A power tool having an electric motor intended to rotate in a first direction but not in an opposite second direction, comprising: an elongated housing configured to be grasped by a user; an output shaft at least partially contained in the housing; an electric motor residing in the housing and drivably connected to the output shaft to impart rotary motion thereto; a switching arrangement having a plurality of motor switches and interposed between the electric motor and a power source; three position sensors (56, 58, 60), each position sensor (56, 58, 60) configured to detect rotational motion of the electric motor and generate a signal having a periodic waveform whose magnitude varies in accordance with rotational position of the motor; characterised in that there is further provided a first latch circuit configured to receive a first signal from a first one of the position sensors (56, 58, 60) and a second signal from a second one of the position sensors (56, 58, 60) and operates to generate an output state indicative of sequence of magnitude variations in the first signal in relation to magnitude variations in the second signal; a second latch circuit configured to receive the second signal from the second one of the position sensors (56, 58, 60), a third signal from a third one of the position sensors (56, 58, 60) and the output state from the first latch circuit, the second latch circuit operates to generate a shutdown signal in accordance with sequence of magnitude variations in the first latch output signal in relation to magnitude variations in the second and third signals; and a motor driver module interfaced with the motor switches and operable to control switching operation of the motor switches, wherein the motor driver module is configured to receive the shutdown signal from the second latch circuit and discontinue driving the motor in response to the shutdown signal; wherein the first signal serves as a clock signal for the first latch circuit; wherein the first latch circuit generates an output state having a high value in response to the second signal having a high value during a rising edge of the first signal and generates an output state having a low value in response to the second signal having a low value during a rising edge of the first signal; wherein the second signal serves as a clock signal for the second latch circuit; wherein the second latch circuit monitors the sequence of magnitude variations in the second and third signals in response to receiving an output state with a high value from the first latch circuit. wherein the second latch circuit generates the shutdown signal with a high value in response to the third signal having a high value during a rising edge of the second signal. an elongated housing configured to be grasped by a user; an output shaft at least partially contained in the housing; an electric motor residing in the housing and drivably connected to the output shaft to impart rotary motion thereto; a switching arrangement having a plurality of motor switches and interposed between the electric motor and a power source; three position sensors (56, 58, 60), each position sensor (56, 58, 60) configured to detect rotational motion of the electric motor and generate a signal having a periodic waveform whose magnitude varies in accordance with rotational position of the motor; characterised in that there is further provided a first latch circuit configured to receive a first signal from a first one of the position sensors (56, 58, 60) and a second signal from a second one of the position sensors (56, 58, 60) and operates to generate an output state indicative of sequence of magnitude variations in the first signal in relation to magnitude variations in the second signal; a second latch circuit configured to receive the second signal from the second one of the position sensors (56, 58, 60), a third signal from a third one of the position sensors (56, 58, 60) and the output state from the first latch circuit, the second latch circuit operates to generate a shutdown signal in accordance with sequence of magnitude variations in the first latch output signal in relation to magnitude variations in the second and third signals; and a motor driver module interfaced with the motor switches and operable to control switching operation of the motor switches, wherein the motor driver module is configured to receive the shutdown signal from the second latch circuit and discontinue driving the motor in response to the shutdown signal; wherein the first signal serves as a clock signal for the first latch circuit; wherein the first latch circuit generates an output state having a high value in response to the second signal having a high value during a rising edge of the first signal and generates an output state having a low value in response to the second signal having a low value during a rising edge of the first signal; wherein the second signal serves as a clock signal for the second latch circuit; wherein the second latch circuit monitors the sequence of magnitude variations in the second and third signals in response to receiving an output state with a high value from the first latch circuit. wherein the second latch circuit generates the shutdown signal with a high value in response to the third signal having a high value during a rising edge of the second signal.