| 摘要 |
PROBLEM TO BE SOLVED: To avoid stepping failure in severe vibrations by using the period ratio between a reference value and the pulse of the first flow during the total continuance time as the function of the load level of a motor. SOLUTION: The time reference signal is outputted from an originating device Q and sent into a dividing/shaping circuit 90. In this output, a power supply period TO for a motor, a continuing time T4 of a partial pulse, a continuing time T1 of the first chop pulse, a reference continuing time Tref and detection continuing times Td1 and Td2 are obtained. A logic circuit 91 receives the various kinds of the continuing times sent from the circuit 90, the DC period ratio sent from a control circuit 93 and a signal C from a comparator 94 at the input parts and sends control signals D1, D2, D3 and D4 to an output-level driver 92. The control circuit 93 compares the continuing times Td1 and Td2 with the total continuing time T6 and sends the period ratio DC and a reference current value Iref suitable for the load of the motor from the output. |
