| 摘要 |
A force sensing device is adapted for sensing thread tension in a long-arm or mid-arm sewing machine. The force sensing device comprises the sewing machine mechanically coupled to a force sensor disk. A user can rotate a tension adjuster knob to increase or decrease thread tension as necessary. The force sensor disk comprises a variable resister that is electrically coupled to a force sensor disk cable; the force sensor disk cable is electrically coupled to a measurement resistor RM, a load resistor RL, a battery and a power switch. As the tension on the force sensor disk increases, the resistance on force sensor disk decreases and voltage across measurement sensor RM increases. A digital readout meter measures the voltage proportional to the tension on the force sensor disk. A voltage relative to tension is displayed on a display screen and can be viewed by the user who can increase or decrease the tension as necessary.
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