Supply device with a controlled power delivering inverter

Device for feeding an inverter to a resonant circuit, used in furnaces induction heating cookers. The device includes a first unit (10) to provide an instantaneous measurement of the current (i) flowing in the resonant circuit (2, 5) and a second unit (20) to evaluate the maximum current (Imax) from instantaneous current. There is a third unit (30) to evaluate the instantaneous current from the switching current for this switch (TB) or freewheeling diode that is associated to become conductor (Iconmut). The first control unit (55) switch (TA, TB) receives the maximum current, the switching current (Iconmut) and a data line guide User (CU), modify the data as a function of the maximum current and the switching current, and supplies a periodic signal as a function of this modified guide (C) line.