| 摘要 |
A high-frequency converter of push-pull form comprises a centre tapped D.C. input supply (16, 17, 18,) two solid state switching devices (20,21) connected in series across the D.C. input terminals, a load circuit including a supersonic frequency transformer (30) and an output rectifier (35), and an oscillatory circuit including at least one capacitor (40) and a parallel inductor (34) connected in parallel with the primary winding (37) of the transformer between the centre tapping (19) of the supply and the junction (25) of the switching devices. The switching devices are synchronised to the oscillation of the oscillatory circuit to allow the circuit to oscillate freely for part of a cycle to transfer energy from the inductor (34) to the capacitor (40) to charge the latter to a certain condition in which the voltage across the parallel inductor is substantial and that across the switching device is negligible and only then connect the parallel inductor across the D.C. input terminals whereupon the parallel inductor receives and stores energy from the said supply. Means such as a saturable reactor (33) are connected in series in the load circuit to restrict load current to a low value during a part of the cycle in which the capacitor receives energy from the parallel inductor and until the capacitor is charged to the said condition and the switching means has connected the load circuit across the supply. |
