AUTOMATIC SEWING THREAD CUTTING CONTROL DEVICE OF SEWING MACHINE

摘要

The apparatus precisely controls sewing speed using a feedback control loop comprising a motor current sensor and speed encoder as a feedback element. The controller includes a motor (1') driving the sewing machine, a pedal (3')/pedal sensor (21) transfering input signals to the motor (1'), a manul switch (22), a control box/input matrix (32), CPU (2') generating a command current for driving the motor by use of the above input signal and a feedback signal, a circuit (26) transfering the motor drive signal to a base driver (29) and n inverter (30), a sensor (27) for detecting the motor's rotor position and a sensor (33) for measuring the amount of the motor current.