| 摘要 |
The present invention relates to a household or commercial appliance (1) comprising: a heating chamber (7), a couple of magnetrons (8a)(8b) having relative 5 anodes (TA1)(TA2) and cathodes (TC1)(TC2), a power unit (5, 40, 140) comprising at least a high voltage circuit (9) configured to power-on magnetrons (8a)(8b). The high voltage circuit (9) comprises: a high voltage transformer (13) comprising a primary winding (13a) connected to an alternating voltage source (17) and a secondary high voltage winding (13b) providing an alternating high voltage (V2) having a period (W) 10 comprising two half periods (W1)(W2), a couple of half-wave voltage doubler circuits (15)(16) which are configured to cooperate with the secondary high-voltage winding (13b) in order to provide a doubled high-voltage (DVH), a first and second unidirectional conducting devices (31)(32) which are connected respectively between the half-wave voltage doubler circuits (15)(16) and a reference terminal (30)(33) having 15 a predetermined potential (GND). The first and second unidirectional conducting devices (31)(32) being configured to cause the half-wave voltage doubler circuits (15)(16) to supply, during a period (W) of the alternating high-voltage (V2), the doubled high-voltage (DVH) to the cathode (TC1)(TC2) of the respective magnetron (8a)(8b) alternately. One of the half-wave voltage doubler circuits (15) supplying the 20 doubled high-voltage (DVH) during one half-period (W1) of the alternating high voltage (V2), and the other half-wave voltage doubler circuit (16) supplying the doubled high-voltage (DVH) during the other half-period (W2). (FIG. 3) - 27 - /5 / 8b 8a FIG.3 13 16a 9 ..13c 261/25 ' 2712 0 i V2 VH K 1 TA2 1b29 32 -83b 13 36 15a_ __ _ 21 ----- 35 15---' ' 2 4 3 _34 |
