Abstract: A motor driving apparatus includes: a switch having a first terminal that receives an external voltage, and a second terminal; a driving circuit coupled to the first terminal of the switch, and powered by the external voltage; a control circuit coupled to the second terminal of the switch; and a power circuit coupled across the switch, and outputting an internal voltage associated with the external voltage to power the control circuit to control the driving circuit to drive a motor of a power tool to rotate in a first direction when the switch operates in the ON state and to rotate in a second direction for a predetermined time period counting from each instance the switch transitions to the OFF state.

Abstract: A power beating device using includes a driving unit and an actuator. The driving unit has a spring for storing and releasing energy so as to drive an impact unit. The driving unit has at least one driving surface. The actuator serves for actuating the driving surface so that the impact unit is lifted with the driving unit. Deformation of the spring will store energy. When the impact unit is lifted to a predetermined height, it will rest and then the spring will release energy to drive the impact unit to have the effect of beating.

Abstract: Device for pumping viscous materials, particularly sealant and grease, without dripping and method of the same are characterized by storing a predetermined portion of the driving energy in form of an angular and/or linear displacement of a torsional spring. This very portion of the stored energy will be released at the end of the operation when the operator let go the trigger, whereby the released energy will drive the final transmission and the end part of the final transmission to move backwards for a predetermined amount of displacement. This backwards movement of the end part of the final transmission causes the volume of viscous material to expand suddenly; this expansion of the volume of viscous material compensates the compression of the viscous material from the dispensing process, which will also draw back the viscous material on its way outward for to work and for to drip.