A method for repeated determination of dynamic parameters of an n-phase synchronous motor, in particular of the rotor angle φ and of the rotor frequency ω, by measuring induced motor phase voltages, comprising, in each determination phase, the following steps: - feeding current to the synchronous motor through a sine-commutating trigger circuit; - briefly interrupting the current feed of at least two motor phases of the synchronous motor for a measuring period T M until their magnetic energy has faded in order to measure the motor phase voltages (U U, U V, U w) in said measuring period T M; - measuring the motor phase voltages (U U, U V, U w) in the at least two motor phases of the synchronous motor using an analog measurement amplifier circuit for generating motor phase measuring voltages (U U, U V', U W') at at least one time of measurement t m, the measurement amplifier circuit having an adjustable amplification or attenuation so that a measurement amplification is set in particular as a function of the motor phase voltages (U U, U V, U W) and/or of the previously determined dynamic parameters, and a neutral point of the motor phases being connected to a measuring potential U m = U ref / 2 which is in the middle of the dynamic range U ref of the A/D converter during the interruption of the current feed in the measuring period T M and at least when measuring the motor phase voltages (U U, Uv, U W) at the time of measurement t m; - A/D-converting the analog motor phase measuring voltages (U U', U V', U w') at the time of measurement t m to determine digital measured values (U dU', U dV', U dV') of the motor phase voltages (25, S4); - calculating the dynamic parameters on the basis of the measured digital measured values (U dU', U dV', U dW') of the motor phase voltages using a calculating unit; - connecting the current feed of the synchronous motor to the correct phases. - feeding current to the synchronous motor through a sine-commutating trigger circuit; - briefly interrupting the current feed of at least two motor phases of the synchronous motor for a measuring period T M until their magnetic energy has faded in order to measure the motor phase voltages (U U, U V, U w) in said measuring period T M; - measuring the motor phase voltages (U U, U V, U w) in the at least two motor phases of the synchronous motor using an analog measurement amplifier circuit for generating motor phase measuring voltages (U U, U V', U W') at at least one time of measurement t m, the measurement amplifier circuit having an adjustable amplification or attenuation so that a measurement amplification is set in particular as a function of the motor phase voltages (U U, U V, U W) and/or of the previously determined dynamic parameters, and a neutral point of the motor phases being connected to a measuring potential U m = U ref / 2 which is in the middle of the dynamic range U ref of the A/D converter during the interruption of the current feed in the measuring period T M and at least when measuring the motor phase voltages (U U, Uv, U W) at the time of measurement t m; - A/D-converting the analog motor phase measuring voltages (U U', U V', U w') at the time of measurement t m to determine digital measured values (U dU', U dV', U dV') of the motor phase voltages (25, S4); - calculating the dynamic parameters on the basis of the measured digital measured values (U dU', U dV', U dW') of the motor phase voltages using a calculating unit; - connecting the current feed of the synchronous motor to the correct phases.