A linear actuator (1) comprises a spindle nut arranged to be moved between two end positions on a spindle driven by a DC motor (2). An end stop switch (31) is arranged to be activated when the spindle nut is in an end position. In its activated state, the end stop switch disconnects the motor current and connects a first diode (33) across the DC motor for short circuiting the motor when the current is interrupted. A second diode (32) is connected over the end stop switch for enabling the DC motor to drive the spindle nut out of said end position. An additional component (43) in series with the first diode reduces noise problems caused by motor current circulating through this diode during pulse pauses while the spindle nut is driven out of an end position by a pulse width modulated voltage via a cable from a control box.

Method (100) for controlling a drive arrangement (200) for an automatic door operator (30) of an entrance system (10) having one or more movable door members (D1 . . . Dm), whereby the automatic door operator (30) is for causing movements of the one or more movable door members (D1 . . . Dm) between a closed position and an opened position, respectively. The drive arrangement (200) comprises a DC-motor (34) for driving the automatic door operator (30), a H-bridge (96) and a controller (32, 232) for controlling the drive arrangement (200). The H-bridge (96) comprises a first leg (A) and a second leg (B), the first leg (A) and second leg (B) both being connected to a first voltage supply line (97) and a second voltage supply line (98), the first voltage supply line (97) having a higher voltage than the second voltage supply line (98).

A motor driving circuit includes a first motor driving circuit that controls driving of a first motor is disposed, a second motor driving circuit that controls driving of a second motor is disposed, and a constant current generation circuit that generates a constant current is disposed, and the constant current generation circuit is disposed at a position deviating from between the first motor driving circuit and the second motor driving circuit.

A semiconductor circuit according to the present embodiment comprises a driving circuit, a determining circuit, and a control circuit. The driving circuit includes a first switching element, a second switching element, a third switching element, and a fourth switching element. The comparing circuit compares a potential of the one terminal of the load or a potential of the other terminal of the load. The determining circuit determines, based on output of the comparing circuit, either one or both of a state of the load and a state of the driving circuit. The control circuit controls the driving circuit.

A current limit protecting system and method of a motor pre-driver are provided. A current limiting circuit detects a current of a resistor that is connected to a motor, and then compares the current of the resistor with a current threshold to output a current comparing signal. When a controller circuit determines that the current of the resistor is larger than the current threshold according to the current comparing signal, and a working period of a first signal of a first node or a working period of a second signal of a second node of the motor reaches a preset value, a first high-side switch and a second high-side switch are turned off, and a first low-side switch and a second low-side switch are alternately turned on. As a result, a temperature of the motor generally reduces.

A drive controller includes a first drive circuit, a first capacitance element and a first processing part and a second processing part. The first drive circuit supplies a current output from a power source to a first load. The first capacitance element is connected to a power supply path between the power source and the first drive circuit. The first processing part is configured to apply a charge from the power source and to charge the first capacitance element before power supply to the first load is started. The second processing part is configured to supply a current output from the power source and a current corresponding to a charge charged in the first capacitance element to the first load through the first drive circuit after the first capacitance element is charged.

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The drive system includes an actuation member. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system includes an H-bridge circuit electrically couplable to the electric motor. The control system is configured to control the electric motor based on a sensed parameter associated with the electric motor, a position of the actuation member and a velocity of the actuation member.

A motor drive unit for driving a motor of a motorized window treatment may comprise software-based and hardware-based implementations of a process for detecting and resolving a stall condition in the motor, where the hardware-based implementation is configured to reduce power delivered to the motor if the software-based implementation has not first reduced the power to the motor. A control circuit may detect a stall condition of the motor, and reduce the power delivered to the motor after a first period of time from first detecting the stall condition. The motor drive unit may comprise a stall prevention circuit configured to reduce the power delivered to the motor after a second period of time (e.g., longer than the first period of time) from determining that a rotational sensing circuit is not generating a sensor signal while the control circuit is generating a drive signal to rotate the motor.

Disclosed is a method for at least partially removing the oscillations occurring at the end of a current discharge through the structural diodes for a switching structure supplying power to an inductive load in the form of an H-bridge and including two controlled high or low power switches forming part of a high circuit or a low circuit, respectively, between a respective output and a power source or a ground, the switching structure having one of its outputs below the ground potential and the other above the potential of the power source during the current discharge through the structural diodes. A detection or anticipation of the end of discharge and a forced preservation of a freewheel after the detection of the end of discharge are carried out, the forced preservation of the freewheel after the detection of the end of discharge taking place for a predetermined preservation time.

A method for controlling a semiconductor bridge of an electrically operable motor, the semiconductor bridge being controlled depending on a pulse width modulation signal by a first controllable semiconductor switch and a separate second controllable semiconductor switch for supplying the electrically operable motor with electrical energy, a ramp signal with a predeterminable ramp slope for controlling one of the two controllable semiconductor switches being generated by a ramp generator, depending on the pulse width modulation signal. The invention also relates to a control device and to an arrangement.