In a drive device, a first connection circuit, a second connection circuit, and a third connection circuit are connected individually between an input end and an output end. A first motor is connected between a connection node between a first input switch and a first output switch of the first connection circuit and a connection node between a third intermediate switch and a third output switch of the third connection circuit. A second motor is connected between a connection node between a second input switch and a second output switch of the second connection circuit and a connection node between a third input switch and the third intermediate switch of the third connection circuit.

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system is electrically connected to the electric motor and includes an H-bridge circuit, an electrically resistive element and an electrically inductive element. The H-bridge circuit includes a high side and a low side. The low side of the H-bridge circuit includes first and second switching devices. The electrically resistive element is electrically connected in series with the first switching device. The electrically inductive element is electrically connected to the electrically resistive element. The control system is configured to control a force applied to the drive system based on a current downstream of the electrically resistive element.

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system is electrically connected to the electric motor and includes an H-bridge circuit, an electrically resistive element and an electrically inductive element. The H-bridge circuit includes a high side and a low side. The low side of the H-bridge circuit includes first and second switching devices. The electrically resistive element is electrically connected in series with the first switching device. The electrically inductive element is electrically connected to the electrically resistive element. The control system is configured to control a force applied to the drive system based on a current downstream of the electrically resistive element.

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 method for controlling an electric motor including a mechanical commutator, includes determining points in time at which commutation takes place by a sensor or without a sensor. The method further includes controlling the electric motor by a supply voltage signal having a sequence of pulses. The method further includes modulating the supply voltage signal by a modulation signal to reduce the magnitude of the supply voltage signal at the commutation points in time.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller utilizes a duty cycle conversion mechanism, such that the motor controller is operated in a constant voltage driving mode or a constant current driving mode. The motor controller is configured to avoid generating switching noise by the constant voltage driving mode or the constant current driving mode. The motor controller is configured to increase a success rate of starting the motor.

A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller utilizes a duty cycle conversion mechanism, such that the motor controller is operated in a constant voltage driving mode or a constant current driving mode. The motor controller is configured to avoid generating switching noise by the constant voltage driving mode or the constant current driving mode. The motor controller is configured to increase a success rate of starting the motor.

An electronic motor control system provides selectable linear and pulse-width modulated (PWM) operation without generating cross-over distortion. The system includes an output stage that has a pair of push-pull drivers each coupled to a terminal of the motor. The electronic motor control system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to an input of the output stage when the pulse-width modulated mode is selected and a linear amplifier stage that provides a linear analog signal to the input of the output stage in linear mode, so that both drivers are operated to supply the current to the motor. In pulse-width modulated mode, a driver is selected for PWM operation, while the other driver is operated to supply a fixed voltage. A feedback control loop motor current and provides outputs to the pulse-width modulator the linear amplifier stage.

An electronic motor control system provides selectable linear and pulse-width modulated (PWM) operation without generating cross-over distortion. The system includes an output stage that has a pair of push-pull drivers each coupled to a terminal of the motor. The electronic motor control system also includes a pulse-width modulated (PWM) driver for providing pulse-width modulated drive signals to an input of the output stage when the pulse-width modulated mode is selected and a linear amplifier stage that provides a linear analog signal to the input of the output stage in linear mode, so that both drivers are operated to supply the current to the motor. In pulse-width modulated mode, a driver is selected for PWM operation, while the other driver is operated to supply a fixed voltage. A feedback control loop motor current and provides outputs to the pulse-width modulator the linear amplifier stage.

A motor system with an input for coupling to a motor control signal that, when presented in a predetermined state, indicates a motor receiving power should be disabled from rotating. The system also includes controller circuitry for providing a disabling signal to motor rotation, independent of processor software control signaling and the power, in response to the control signal.