Abstract: An electric motor for driving a component, such as a vehicle window lifter or a machine tool, functions as a generator, when the motor drive voltage is switched off and the motor is short circuited. The motor keeps running due to inertia or other influences. During this period after switch-off a generator voltage and respective generator current are produced. The generator current is measured for various purposes, preferably in combination with a measured r.p.m. signal. The generator current signal alone, or in combination with the r.p.m. signal, is evaluated to provide information regarding the motion of the driven component including information regarding the motion direction and position of the component.

Abstract: An electric motor for driving a component, such as a vehicle window lifter or a machine tool, functions as a generator, when the motor drive voltage is switched off and the motor is short circuited. The motor keeps running due to inertia or other influences. During this period after switch-off a generator voltage and respective generator current are produced. The generator current is measured for various purposes, preferably in combination with a measured r.p.m. signal. The generator current signal alone, or in combination with the r.p.m. signal, is evaluated to provide information regarding the motion of the driven component including information regarding the motion direction and position of the component.

Abstract: A switching device with a power FET for switching an inductive load to which a free-wheeling diode is connected in parallel, wherein the terminal of the series resistor facing away from the gate terminal is connected to a driver circuit which is so designed that it connects the specified terminal with a reverse potential in order to block the FET, wherein, at the beginning of the process of making the FET conductive, it connects the specified terminal with a high resistance to a control voltage source that puts the FET into the conductive state, in such a way that the current rise of the current flowing through the FET is slowed down to such an extent that, within a period of time in which the free-wheeling diode is not yet blocking after starting to make the FET conductive, an increase of the current to undesirable high values is prevented, so that damage to the power FET and the free-wheeling diode and/or other circuit elements and/or the occurrence of electromagnetic disturbances is reduced, and wherein, a

Abstract: A circuit arrangement protects an FET power switch against damage from short circuits that may occur in the load connected between the drain terminal and an operating voltage source of the FET. The protection is achieved by the cooperation between a shunt resistor (3) connected between ground and the source terminal (S) of the FET and a gate voltage limiter (7) connected to the gate terminal of the FET. This cooperation limits the short circuit current through the FET until a short circuit detector (DT) provides a control signal that switches the FET off.