Power tools are hand-holding operations to low-power motor or solenoid as a driving force transmission mechanism is driven by job working head of the tool. It's a great variety of widely used.
1895, Germany created the world's first direct current drilling. In 1927, there have been power supply frequency of 150 ~ 200Hz IF power tools, the 1960s, with the development of battery manufacturing technology, the emergence of nickel-cadmium batteries for power no power cord of the battery-operated power tool. also appeared electronic speed power tools. by the late 70s, lower prices due to the battery, the charging time is shortened, the power tool in Europe, Japan and widely used electric utilities were used cast iron for the housing, after the switch to aluminum for housing.
Up to now the electric tool for development more mature, different brands of power tools are constantly rising, giving you more and more choices.