Vacuum Tube HF Welder: The GP series H.F. vacuum induction heating equipment adopts vacuum tube as the key parts. The intelligentized control system which has the functions of voltage regulation, resonance, protection, is consisted of singlechip (SCM) as key part, with the merits of easy but reliable circuit and easy maintenance. Equipment composing: step-up transformer, power supply switch gear cabinet, main cabinet, console, output transformer and circulation water cooling system (optional part).