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 system includes a trickle charge control circuit coupled to a charge pump and a motor driver circuit. The trickle charge control circuit is configured to sense a voltage at a bootstrap capacitor voltage node (VBST) of the motor driver circuit; as a result of the voltage at VBST being greater than a voltage at an input voltage node (VIN), couple a charge pump voltage node (VCP) to VBST of the motor driver circuit, where a voltage at VCP is greater than the voltage at VIN; and as a result of the voltage at VBST being less than the voltage at VIN, decouple VCP from the charge pump from VBST of the motor driver circuit.

A system includes a trickle charge control circuit coupled to a charge pump and a motor driver circuit. The trickle charge control circuit is configured to sense a voltage at a bootstrap capacitor voltage node (VBST) of the motor driver circuit; as a result of the voltage at VBST being greater than a voltage at an input voltage node (VIN), couple a charge pump voltage node (VCP) to VBST of the motor driver circuit, where a voltage at VCP is greater than the voltage at VIN; and as a result of the voltage at VBST being less than the voltage at VIN, decouple VCP from the charge pump from VBST of the motor driver circuit.

An electric tool control circuit includes a central control module, a motor drive module, a motor, and a working parameter detection module. The working parameter detection module can detect and communicate a parameter to the central control module related to a load on the motor detected during running of the motor. The motor drive module is separately electrically connected to the motor by using first and second switch modules, and the motor drive module controls the first and second modules to be discontinuously on and off to thereby reduce variation of a speed of the motor caused by a variation of the load on the motor. The status of the first and second switch modules being on and off are always contrary. A related method is disclosed.

An electric tool control circuit includes a central control module, a motor drive module, a motor, and a working parameter detection module. The working parameter detection module can detect and communicate a parameter to the central control module related to a load on the motor detected during running of the motor. The motor drive module is separately electrically connected to the motor by using first and second switch modules, and the motor drive module controls the first and second modules to be discontinuously on and off to thereby reduce variation of a speed of the motor caused by a variation of the load on the motor. The status of the first and second switch modules being on and off are always contrary. A related method is disclosed.

A motor drive system includes a rectifier circuit, a controller, a modulator circuit and a direct current (DC) motor. The rectifier circuit is configured to convert an alternating current (AC) voltage to a DC voltage. The controller is configured to output a control signal. The modulator circuit includes a pulse generation module, a feedback determination module, a pulse modulation module and a driving module, and is configured to generate a modulated DC driving signal based on the DC voltage and the control signal generated by the rectifier circuit and the controller. The DC motor is configured to operate in accordance with the modulated DC driving signal generated by the modulator circuit.

A voltage regulation and speed regulation control circuit (100, 130, 200, 250) of an air pump (102) is provided. The voltage regulation and speed regulation control circuit (100, 130, 200, 250) may comprise a chopper power supply circuit (104, 202), a full bridge rectifier circuit (106, 204) and a switch (108, 212). The switch (108, 212) may be used to switch the chopper power supply circuit (104, 202) or the full bridge rectifier circuit (106, 204) to be connected to the positive and negative input terminals (103, 105) of the air pump (102). The output voltage of the chopper power supply circuit (104, 202) and the output voltage of the full bridge rectifier circuit may be different (106, 204).

The present disclosure is an apparatus for testing an idle position of a servo, including: driving mechanism, a transmission unit transmitting torque of a driving servo to a testing servo, and a control circuit electrically connecting to the driving servo and the testing servo to acquire idle position information. The apparatus drives the output shaft of the testing servo to rotate by an external driving mechanism, and measures an amount of rotation of the output shaft by an internal sensor of the testing servo. Therefore, an external sensor may not be provided, and a problem of precision installation of the external sensor can be avoided. Further, a problem caused by poorly install the external sensor and the output shaft can also be avoided, and accuracy of a testing result can be increased.

The present disclosure is an apparatus for testing an idle position of a servo, including: driving mechanism, a transmission unit transmitting torque of a driving servo to a testing servo, and a control circuit electrically connecting to the driving servo and the testing servo to acquire idle position information. The apparatus drives the output shaft of the testing servo to rotate by an external driving mechanism, and measures an amount of rotation of the output shaft by an internal sensor of the testing servo. Therefore, an external sensor may not be provided, and a problem of precision installation of the external sensor can be avoided. Further, a problem caused by poorly install the external sensor and the output shaft can also be avoided, and accuracy of a testing result can be increased.

An electric tool control circuit includes a central control module, a motor drive module, a motor, and a working parameter detection module. The working parameter detection module is separately electrically connected to the motor and the central control module, and the working parameter detection module can return a parameter that is detected when the motor works to the central control module. The motor drive module is separately electrically connected to the motor by using first and second switch modules, and the motor drive module controls the first and second modules to be discontinuously on and off. The features of first switch module and the second switch module being on and off are always contrary, that is, when a first switch is on, a second switch is off, and when the first switch is off, the second switch is on.