초록 ▼

A dual-mode system for operating electrically powered devices, such as hand-held power tools and appliances, includes a cordless battery pack that supplies the power and current demands of the device in a cordless mode or a corded voltage converter that supplies the necessary power and current deman

A dual-mode system for operating electrically powered devices, such as hand-held power tools and appliances, includes a cordless battery pack that supplies the power and current demands of the device in a cordless mode or a corded voltage converter that supplies the necessary power and current demands in a physical envelope commensurate in size and interchangeable with that of the battery pack. The corded voltage converter is provided with a high efficiency power supply that allows the converter to generate the power and current required by the driven device and accommodate widely varying loads consequent to normal operation of the device and do so in a physical envelope that is commensurate in size with and interchangeable with the cordless battery pack. The corded voltage converter includes a power conditioner that conditions input source current, such as 120 or 240 volts AC or DC, to provide a relatively high DC voltage that is chopped at a comparatively high frequency, e.g., 25 KHz, by switching devices. The high-frequency, high voltage current is presented to a step-down transformer with the stepped-down output rectified to provide a low-voltage DC current to a drive motor of the device.

대표청구항 ▼

A corded/cordless system for power-operated apparatus, comprising: an electrically power-operated device operable in a preselected voltage range; means defining an interface for electrically and mechanically mating said device with one of a plurality of electric-power supply devices, said interface

A corded/cordless system for power-operated apparatus, comprising: an electrically power-operated device operable in a preselected voltage range; means defining an interface for electrically and mechanically mating said device with one of a plurality of electric-power supply devices, said interface means defining a pre-determined physical envelop configuration for mechanically mating with the power supply devices; first supply means defining a cordless electric-power supply device for electrically and mechanically mating with said power-operated device through said interface, said cordless electric-power supply device containing cells capable of providing 50 or more watts of power in the selected voltage range to said power-operated device; second supply means defining a corded electric-power supply device for electrically and mechanically mating with said power-operated device, said corded electric-power supply device having a power cord for connection to a source of electrical energy therethrough and containing an electrical power converter for converting the source electrical energy to 50 or more watts of power in the selected voltage range; and wherein said second supply means comprises voltage converter means for converting the source electrical energy into an alternating voltage of a selected frequency and converting the alternating voltage to a lower rectified voltage in the selected voltage range.