Power tool and control method of the same

A power tool, comprising:

• a functional component for realizing a function of the power tool;
• a motor for driving the functional component, the motor having a plurality of windings;
• a power supply module configured to provide a power supply current, the power supply module comprising a first power terminal and a second power terminal;
• a drive circuit electrically connected to the motor, the drive circuit comprising:
• a first drive terminal electrically connected with the first power terminal;
• a second drive terminal electrically connected with the second power terminal;
• a first high-side switch wherein a high-side terminal of the first high-side switch is electrically connected to the first drive terminal;
• a first low-side switch wherein a low-side terminal of the first low-side switch is electrically connected to the second drive terminal;
• a current measuring module configured to detect or estimate phase current;
• and
• a controller configured to:
• output a first control signal to the first high-side switch to place the first high-side switch in an on state or an off state;
• and
• output a second control signal to the first low-side switch to place the first low-side switch in the other of the on state and the off state;
• wherein the low-side terminal of the first high-side switch is connected to the high-side terminal of the first low-side switch and the controller is configured to output the second control signal to turn off the first low-side switches or output the first control signal to turn off the first high-side switches when the phase current is less than or equal to zero.

A power tool, comprising:

• a functional component for realizing a function of the power tool;
• a motor for driving the functional component, the motor having a plurality of windings;
• a power supply module configured to provide a power supply current, the power supply module comprising a first power terminal and a second power terminal;
• a drive circuit electrically connected to the motor, the drive circuit comprising:
• a first drive terminal electrically connected with the first power terminal;
• a second drive terminal electrically connected with the second power terminal;
• a plurality of high-side switches wherein high-side terminals of the plurality of high-side switches are respectively electrically connected to the first drive terminal;
• a plurality of low-side switches wherein low-side terminals of the plurality of low-side switches are respectively electrically connected to the second drive terminal;
• and
• a controller configured to:
• output a first control signal to a one of the plurality of high-side switches to place the one of the plurality of high-side switches in an on state or an off state;
• and
• output a second control signal to a one of the plurality of low-side switches to place the one of the plurality of low-side switches in the other of the on state and the off state,
• wherein the low-side terminal of the one of the plurality of high-side switches is connected to the high-side terminal of the one of the plurality of low-side switches.