Drive arrangement

摘要

A drive arrangement (1) for driving a motor (9) in a seat belt pre-tensioner incorporates a power supply circuit (6) in the form of an H bridge and a voltage boost circuit 16 which are controlled by a control unit (17). The control unit (17) controls the voltage boost circuit (16) to increase the voltage output to the motor (9) to speed up the rotation of the motor (9) whilst the motor (9) winds in slack in a seat belt (13).