| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the design and manufacture by lessening the margin in design. SOLUTION: With a composite resonance type switching converter equipped with a self-excited voltage resonance type converter as basic constitution, detection winding AN, drive winding NB for a drive circuit, and control winding Nc are wound on a drive transformer CDT. Besides, this switching power circuit is provided with a circuit where the control winding Nc and the conduction control element Q2 are connected in series. As regards stabilization, the switching frequency is variably controlled by varying the level of a base current flowing to the base of the switching element Q1 from a self-excited oscillation drive circuit by varying the quantity of current conduction of the conduction control element Q2. Consequently, fixed voltage control is materialized by the composite control system where the conduction angle and the switching frequency of the switching element are varied at the same time, so that it becomes possible to omit an orthogonal control transformer. |
