High frequency oscillator, high frequency welding system and method for controlling the frequency using said type of high frequency oscillator

Abstract

A high-frequency oscillator includes an electric resonant circuit, and a high-frequency welding system and a method for controlling the frequency uses a high-frequency oscillator, in particular in a high-frequency welding system. The electric resonant circuit includes at least one electronic component having an inductance and at least one capacitor having a capacitance. At least one additional magnetic coil is associated with the electronic component and can electronically influence the inductance of the electronic component.

What is claimed is: 
     
         1 . A method for controlling a frequency, the method comprising:
 providing a high frequency oscillator having an electric resonant circuit comprising at least one electronic component having an inductance and at least one capacitor, wherein at least one magnetic coil is associated with the electronic component and with which the inductance of the electronic component is electronically influenceable; and   controlling the frequency of the high frequency oscillator wear free by electronically adjusting the inductance.   
     
     
         2 . The method according to  claim 1 , wherein the inductance is adapted by applying a direct current to at least one magnetic coil ( 5 ), which is associated with the electronic component providing the inductance in the electric resonant circuit. 
     
     
         3 . The method according to  claim 1 , wherein an impedance of the electric resonant circuit is adjusted by adapting the inductance. 
     
     
         4 . The method according to  claim 1 , wherein the inductance is gradually or continuously varied in an automatic search run until an optimal frequency is achieved in a load circuit of a high frequency welding system. 
     
     
         5 . The method according to  claim 1 , wherein in high frequency welding systems with high frequency oscillators and/or in high frequency welding systems with solid state amplifiers, the tuning of the magnetic resonant circuit is used as resonance or impedance tuning in the load circuit.