| 摘要 |
PURPOSE:To reduce accumulating energy, attendant upon the drop of the output voltage at overload, and reducing the current supplied to load, and facilitate the control at overload, and also, secure safety by providing a control means, which varies the accumulating energy in a transformer, according to the output voltage supplied to load. CONSTITUTION:In a self-excited oscillating circuit, which feeds bath the output of tertiary winding N3 to the base of a transistor 7 through a capacitor C2 and resistors R4 and R5, a voltage doubling rectifying circuit 2 is connected in parallel with the constant voltage circuit 1. What is more, a base current 12 is adjusted so that the current 13 flowing through the primary winding N1 may be constant regardless of the existence of the voltage doubling rectifying circuit 2. Here, in case that the load resistance of load RL drops and the output voltage drops, safety is secured by preventing an overcurrent from flowing even if the DC component by the voltage doubling rectifying circuit 2 drops together with the output voltage and also the current I3 flowing through the primary winding N1 and the accumulating energy of a core drops and load RL becomes overload. |
