| 摘要 |
PROBLEM TO BE SOLVED: To improve the safety in the case of a malfunction in a system that rotates and drives a motor by sequentially switching the energization phase of a motor, which serves as a drive source for a range switching device.SOLUTION: A bi-wire control circuit 34 stores in advance a table X that prescribes the energization phase address corresponding to each address, and a table Y that prescribes an energization phase corresponding to each energization phase address. When a drive permission code is received, the control circuit 34 computes an address to access the table X on the basis of the drive permission code and the energization phase pattern No. Thereafter, by computing, with reference to the table X, the energization phase address corresponding to this address, an energization phase address for accessing the table Y in correct order is computed. Thereafter by determining, with reference to the table Y, the energization phase corresponding to this energization phase address, the energization phase is switched in correct order that rotates and drives a motor. |
