| 摘要 |
PURPOSE:To gain stabilized output in the range from complete no load to a full load by a method wherein pulse length control is performed at the current fluctuating time in the stationary state, while in the state of choke cut-off or overcurrent, pulse length is kept constant to perform frequency control. CONSTITUTION:The conversion main circuit (not illustrated), wherein two transistors, which alternately turn on-off, are connected with the primary winding of a transformer to gain DC output by rectifying the secondary winding output, is on- off controlled by the output of the AND circuits 2, 3 of the control section of said transistors. At the time of stationary operation of the main circuit, the fluctuation is met with pulse length control by the output voltage detection and comparison amplifier AMP 1, the load current detection and comparison amplifier AMP 2 as well as by the oscillator. When the output of AMP 1 or of AMP 2 exceeds the prescribed value fluctuating value, the oscillation frequency of OSC fluctuates to shift to the frequency control of the fixed pulse length. |
