| 摘要 |
PURPOSE:To obtain a circuit with which the power factor can be improved greatly, by giving a control to the on pulse signal of a current intermitting element so that the current equivalent to the power supply current is actuated continuously between tne upper and lower limit levels which are set previously. CONSTITUTION:The chock coil 6 and furthermore the rectifying circuit 2, switching circuit 5 and smoothing capacitor 3 are connected to the commercial power source 1 to supply the electric power to the load 4. The current to be supplied is detected by the current detector 28 and amplified by the amplifier 21 to be checked by the comparators 22 and 23 whether the current has reached up to the upper or lower limit level. The outputs of the comparators 22 and 23 are sent to the switching circuit 5 via the flip-flop 26 and driver circuit 27 to suppress the on signal of the transistor 5a when the current reaches the upper limit level. And the on signal is produced when the current reaches the lower limit level. |
