| 摘要 |
A deflection circuit (39) is coupled to a horizontal deflection winding (Ly) for generating scanning current in the winding. A retrace pulse voltage is developed across the deflection winding (Ly) during the retrace interval. A flyback transformer (T1) is coupled to the deflection circuit (39) and has retrace pulse voltages developed across windings thereof. A source (19) of supply energy is coupled to a first winding (W1) of the flyback transformer (T1) and a load circuit, such as a high power audio circuit (36), is coupled to a second winding (W4) of the transformer and draws load current therefrom. A switched mode power supply (S1,S2) is coupled to the source (19) of supply energy and to the flyback transformer (T1) for controlling the transfer of energy between the source (19) and the load circuit (36). A compensation circuit (30) responsive to the operation of the switched mode power supply produces variations in current in an inductance (L2) coupled to the flyback transformer (T1). These variations are indicative of variations in load current drawn by the load circuit (36). The flyback transformer (T1) couples the inductance (L2) to the retrace resonant circuit (Cr) for a variable amount of time during retrace to control the transformer trace-retrace duty cycle in a manner that compensates for retrace time modulation due to loading variations. <IMAGE> |
