초록 ▼

A motor driving apparatus which makes it possible to continue a suppressed power supply to an electric motor even when a detected value (Id) of a current flowing to an H-bridge circuit indicates abnormality, to thereby prevent occurrence of shock in a system in which the motor is employed as a drive

A motor driving apparatus which makes it possible to continue a suppressed power supply to an electric motor even when a detected value (Id) of a current flowing to an H-bridge circuit indicates abnormality, to thereby prevent occurrence of shock in a system in which the motor is employed as a drive source. The apparatus includes a current detecting device (12) for detecting an electric current (I) flowing to an H-bridge circuit (1), and a control device (20) which includes an abnormality decision device (24) for determining abnormality of the detected current value (Id) outputted from the current detecting device (12). When the detected current value (Id) indicates abnormality, both of the ones (Q1; Q4) of the transistors (Q1; Q2 and Q3; Q4) inserted at the side of the power supply source (3) and the ground (GND), respectively, are driven under the PWM control.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for driving an electric motor, comprising:a plurality of transistors constituting an H-bridge circuit, said H-bridge circuit comprising a first plurality of transistors at a first end side and a second plurality of transistors at a second end side thereof, wh

[ What is claimed is:] [1.] An apparatus for driving an electric motor, comprising:a plurality of transistors constituting an H-bridge circuit, said H-bridge circuit comprising a first plurality of transistors at a first end side and a second plurality of transistors at a second end side thereof, wherein output terminals are defined between said first plurality and second plurality of transistors;a power supply source connected to said first end of said H-bridge circuit;a relay inserted between said first end of said H-bridge circuit and said power supply source;a ground connected to said second end of said H-bridge circuit;a plurality of driving circuits for applying either one of a pulse-width modulated signal or a turn-on signal selectively to each of said transistors;control means for controlling on/off operation of said relay and each of said driving circuits;wherein said control means is operative in a first operating mode to turn off one of said first plurality of transistors at the first end side connected to said power supply source and one of said second plurality of transistors at the second end side connected to said ground and to drive other of said first plurality of transistors at the first end side connected to said power supply source and other of said second plurality of transistors at the second end side connected to said ground under pulse-width modulation control or in an on state;for thereby driving an electric motor connected between said output terminals of said H-bridge circuit;said motor driving apparatus further comprising:a current detecting circuit for detecting an electric current flowing to said H-bridge circuit;wherein said control means comprises abnormality decision means for determining an abnormality of a detected current value outputted from said current detecting circuit; andwherein, when said abnormality decision means determines the existence of an abnormality on the basis of said detected current value, said control means is operative in a second operating mode to concurrently drive both said other of said first plurality of transistors and said other of said second plurality of transistors under the pulse-width modulation control, while maintaining off said one of said first plurality of transistors and said one of said second plurality of transistors.