HF workpiece machining appts. - has cavity resonator into which workpiece is placed under pressure application (NL220676)

摘要

The high frequency machining apparatus comprises further a triode tube whose anode is connected to the cavity resonator interior, and a feedback coil inside the resonator providing feed back to the triode tube grid. It comprises means for a supply voltage application to the valve at a low or at a higher level. A variable capacitor between the feedback coil and the triode tube grid control the increase of the grid current and the build-up of a high frequency field in the cavity resonator. When the grid current reaches a specified value a relay switches over from a lower to the higher voltage level. Preferably the voltage derived from the grid is compared with a reference, and a motor for changing the capacitor values is started, on non-agreement.