Drive Arrangement

摘要

A drive arrangement (1) comprising an input (2) from a primary power source (5) and an auxiliary power source (7). The drive arrangement (1) incorporates a DC-DC converter (8) and a motor driver circuit (14). The motor driver circuit (14) is connected to a motor (18) in a motorised seat belt retractor. The drive arrangement (1) drives the motor (18) in the event of a crash situation. If the connection between the drive arrangement (1) and the primary power source (5) is lost then the drive arrangement (1) draws power from the auxiliary power source (7) to drive the motor (18). The auxiliary power source (7) can also assist the primary power source (5) by limiting the current drawn from the primary power source (5).

主权项

1. A drive arrangement for driving a motor in a vehicle safety device, the arrangement comprising:
a power supply input configured to be connected to a primary power source, an auxiliary power source, a DC-DC converter circuit configured to operate in at least a voltage boost mode, the DC-DC converter circuit having a DC-DC converter circuit input that is connected to the auxiliary power source, a motor driver circuit having a motor driver circuit input that is connected to an output of the DC-DC converter circuit and to the power supply input, and a control unit connected to the DC-DC converter circuit, the control unit being configured to activate the DC-DC converter circuit to operate in the voltage boost mode to increase the voltage to the motor driver circuit input if the voltage at the motor driver circuit input is below a predetermined level.