| 摘要 |
PROBLEM TO BE SOLVED: To provide a sewing machine which can detect a load applied on a motor for the sewing machine as quick as possible and can quickly exhibit such a power that makes a needle surely penetrate a fabric. SOLUTION: In the sewing machine provided with a needle moving up and down by rotating a main shaft and the motor 1 for the sewing machine for rotating the main shaft, a CPU 12 detects change in phase electric current of the motor 1 for the sewing machine and when elevation of the phase electric current is detected, width of a PWM pulse signal outputted in accordance with degree of the elevation is increased.
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