| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric seat belt device capable of predicting a regenerative current flowing when an electric motor is regenerated by a simple circuit configuration and reducing manufacturing cost. <P>SOLUTION: This electric seat belt device comprises FET 1 to FET 4 forming an H bridge circuit, flywheel diodes 5-8 connected to the FET 1-FET 4, respectively, the electric motor 9 for winding up a seat belt 21, a motor current detection circuit 12 for outputting the current flowing in the electric motor 9 in the form of a current signal, an MPU 13 for outputting control signals for the electrifying direction and electrifying current amount of the electric motor 9 by the current signal, and a FET drive circuit 14 for driving, by PWM, the FET 1-FET 4 by the control signals. The motor current detection circuit 12 comprises a drive current detection circuit 15 for detecting the drive current flowing in the electric motor 9 when a drive current is supplied from a battery 10 according to the voltages at both ends of a shunt resistor 11 and a regenerative current predicting circuit 16 for predicting, from the drive current, the regenerative current flowing when the electric motor 9 is regenerated. <P>COPYRIGHT: (C)2008,JPO&INPIT |
