公开(公告)号：US20240140356A1

公开(公告)日：2024-05-02

申请号：US18548759

申请日：2022-02-24

Applicant: Autoliv Development AB

Inventor： Philip RINGS ,  Fooke KUTSCHER

IPC: B60R22/343

CPC classification number: B60R22/343 ,  H02M3/04

Abstract: A belt retractor unit with a housing, a belt reel rotatably mounted in this housing, a blocking unit for blocking the belt reel against the housing, wherein the blocking unit has an actuator unit with an electromagnet and a control apparatus for controlling the electromagnet, which has a power input, a power output connected to the electromagnet and at least one signal input for receiving a control signal and/or a sensor unit for generating a control signal, wherein the control apparatus has at least a first active switching state and a passive switching state, wherein in the first active switching state an electric current flows between the power output and the electromagnet, the current intensity of which is greater than in the passive switching state, wherein the control apparatus has between the power input and the power output at least one DC/DC converter acting as a constant current source, so that the current intensity in the first active switching state has a defined first value independent of the voltage applied to the power input.