| 摘要 |
Disclosed is a charging current control circuit that controls the charging current of a smoothing capacitor which is charged by a rectifier circuit, wherein a first switching element (SCR1) is connected between a first node (N1) to which an output voltage of the rectifier circuit is applied, and a second node (N2) that is connected to a positive electrode of the smoothing capacitor. When the value of a conduction control signal (Sg), which is generated on the basis of the voltage of a first timing capacitor (C1) charged by the voltage of the first node (N1), becomes equal to or higher than a threshold voltage of a second switching element (SCR2), the second switching element and the first switching element successively change from a non-conducting state to a conducting state. Thus, in cases of switching the charging path of the smoothing capacitor at turn-on to a thyristor, there is no need for a gate-triggering transformer for controlling the conduction of the thyristor, and an increase in size of the power supply circuit is prevented. |
