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 hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.

Included herein is a circuit comprising resistors, capacitors, relays, diode bridges, TRIACs, and DIACs mounted to a substrate. The circuit may be electrically connected to a user device containing a wide range of types and specifications of AC induction motors. The circuit may be installed plug-and-play onto a user device, without the need for tools, custom installation or deconstruction of a user device. Upon user direction or automatically, the circuit may inject DC current into the user tool which generates a stationary magnetic field inside the AC induction motor causing deceleration/arrestment of the AC induction motor's rotor. The circuit may prevent unintended acceleration of the rotor upon powering on the user device. Also included is a method for prevention of unintended acceleration of the rotor upon powering on the user device. Also included is a method for decelerating/arresting an AC induction motor.

A drive circuit for a permanent split capacitor (PSC) motor includes an inverter, a solid state switch, and a contactor coupled in parallel with the solid state switch. The inverter is configured to supply variable frequency current to the PSC motor over a first duration. The solid state switch is configured to supply line frequency current to the PSC motor at the expiration of the first duration. The contactor is configured to supply the line frequency current to the PSC motor over a second duration beginning when the contactor closes after expiration of the first duration.

A compressor for commercial refrigerators comprises an electric motor having a start winding (120) and a run winding (130), in which the input terminals of the start winding (120) and the run winding (130) are connected together and to the line voltage (L), and an electronic start device to supply the start winding (120) during a starting period. The electronic start device comprises a run condenser (40) having a first terminal connected to the output terminal from the start winding (120) and a second terminal connected to the output terminal from the run winding (130), and a start capacitor (45) having a first terminal connected to the output terminal of the start winding (120). In the electronic start device there is also provided a solid state switch (110) which supplies the start winding (120) and is connected between the second terminal of the start capacitor (45) and the neutral terminal of the supply (N), and a control circuit (100) comprising a delay circuit (210, 220) which controls switching of the solid state switch (110) closing it to start the motor and opening it at the end of the starting period once the motor has started.

A compressor for commercial refrigerators comprises an electric motor having a start winding (120) and a run winding (130), in which the input terminals of the start winding (120) and the run winding (130) are connected together and to the line voltage (L), and an electronic start device to supply the start winding (120) during a starting period. The electronic start device comprises a run condenser (40) having a first terminal connected to the output terminal from the start winding (120) and a second terminal connected to the output terminal from the run winding (130), and a start capacitor (45) having a first terminal connected to the output terminal of the start winding (120). In the electronic start device there is also provided a solid state switch (110) which supplies the start winding (120) and is connected between the second terminal of the start capacitor (45) and the neutral terminal of the supply (N), and a control circuit (100) comprising a delay circuit (210, 220) which controls switching of the solid state switch (110) closing it to start the motor and opening it at the end of the starting period once the motor has started.

A hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are 4 metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.

A hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are 4 metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.

A hard start capacitor replacement unit includes a capacitor container having a cover, a plurality of capacitors received within the container, each of said capacitors having a capacitance value, a common terminal mounted on the cover and electrically connected to a common terminal of each of said plurality of capacitors, a plurality of cover terminals mounted on the cover spaced apart from the common terminal and from each other, each cover terminal respectively electrically connected to one of the plurality of capacitors, a relay having contacts and being capable of opening and closing said contacts in response to a monitored condition of the motor, the relay having relay terminals, a fuse electrically connected to one of the relay terminals by a first wire wherein the fuse electrically disconnects the hard start capacitor replacement unit and the motor upon a failure, and a second wire electrically connecting one of the relay terminals and the motor, a third wire electrically connecting the common terminal and one of the relay terminals, a fourth wire electrically connecting one or more cover terminals to one of the relay terminals, wherein the contacts of the relay close to electrically connect one or more capacitors of the plurality of capacitors to the motor, and the contacts of the relay open to electrically disconnect the one or more capacitors of the plurality of capacitors from the motor.

A hard start capacitor replacement unit has a plurality of capacitors in a container sized to fit in existing hard start capacitor space. The capacitors are 4 metallized film capacitors wound in a single cylindrical capacitive element. The container has a common terminal and capacitors value terminals for the plurality of capacitors, which may be connected singly or in combination to provide a selected capacitance. An electronic or other relay connects the selected capacitance in parallel with a motor run capacitor. The hard start capacitor replacement unit is thereby adapted to replace a wide variety of hard start capacitors.