US 11,942,834 B2
Motor drive system and motor drive method
Chin-Shu Yang, Taichung (TW); and Chih-Huang Wu, Taichung (TW)
Assigned to ZENG HSING INDUSTRIAL CO., LTD., Taichung (TW)
Filed by ZENG HSING INDUSTRIAL CO., LTD., Taichung (TW)
Filed on Mar. 7, 2022, as Appl. No. 17/688,112.
Claims priority of application No. 110135612 (TW), filed on Sep. 24, 2021.
Prior Publication US 2023/0099313 A1, Mar. 30, 2023
Int. Cl. H02K 11/33 (2016.01); D05B 69/12 (2006.01); D05B 69/30 (2006.01); H02K 7/14 (2006.01); H02K 11/04 (2016.01)
CPC H02K 11/33 (2016.01) [D05B 69/12 (2013.01); D05B 69/30 (2013.01); H02K 7/14 (2013.01); H02K 11/04 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A motor drive system adapted to receiving an alternating current (AC) voltage and driving a sewing machine to sew with a needle of the sewing machine, the motor drive system comprising:
a rectifier circuit configured to receive the AC voltage, convert the AC voltage thus received to a direct current (DC) voltage that is higher than one hundred volts, and output the DC voltage;
a controller configured to output a control signal;
a modulator circuit electrically connected to said rectifier circuit and said controller to receive the DC voltage and the control signal, and configured to generate a modulated DC driving signal based on the DC voltage and the control signal, and output the modulated DC driving signal; and
a DC motor electrically connected to said modulator circuit to receive the modulated DC driving signal, and configured to operate at a rotational speed corresponding to the modulated DC driving signal in order to drive the needle of the sewing machine to move correspondingly,
wherein said modulator circuit includes a pulse generation module, a feedback determination module, a pulse modulation module and a driving module,
wherein said pulse generation module is electrically connected to said controller to receive the control signal from said controller, and configured to generate an original pulse signal based on the control signal, and output the original pulse signal;
wherein said feedback determination module is configured to receive a feedback signal, generate a feedback determination signal based on the feedback signal, which is related to an average voltage of the feedback signal, and output the feedback determination signal;
wherein said pulse modulation module is electrically connected to said pulse generation module to receive the original pulse signal, electrically connected to said feedback determination module to receive the feedback determination signal, and configured to generate a modulated pulse signal having a modulated duty cycle based on the original pulse signal and the feedback determination signal, and to output the modulated pulse signal, the modulated duty cycle having a positive correlation with the average voltage of the feedback signal;
wherein said driving module includes a positive output terminal and a negative output terminal electrically connected to said DC motor, is electrically connected to said feedback determination module, is further electrically connected to said rectifier circuit and said pulse modulation module to receive the DC voltage and the modulated pulse signal, and is configured to:
modulate the DC voltage based on the modulated pulse signal to generate the modulated DC driving signal,
generate the feedback signal the average voltage of which corresponds to an average voltage of the modulated DC driving signal, and
output the modulated DC driving signal via said positive output terminal and said negative output terminal to said DC motor, and the feedback signal to said feedback determination module.