| 摘要 |
PURPOSE:To obtain a stabilized power supply circuit having high accuracy which can correspond even to a change of frequency, by using a stabilized control circuit using an automatic control system to stabilize the charging degree of a capacitor and stabilizing the AC voltage to control a load control circuit. CONSTITUTION:The AC voltage is applied to a series circuit of a diode D5 functioning as a rectifying element and a capacitor C1 via a resistance R2 and a diode bridge DB. The voltage of the capacitor C1 to the input of a switching transistor Q3 via a Zener diode ZD3, and the output of the Q3 is connected in parallel to a series circuit of the D5 and C1 to form an automatic control system which keeps the charging degree of the C1 at a certain level. Thus a stabilized control circuit 1 is obtained. Then a suppressing circuit 3 is added to suppress the electric quantity to be applied to a load 4 from an AC power supply 2 in response to the control potential at the point of connection between the R2 and D5 to ensure the satisfactory countermeasures to a change of frequency. |
