A sewing machine translates a stitchwork frame with which a cloth is fastened along a direction of a plane where the cloth is fastened based on stitchwork data to form a stitchwork pattern. A presser foot located above the cloth has a height changed by an actuator like a stepping motor in accordance with the advancement of a stitchwork formation. Hence, a predetermined clearance between the cloth and the presser foot is maintained.

A sewing machine translates a stitchwork frame with which a cloth is fastened along a direction of a plane where the cloth is fastened based on stitchwork data to form a stitchwork pattern. A presser foot located above the cloth has a height changed by an actuator like a stepping motor in accordance with the advancement of a stitchwork formation. Hence, a predetermined clearance between the cloth and the presser foot is maintained.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A longarm quilting machine having a frame with an upper arm and a lower arm. A needle bar drive mechanism configured to be combined with a needle is combined with a portion of the upper arm and a bobbin hook assembly configured to be combined with a bobbin is combined with a portion of the lower arm. A needle motor is operatively combined with the needle bar drive mechanism and configured to provide torque to the needle bar drive mechanism to cause the needle to move up and down. A bobbin motor is operatively combined with the bobbin hook assembly and configured to provide torque to the bobbin hook assembly causing the bobbin to rotate beneath the needle. A controller is in communication with the needle motor and the bobbin motor to determine whether the components are synchronized and run a synchronization mode upon the occurrence of certain predetermined events.

A longarm quilting machine having a frame with an upper arm and a lower arm. A needle bar drive mechanism configured to be combined with a needle is combined with a portion of the upper arm and a bobbin hook assembly configured to be combined with a bobbin is combined with a portion of the lower arm. A needle motor is operatively combined with the needle bar drive mechanism and configured to provide torque to the needle bar drive mechanism to cause the needle to move up and down. A bobbin motor is operatively combined with the bobbin hook assembly and configured to provide torque to the bobbin hook assembly causing the bobbin to rotate beneath the needle. A controller is in communication with the needle motor and the bobbin motor to determine whether the components are synchronized and run a synchronization mode upon the occurrence of certain predetermined events.

A longarm quilting machine having a frame with an upper arm and a lower arm. A needle bar drive mechanism configured to be combined with a needle is combined with a portion of the upper arm and a bobbin hook assembly configured to be combined with a bobbin is combined with a portion of the lower arm. A needle motor is operatively combined with the needle bar drive mechanism and configured to provide torque to the needle bar drive mechanism to cause the needle to move up and down. A bobbin motor is operatively combined with the bobbin hook assembly and configured to provide torque to the bobbin hook assembly causing the bobbin to rotate beneath the needle. A controller is in communication with the needle motor and the bobbin motor to determine whether the components are synchronized and run a synchronization mode upon the occurrence of certain predetermined events.

A longarm quilting machine having a frame with an upper arm and a lower arm. A needle bar drive mechanism configured to be combined with a needle is combined with a portion of the upper arm and a bobbin hook assembly configured to be combined with a bobbin is combined with a portion of the lower arm. A needle motor is operatively combined with the needle bar drive mechanism and configured to provide torque to the needle bar drive mechanism to cause the needle to move up and down. A bobbin motor is operatively combined with the bobbin hook assembly and configured to provide torque to the bobbin hook assembly causing the bobbin to rotate beneath the needle. A controller is in communication with the needle motor and the bobbin motor to determine whether the components are synchronized and run a synchronization mode upon the occurrence of certain predetermined events.