| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control circuit of a switching power supply device and the switching power supply device which can reduce power consumption during standby while ensuring safety. <P>SOLUTION: A control circuit of a switching power supply device which converts input voltage supplied by an AC power supply or a DC power supply to desired output voltage by a switching action of a switching element Q1, and supplies it to a load comprises: an input voltage detection circuit which is connected to between input terminals to which input voltage is supplied, detects the input voltage and outputs a detection signal, and is composed of a first resistance R1, a switch M1, and a second resistance R2; a low input voltage action prohibition circuit making the switching action of the switching element stop when the detection signal becomes equal to or lower than a first threshold value; an output voltage detection circuit detecting the output voltage and outputting a feedback signal according to the output voltage; and a switch control circuit 10a turning off a switch by making the switching action of the switching element stop when the feedback signal becomes equal to or lower than a second threshold value in the case that the load is in a standby state. <P>COPYRIGHT: (C)2013,JPO&INPIT |
