A cordless power tool system including (a) a multi-voltage battery pack for use with tools of different operating voltages including a housing, a first string of battery cells arranged in electrical series and disposed inside the housing, a second string of battery cells arranged in electrical series and disposed inside the housing, and a power tool interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage, and (b) a battery pack charger configured to charge the multi-voltage battery pack.

A power tool system including a multi-voltage battery pack for use with a first power tool, wherein the first power tool comprises a first battery pack interface and is configured to operate at a first operating voltage and a second power tool configured for use with the multi-voltage battery pack such that the system includes both the multi-voltage battery pack and the second power tool, wherein the second power tool comprises a second battery pack interface and is configured to operate at a second operating voltage, wherein the second operating voltage is higher than the first operating voltage.

A power tool system including a multi-voltage battery pack for use with a first power tool, wherein the first power tool comprises a first battery pack interface and is configured to operate at a first operating voltage and a second power tool configured for use with the multi-voltage battery pack such that the system includes both the multi-voltage battery pack and the second power tool, wherein the second power tool comprises a second battery pack interface and is configured to operate at a second operating voltage, wherein the second operating voltage is higher than the first operating voltage.

A system comprising a multi-voltage battery pack for use with tools of different operating voltages, including a housing and a power tool interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage and is of a design that was on sale prior to May 18, 2014 and, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage and is of a design that was not on sale prior to May 18, 2014.

A system comprising a multi-voltage battery pack for use with tools of different operating voltages, including a housing and a power tool interface shaped and configured to interchangeably (1) mechanically and electrically couple with a first battery pack interface of a first power tool that is configured to operate at a first operating voltage and is of a design that was on sale prior to May 18, 2014 and, and (2) mechanically and electrically couple with a second battery pack interface of a second power tool that is configured to operate at a second operating voltage and is of a design that was not on sale prior to May 18, 2014.

A power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

A power tool system includes a first power tool having a first power tool rated voltage, a second power tool having a second power tool rated voltage that is different from the first power tool rated voltage, and a first battery pack coupleable to the first power tool and to the second power tool. The first battery pack is switchable between a first configuration having a first battery pack rated voltage that corresponds to the first power tool rated voltage such that the first battery pack enables operation of the first power tool, and a second configuration having a convertible battery pack rated voltage that corresponds to the second power tool rated voltage such that the battery pack enables operation of the second power tool.

A power tool is configured to receive power from a power supply. The power tool may include a rectifier that may output a rectified signal to a DC power bus. A switching arrangement may operate to deliver electric power from the DC power bus to an electric motor. A switch path may be electrically coupled in parallel with the rectifier on the DC power bus. The switch path includes an auxiliary capacitor in series with a switch and a state of the switch controls a discharging path for the auxiliary capacitor. A switch control circuit may be configured to detect voltage associated with at least one of the AC power supply or the DC power bus and to control state of the switch in accordance with magnitude of the detected voltage.

In a current sensor abnormality diagnosis device, an abnormality judgment section determines that the phase current sensors are operating normally when a sum of three phase currents is not more than a threshold value, and a bus current sensor is operating normally based on a comparison result between three phase currents and a bus current. The abnormality judgment section detects which the phase current sensor has failed based on the three phase currents and the bus current when the sum of the three phase currents is more than the threshold value. Because of using the comparison results of the three phase currents with the bus current in addition to the sum of the three phase currents, it is possible for the abnormality judgment section to detect the occurrence of abnormality of each of these current sensors even if the detected current has an undefined value.

A multi-axis servo control system includes a plurality of motors and a plurality of drive control apparatuses. The drive control apparatuses are connected to each other through an external field bus. Each drive control apparatus includes a control unit and a plurality of drive units. The drive units are connected to the control unit in series by a plurality of local buses to form a series-connected communication loop of sequentially transmitting data. Each drive unit controls at least one of the motors. The control unit receives multi-axis position commands through the external field bus, and the drive units correspondingly receive multi-axis commands through the local buses so as to control the motors in a decentralization manner.