circuit is arranged in parallel to the series connection of load and shunt.

Abstract: A process and circuit arrangement are disclosed for determining the speed of a direct current motor (10). The motor data influencing the speed (n) of the motor (10) depend on the operating state of the motor (10), and this dependence is compensated during operation the direct current motor (10) operation during determination of the speed (n).

Abstract: A control device for operating a wiper motor (10) which utilizes the typical path of the wiper motor current (Im) with cyclically recurring minima during the detection of an overload of the wiper motor (10) caused by blockage or tightness of the wiper. During this process, a storage element (C) that integrates the motor current (Im) is short-circuited at least twice within a wiping cycle (Tw) during normal operation so that the transfer of the admissible overload from a half of a wiping cycle (Tw/2) to the following half of the wiping cycle (Tw/2) is prevented and the limit value (G) for the shut-down of the wiper motor (10) is not reached through accumulation of the admissible overload.

Abstract: A circuit for operating an electric motor includes a feedback arrangement which generates a control variable signal that is supplied to a drive stage for the motor. The circuit also includes a monitoring arrangement to ascertain whether the motor is overloaded. The monitoring arrangement emits an overload signal if it detects an overload state, and the control variable signal is then reduced. In one embodiment, the monitoring arrangement detects an overload state by comparing a motor voltage signal to a motor voltage limit value which is a function of the motor current, and emits the overload signal if the motor voltage signal is smaller than the motor voltage limit value.

Abstract: Compounds of the formula ##STR1## in which R.sub.1 is hydrogen or lower alkyl, R.sub.2 is hydrogen or a hydroxyl protective group R.sub.2 ' and R.sub.3 is substituted or unsubstituted phenyl or lower alkyl can be prepared in a three-stage process from readily accessible .beta.-lactam starting materials.