| 摘要 |
PROBLEM TO BE SOLVED: To obtain a drive control apparatus by which a temperature rise is suppressed when the driving device of a motor in an overload operation. SOLUTION: On the basis of the opening of an accelerator and on the basis of the speed of rotation of a motor, a forced-operation discrimination circuit 17 discriminates whether the motor is at present in a forced operation (an overload operation) or not. A switch 16 is changed over to the side of a reference clock A14 in an ordinary operation, and a triangular-wave-carrier generation circuit 18 generates triangular waves on the basis of a high-frequency clock signal. Accordingly, a drive control signal which is outputted to a driving device (a power switching element) from a comparator 19 is normally at a high frequency. When it is discriminated by the forced-operation discrimination circuit 17 that the motor us in the forced operation, the switch 16 is changed over to a reference clock B15, and the drive control signal is at a low frequency. As a result the switching loss of the driving device (the power switching element) is reduced. |
