Patent ID: 11897339
Assignee: MAKITA CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC B  H | IPC B  H

Claim 2:
3. A cart comprising:
a driving wheel;
a motor configured to rotate the driving wheel;
a motor drive circuit configured to drive the motor;
a motor brake circuit configured to electrically brake the motor;
a rotation speed sensor configured to detect a rotation speed of the motor;
a control device configured to control the motor via the motor drive circuit and the motor brake circuit based on a target rotation speed of the motor and the rotation speed detected by the rotation speed sensor;
a second driving wheel;
a second motor configured to rotate the second driving wheel;
a second motor drive circuit configured to drive the second motor;
a second motor brake circuit configured to electrically brake the second motor; and
a second rotation speed sensor configured to detect a rotation speed of the second motor, wherein
the control device is also configured to control the second motor via the second motor drive circuit and the second motor brake circuit based on a target rotation speed of the second motor and the rotation speed detected by the second rotation speed sensor,
the motor brake circuit includes a semiconductor element configured to operate in a first mode and a second mode in response to a control input signal,
the second motor brake circuit includes a second semiconductor element configured to operate in a third mode and a fourth mode in response to a second control input signal,
brake current for electrically braking the motor flows in the semiconductor element,
second brake current for electrically braking the second motor flows in the second semiconductor element,
when the semiconductor element operates in the first mode, the magnitude of the brake current changes substantially linearly when the control input signal changes,
when the second semiconductor element operates in the third mode, the magnitude of the second brake current changes substantially linearly when the second control input signal changes,
when the semiconductor element operates in the second mode, the magnitude of the brake current changes less than the magnitude of the brake current changes in the first mode when the control input signal changes,
when the second semiconductor element operates in the fourth mode, the magnitude of the second brake current changes less than the magnitude of the second brake current changes in the third mode when the second control input signal changes,
the motor brake circuit is configured to operate the semiconductor element in the first mode when braking the motor, and
the second motor brake circuit is configured to operate the second semiconductor element in the third mode when braking the second motor.