Abstract: Various embodiments of the present invention are directed to electrical plug apparatus for selectively connecting a device such as a battery charger, for example, to sources of AC and DC electrical power and comprise a housing, a first connector attached to the housing for connecting to a DC source of electrical power, a second connector attached to the housing for connecting to an AC source of electrical power wherein the first and second connectors are configured to enable only one of the connectors to be used at the same time.

Abstract: A selectively detachable measuring and recording module for use with a hand tool including a module housing configured to be assembled to the hand tool, a measuring device coupled to the module housing, and a sound recording and playback device disposed within the module housing.

Abstract: A DC—DC voltage converter that is capable of increasing as well as decreasing the voltage of a battery pack for application to a power tool or other load. The converter thereby enables different voltage batteries to be used with power tools that have motors that operate at different voltages. The voltage conversion is accomplished by using a relatively high speed switching circuit wherein the duty cycle of the switching circuitry varies the output voltage. An alternative embodiment utilizes feedback control circuitry to automatically adjust the duty cycle so that the speed of the motor, which is a function of the voltage applied to it, would be held generally constant.

Abstract: A DC-DC voltage converter that is capable of increasing as well as decreasing the voltage of a battery pack for application to a power tool or other load. The converter thereby enables different voltage batteries to be used with power tools that have motors that operate at different voltages. The voltage conversion is accomplished by using a relatively high speed switching circuit wherein the duty cycle of the switching circuitry varies the output voltage. An alternative embodiment utilizes feedback control circuitry to automatically adjust the duty cycle so that the speed of the motor, which is a function of the voltage applied to it, would be held generally constant.

Abstract: A power supply for a power tool which is adapted to be powered by a battery source and an AC voltage source includes a battery module constructed and adapted to be removably coupled to the power tool. The battery module includes a battery pack for supplying power to the power tool. A power converter module supplies current for charging the battery pack and for operating the power tool. A power plug extends from the power converter module and is adapted to be connected to the battery module. The power plug has a first output for supplying the tool operating current to the power tool and a second output for supplying the battery charging current to the battery pack when the plug is connected to the battery module. A switching device is provided in the battery module for electrically disconnecting the battery pack from the power tool responsive to the plug being connected to the battery module.

Abstract: A power supply for a power tool which is adapted to be powered by a battery source and an AC voltage source includes a battery module constructed and adapted to be removably coupled to the power tool. The battery module includes a battery pack for supplying power to the power tool. A power converter module supplies current for charging the battery pack and for operating the power tool. A power plug extends from the power converter module and is adapted to be connected to the battery module. The power plug has a first output for supplying the tool operating current to the power tool and a second output for supplying the battery charging current to the battery pack when the plug is connected to the battery module. A switching device is provided in the battery module for electrically disconnecting the battery pack from the power tool responsive to the plug being connected to the battery module.

Abstract: An AC to DC power supply is disclosed which converts an AC input voltage to a DC output voltage and supplies the DC output voltage to power devices. The power supply includes a transformer for reducing a voltage level of the AC input voltage and an energy storage device in the form of a Bolder battery that has low internal resistance and is capable of generating high power generally instantaneously. The energy storage device enables the power supply to meet high electrical loads that exceed the output of the transformer.

Abstract: A power supply converts an AC input voltage to a DC output voltage and supplies the DC output voltage to power devices. The power supply includes a housing, a transformer provided in the housing for reducing a voltage level of the AC input voltage and a thermal protection device thermally connected between the AC input voltage and the transformer for electrically disconnecting the AC input voltage from the transformer when activated responsive to the transformer exceeding a predetermined temperature. A rectifier is electrically connected to the transformer for rectifying the AC input voltage reduced by the transformer into the DC output voltage which is supplied to the power devices.