| 摘要 |
PURPOSE:To make it possible to detect an open coil by means of a simply constituted drive circuit for stepping motors, suitable for use in electronic- controlled suspensions. CONSTITUTION:This drive circuit for stepping motors consists of a phase A exciting circuit 8 that excites a coil LA of a stepping motor 3; a phase A exciting circuit 9 that excites a coil LA' of the same; CPU 2 that freely controls the timing of exciting the coils La, LA'; and an overcurrent detecting circuit 6 that detects a current exceeding a specified value through the coils LA, LA'. The drive circuit rotates and drives the stepping motor 3 by alternately exciting the coils LA, LA'. It simultaneously excites the coils LA, LA' according to the control timing provided by the CPU 2. Further, the CPU 2 judges that either one of the coils LA, LA' is open if a current of a specified value or above is not detected based on the detection signal from the overcurrent detecting circuit 6. |
