In 1895, the German overtone made the world's first DC drill. The housing is made of cast iron and can drill a 4mm hole in the steel plate. Then a three-phase power frequency (50Hz) electric drill appeared, but the motor speed failed to exceed 3000r/min. In 1914, electric tools driven by single-phase series excitation motors appeared, and the motor speed reached more than 10000r/min. In 1927, an intermediate frequency power tool with a power supply frequency of 150-200Hz appeared. It not only has the advantages of high speed of a single-phase series motor, but also has the advantages of a simple and reliable structure of a three-phase power frequency motor, but it needs to be powered by an intermediate frequency current. , use is restricted.
TSTOP and SOM brands tools with market users in more than 120 countries and regions around the world, the annual export volume is 200 million US dollars.
Cod QR