| 摘要 |
PURPOSE:To eliminate the need for an exclusive auxiliary power supply circuit and accordingly to avoid the loss of electric power, by receiving the electric power from an input power supply during starting and from a voltage converting circuit during stable working respectively for the auxiliary power supply for an output controlling circuit. CONSTITUTION:When the input power supply voltage V1 is supplied between input terminals 1 and 2, the voltage lower than a prescribed level is applied to an auxiliary power supply terminal 11 of a controlling circuit 6 since an intermediate terminal 10 of a voltage converting circuit 7' receives no application of the voltage of a prescribed level at first. Then the circuit 6 starts to control the circuit 7', and the circuit 7' has the steady working. Thus the voltage of a prescribed level is applied to the terminal 10. As a result, the voltage of a prescribed level is applied to the terminal 11 via a diode 9, and a diode 8 is interrupted. After this, the circuit 6 continues the steady control operation, and the circuit 7' transmits the stable output voltage V2 between an output power supply terminals 3 and 4. |
