Abstract: A method for determining a phase angle between voltage applied to a winding of the electric motor and an electric current flowing through the winding may include receiving a signal from the electric motor, including a value of a voltage applied to a winding of the electric motor. The method may also include determining a value of an electric current flowing through the winding and determining a phase angle between the voltage applied to the winding and the electric current flowing through the winding. The method may also include determining a speed or a stall state of the electric motor.

Abstract: A method for determining a phase angle between voltage applied to a winding of the electric motor and an electric current flowing through the winding may include receiving a signal from the electric motor, including a value of a voltage applied to a winding of the electric motor. The method may also include determining a value of an electric current flowing through the winding and determining a phase angle between the voltage applied to the winding and the electric current flowing through the winding. The method may also include determining a speed or a stall state of the electric motor.

Abstract: A circuit for speed monitoring of an electric motor comprises a circuit for generating a time-frame signal, a circuit for receiving a first signal from a chopper driver circuit designed to drive the electric motor, a circuit for detecting chopper pulses in the first signal, a pulse counter, and a circuit for at least one of outputting and evaluating a state of the pulse counter, after the inactive state of the time-frame has been indicated. The time-frame signal indicates when a time-frame of predefined length changes from an inactive state to an active state and indicates when the time-frame changes back from the active state to the inactive state. The pulse counter is designed to count the detected chopper pulses while the active state is indicated by the circuit for generating the time-frame signal.

Abstract: A circuit for speed monitoring of an electric motor comprises a circuit for generating a time-frame signal, a circuit for receiving a first signal from a chopper driver circuit designed to drive the electric motor, a circuit for detecting chopper pulses in the first signal, a pulse counter, and a circuit for at least one of outputting and evaluating a state of the pulse counter, after the inactive state of the time-frame has been indicated. The time-frame signal indicates when a time-frame of predefined length changes from an inactive state to an active state and indicates when the time-frame changes back from the active state to the inactive state. The pulse counter is designed to count the detected chopper pulses while the active state is indicated by the circuit for generating the time-frame signal.