A tool for working a substrate, the tool having a stator and a working piston, which is intended to move relative to the stator along a working axis and toward the substrate or to hit a fastening element in order to drive the fastening element into the substrate, also having a drive, which is intended to drive the working piston along the working axis onto the substrate, the drive having a capacitor and a piston coil arranged on the working piston, the piston coil being electrically connectable to the capacitor in order during rapid discharge of the capacitor to have a current flowing through it and to generate a magnetic field which accelerates the working piston relative to the stator, the drive having a diode which is arranged on the working piston and is electrically connected to the piston coil.

A tool for working a substrate has a stator and a working piston, which is intended to move relative to the stator along a working axis, also having a drive, which is intended to drive the working piston from a starting position along the working axis to the substrate, the drive comprising a piston coil arranged on the working piston and a first stator coil arranged on the stator, and the first piston coil being intended to enter the first stator coil during a movement of the working piston relative to the stator along the working axis.

Controllers for controlling hybrid motor drive circuits configured to drive a motor are provided herein. A controller is configured to drive the motor using an inverter when a motor commanded frequency is not within a predetermined range of line input power frequencies, and couple line input power to an output of the inverter using a first switch device when the motor commanded frequency is within the predetermined range of line input power frequencies.

Controllers for controlling hybrid motor drive circuits configured to drive a motor are provided herein. A controller is configured to drive the motor using an inverter when a motor commanded frequency is not within a predetermined range of line input power frequencies, and couple line input power to an output of the inverter using a first switch device when the motor commanded frequency is within the predetermined range of line input power frequencies.

A long-distance speed control system for a brushless DC motor of a fan is provided. The long-distance speed control system includes a switch connected with a mains power supply, a switch circuit, a voltage detection module, a power cord, a processing unit, and a drive unit, which can control the multi-stage rotational speed of the motor. In the field of brushless DC motors for fans, there is no need to use analog-to-digital conversion chips between the mains power supply and the processor, having the advantages of low cost, environmental protection, and reduction of waste of earth resources. Besides, the switch, the switch circuit and the power cord can withstand the mains power supply, having the advantages of less signal attenuation and long-distance transmission.

An electric motor system is described. The electric motor system includes a drive circuit including an inverter configured to supply variable frequency current and a contactor configured to supply line frequency current. The electric motor system also includes an electric motor coupled to the drive circuit wherein the electric motor is communicatively coupled to a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor, thereby operating the electric motor at a motor speed, and determine, based upon at least one input parameter, a maximum potential motor speed the inverter can achieve. The controller is also configured to receive a command to operate the electric motor at line frequency current and control the drive circuit to transition from supplying variable frequency current to supplying line frequency current before the maximum potential motor speed the inverter can achieve is reached.

An electric motor system is described. The electric motor system includes a drive circuit configured to supply variable frequency current and a contactor configured to supply line frequency current, wherein the drive circuit includes a three-phase inverter and an H-bridge including two phases of the inverter. The electric motor system also includes an electric motor and a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor over a first duration and determine to control the drive circuit to transition from supplying variable frequency current to supplying line frequency current. The controller is also configured to determine a polarity of a sensed alternating current (AC) voltage, disable at least two switches of the H-bridge, and control the contactor to close, thereby preventing the contactor and the inverter from energizing the electric motor at the same time once the contactor is closed.

A long-distance speed control system for a brushless DC motor of a fan is provided. The long-distance speed control system includes a switch connected with a mains power supply, a switch circuit, a voltage detection module, a power cord, a processing unit, and a drive unit, which can control the multi-stage rotational speed of the motor. In the field of brushless DC motors for fans, there is no need to use analog-to-digital conversion chips between the mains power supply and the processor, having the advantages of low cost, environmental protection, and reduction of waste of earth resources. Besides, the switch, the switch circuit and the power cord can withstand the mains power supply, having the advantages of less signal attenuation and long-distance transmission.

A control system for a permanent split capacitor (PSC) motor is provided herein. The control system includes a motor drive circuit configured to condition AC input voltage from an AC voltage source to an output voltage for operating the PSC motor at a variable speed. The control system also includes a switch device configured to couple the AC input voltage from the AC voltage source directly to the PSC motor for operating the PSC motor at a fixed speed.

A system in which the operation of an electric motor is controlled by electronically controlled switches. The system includes the motor having a run winding and a start winding, a heating component, and a motor control subsystem. A control unit closes a first switch to energize the run winding, closes a second switch to energize the start winding, determines based on an amplitude and a lag time of a current flowing through the motor whether the motor has started and is running normally, and if so, opens the second switch to de-energize the start winding and closes a third switch to activate the heating component. The control unit determines whether the motor has started and is running normally by comparing the real time amplitude and lag time of the current to a plurality of stored amplitudes and lag times associated with different operating conditions.